LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> Subaru >> 2019 >> WRX Base >> Repair and Diagnosis >> Engine Performance >> System >> Engine Control System (Diagnostics) (Except For STI) (3 Of 4) >> Diagnostic Procedure With Diagnostic Trouble Code (DTC) >> DTC P1604: Startability Malfunction >> Notes
April 5, 2026: LEMON Manuals is launched! Read the announcement.

DTC P1604: Startability Malfunction: Notes

DTC detecting condition: 

Immediately at fault recognition

CAUTION:
NOTE: This DTC may be detected even if fault does not occur in the vehicle. If the customer does not ask for inspection, perform the clear memory mode without inspection and return the vehicle to the user.

Wiring diagram: 

Engine Electrical System Refer to WIRING SYSTEM>ENGINE ELECTRICAL SYSTEM>WIRING DIAGRAM .

G11577155Courtesy of SUBARU OF AMERICA, INC.
G11577041Courtesy of SUBARU OF AMERICA, INC.
G11577040Courtesy of SUBARU OF AMERICA, INC.
G11577042Courtesy of SUBARU OF AMERICA, INC.
G11577043Courtesy of SUBARU OF AMERICA, INC.
G11577062Courtesy of SUBARU OF AMERICA, INC.
G09480903Courtesy of SUBARU OF AMERICA, INC.
G11577160Courtesy of SUBARU OF AMERICA, INC.
G11577165Courtesy of SUBARU OF AMERICA, INC.
  1. CHECK DTC. 

    Read the engine DTC using the Subaru Select Monitor or general scan tool. Refer to ENGINE (DIAGNOSTICS) (EXCEPT FOR STI)>READ DIAGNOSTIC TROUBLE CODE (DTC) .

    Is other than DTC P1604 displayed? (Current malfunction)

    Yes:  Check DTC using "List of Diagnostic Trouble Code (DTC)". Refer to ENGINE (DIAGNOSTICS) (EXCEPT FOR STI)>LIST OF DIAGNOSTIC TROUBLE CODE (DTC) .

    No:  Go to  2.

  2. CHECK IMMOBILIZER. 

    Check the immobilizer. Refer to IMMOBILIZER (DIAGNOSTICS)>BASIC DIAGNOSTIC PROCEDURE .

    Is the check result OK?

    Yes:  Go to  3.

    No:  Repair the immobilizer. Refer to IMMOBILIZER (DIAGNOSTICS)>BASIC DIAGNOSTIC PROCEDURE .

  3. CHECK FOR MALFUNCTION OCCURRENCE. 

    Check for the condition of fault occurrence.

    Is it possible to reproduce the faulty phenomenon or to identify the faulty condition?

    Yes:  Go to  30.

    No:  Go to  4.

  4. CHECK FREEZE FRAME DATA. 

    Using the Subaru Select Monitor, read the values in «Engine Speed» and «Control module voltage».

    NOTE: For detailed operation procedures, refer to "Freeze Frame Data Display For Engine". Refer to ENGINE (DIAGNOSTICS) (EXCEPT FOR STI)>SUBARU SELECT MONITOR>OPERATION>DISPLAY OF ENGINE FREEZE FRAME DATA .

    Is the value of «Engine Speed» 0 rpm?

    Yes 

    No 

    • When the value of «Engine Speed» is less than 250 rpm: Go to  12.
    • When the value of «Engine Speed» is 250 rpm or more: Go to  20.
  5. CHECK FREEZE FRAME DATA. 

    Read the value of «Control module voltage» using Subaru Select Monitor.

    NOTE: For detailed operation procedures, refer to "Freeze Frame Data Display For Engine". Refer to ENGINE (DIAGNOSTICS) (EXCEPT FOR STI)>SUBARU SELECT MONITOR>OPERATION>DISPLAY OF ENGINE FREEZE FRAME DATA .

    Is the value of «Control module voltage» less than 9 V?

    Yes:  It is possible that the engine friction is too large. Check the engine. Refer to MECHANICAL (EXCEPT FOR STI)>SYMPTOMS AND CAUSES>INSPECTION .

    No 

  6. CHECK INSTALLATION CONDITION OF CRANKSHAFT POSITION SENSOR. 

    Check installation condition of the crankshaft position sensor.

    Is the crankshaft position sensor installed correctly?

    Yes:  Go to  7.

    No:  Install the crankshaft position sensor correctly. Refer to FUEL INJECTION (FUEL SYSTEMS) (EXCEPT FOR STI)>CRANKSHAFT POSITION SENSOR>INSTALLATION .

  7. CHECK CRANKSHAFT POSITION SENSOR. 

    Check the crankshaft position sensor. Refer to FUEL INJECTION (FUEL SYSTEMS) (EXCEPT FOR STI)>CRANKSHAFT POSITION SENSOR>INSPECTION .

    Is the check result OK?

    Yes:  Go to  8.

    No:  Replace the crankshaft position sensor. Refer to FUEL INJECTION (FUEL SYSTEMS) (EXCEPT FOR STI)>CRANKSHAFT POSITION SENSOR .

  8. CHECK POWER SUPPLY TO CRANKSHAFT POSITION SENSOR. 
    1. Turn the ignition switch to OFF.
    2. Disconnect the connector from the crankshaft position sensor.
    3. Turn the ignition switch to ON.
    4. Measure the voltage between crankshaft position sensor connector and engine ground.

      Connector & terminal 

      (E10) No. 1 (+) - Engine ground (-):

    Is the voltage 10 V or more?

    Yes:  Go to  9.

    No:  Repair the power supply circuit.

  9. CHECK HARNESS BETWEEN ECM AND CRANKSHAFT POSITION SENSOR CONNECTOR. 
    1. Turn the ignition switch to OFF.
    2. Disconnect the connector from ECM.
    3. Measure the resistance of harness between ECM connector and crankshaft position sensor connector.

      Connector & terminal 

      (E158) No. 19 - (E10) No. 2:

      (E158) No. 31 - (E10) No. 3:

    Is the resistance less than 1 Ω?

    Yes:  Go to  10.

    No:  Repair the open circuit in the harness between the ECM connector and crankshaft position sensor connector.

  10. CHECK HARNESS BETWEEN ECM AND CRANKSHAFT POSITION SENSOR CONNECTOR. 

    Measure the resistance between crankshaft position sensor connector and engine ground.

    Connector & terminal 

    (E10) No. 2 - Engine ground:

    Is the resistance 1 MΩ or more?

    Yes:  Go to  11.

    No:  Repair short circuit to ground in harness between ECM connector and crankshaft position sensor connector.

  11. CHECK FOR MALFUNCTION OCCURRENCE. 
    1. Replace the crankshaft position sensor. Refer to FUEL INJECTION (FUEL SYSTEMS) (EXCEPT FOR STI)>CRANKSHAFT POSITION SENSOR .
    2. Check that the fault is removed.

    Is the fault removed?

    Yes:  Perform the Clear Memory Mode to complete. Refer to ENGINE (DIAGNOSTICS) (EXCEPT FOR STI)>CLEAR MEMORY MODE .

    No:  Replace the ECM. Refer to FUEL INJECTION (FUEL SYSTEMS) (EXCEPT FOR STI)>ENGINE CONTROL MODULE (ECM) .

  12. CHECK FREEZE FRAME DATA. 

    Using the Subaru Select Monitor, read the values in «Coolant Temp.», «Ambient Temperature» and «Fuel Pump Duty».

    NOTE: For detailed operation procedures, refer to "Freeze Frame Data Display For Engine". Refer to ENGINE (DIAGNOSTICS) (EXCEPT FOR STI)>SUBARU SELECT MONITOR>OPERATION>DISPLAY OF ENGINE FREEZE FRAME DATA .

    Is the value of «Coolant Temp.» 120°C (248°F) or more? Or, is the value of «Coolant Temp.» lower than «Ambient Temperature» by 15°C (27°F) or more?

    Yes:  Replace the engine coolant temperature sensor. Refer to FUEL INJECTION (FUEL SYSTEMS) (EXCEPT FOR STI)>ENGINE COOLANT TEMPERATURE SENSOR .

    No 

  13. CHECK OF FUEL PUMP. 
    1. On the «Active Test» item, select «Fuel Pump Relay», and perform ON/OFF drive operation.
      NOTE: For detailed operation procedures, refer to the "Active Test". Refer to ENGINE (DIAGNOSTICS) (EXCEPT FOR STI)>ACTIVE TEST .
    2. Check if operating sound occurs in the fuel pump according to ON/OFF switching operation.

    Does the fuel pump emit operating sound?

    Yes:  Go to  15.

    No:  Go to  14.

  14. CHECK OF FUEL PUMP. 

    Check fuel pump. Refer to FUEL INJECTION (FUEL SYSTEMS) (EXCEPT FOR STI)>FUEL PUMP>INSPECTION .

    Is the check result OK?

    Yes:  Check fuel pump system. Refer to ENGINE (DIAGNOSTICS) (EXCEPT FOR STI)>DIAGNOSTIC PROCEDURE WITH DIAGNOSTIC TROUBLE CODE (DTC)>DTC P0230 FUEL PUMP PRIMARY CIRCUIT .

    No:  Replace the fuel pump. Refer to FUEL INJECTION (FUEL SYSTEMS) (EXCEPT FOR STI)>FUEL PUMP .

  15. CHECK FUEL TANK. 
    WARNING: Place "NO OPEN FLAMES" signs near the working area.

    Check if any foreign matters such as iron powder exist in the fuel tank.

    Is there any foreign matter in the fuel tank?

    Yes:  Remove foreign matter from the fuel tank.

    No:  Go to  16.

  16. CHECK FUEL PRESSURE. 
    WARNING: Place "NO OPEN FLAMES" signs near the working area.
    CAUTION:
    • Be careful not to spill fuel.
    • Before attaching/detaching a fuel pressure gauge, release the fuel pressure.

    Measure the fuel pressure. Refer to MECHANICAL (EXCEPT FOR STI)>FUEL PRESSURE>INSPECTION .

    Is the measured value 340 - 400 kPa (3.5 - 4.1 kgf/cm2 , 49 - 58 psi)?

    Yes:  Go to  17.

    No:  Check the fuel pump and fuel delivery line. Refer to FUEL INJECTION (FUEL SYSTEMS) (EXCEPT FOR STI)>FUEL PUMP>INSPECTION . Refer to FUEL INJECTION (FUEL SYSTEMS) (EXCEPT FOR STI)>FUEL DELIVERY AND EVAPORATION LINES>INSPECTION .

  17. CHECK FREEZE FRAME DATA. 

    Using the Subaru Select Monitor, read the values in «Fuel Rail Pressure A» and «Commanded Fuel Rail Pressure A».

    NOTE: For detailed operation procedures, refer to "Freeze Frame Data Display For Engine". Refer to ENGINE (DIAGNOSTICS) (EXCEPT FOR STI)>SUBARU SELECT MONITOR>OPERATION>DISPLAY OF ENGINE FREEZE FRAME DATA .

    Is the value in «Fuel Rail Pressure A» synchronized with the one in «Commanded Fuel Rail Pressure A» in all freeze frame data?

    Yes:  Go to  18.

    No:  Check the high-pressure fuel pump. Refer to FUEL INJECTION (FUEL SYSTEMS) (EXCEPT FOR STI)>HIGH PRESSURE FUEL PUMP>INSPECTION .

  18. CHECK HARNESS BETWEEN ECM AND FUEL INJECTOR CONNECTOR. 
    1. Turn the ignition switch to OFF.
    2. Disconnect the connector from ECM.
    3. Disconnect the connector from fuel injector.
    4. Measure the resistance of harness between ECM connector and fuel injector connector.

      Connector & terminal 

      #1 (E158) No. 12 - (E5) No. 1:

      #1 (E158) No. 11 - (E5) No. 2:

      #2 (E158) No. 24 - (E16) No. 1:

      #2 (E158) No. 23 - (E16) No. 2:

      #3 (E158) No. 36 - (E6) No. 1:

      #3 (E158) No. 35 - (E6) No. 2:

      #4 (E158) No. 48 - (E17) No. 1:

      #4 (E158) No. 47 - (E17) No. 2:

    Is the resistance less than 1 Ω?

    Yes:  Go to  19.

    No:  Repair the open circuit of the harness between the ECM connector and fuel injector connector.

  19. CHECK HARNESS BETWEEN ECM AND FUEL INJECTOR CONNECTOR. 

    Measure the resistance between the ECM connector and engine ground.

    Connector & terminal 

    #1 (E158) No. 12 - Engine ground:

    #1 (E158) No. 11 - Engine ground:

    #2 (E158) No. 24 - Engine ground:

    #2 (E158) No. 23 - Engine ground:

    #3 (E158) No. 36 - Engine ground:

    #3 (E158) No. 35 - Engine ground:

    #4 (E158) No. 48 - Engine ground:

    #4 (E158) No. 47 - Engine ground:

    Is the resistance 1 MΩ or more?

    Yes:  Go to  29.

    No:  Repair the short circuit to ground in harness between ECM connector and fuel injector connector.

  20. CHECK FREEZE FRAME DATA. 

    Using the Subaru Select Monitor, read the values in «Coolant Temp.», «Ambient Temperature» and «Engine Speed».

    NOTE: For detailed operation procedures, refer to "Freeze Frame Data Display For Engine". Refer to ENGINE (DIAGNOSTICS) (EXCEPT FOR STI)>SUBARU SELECT MONITOR>OPERATION>DISPLAY OF ENGINE FREEZE FRAME DATA .

    Is the value of «Coolant Temp.» 120°C (248°F) or more? Or, is the value of «Coolant Temp.» lower than «Ambient Temperature» by 15°C (27°F) or more?

    Yes:  Replace the engine coolant temperature sensor. Refer to FUEL INJECTION (FUEL SYSTEMS) (EXCEPT FOR STI)>ENGINE COOLANT TEMPERATURE SENSOR .

    No 

    • When the minimum value of «Engine Speed» is less than 300 rpm: Go to  21.
    • When the minimum value of «Engine Speed» is 300 rpm or more: It is possible that the engine compression pressure is not sufficient. Check the engine. Refer to MECHANICAL (EXCEPT FOR STI)>SYMPTOMS AND CAUSES>INSPECTION .
  21. CHECK FUEL INJECTOR. 

    Check fuel injector. Refer to FUEL INJECTION (FUEL SYSTEMS) (EXCEPT FOR STI)>FUEL INJECTOR>INSPECTION .

    Is there any deposit in the fuel injectors?

    Yes:  Replace the fuel injector. Refer to FUEL INJECTION (FUEL SYSTEMS) (EXCEPT FOR STI)>FUEL INJECTOR .

    No:  Go to  22.

  22. CHECK FUEL TANK. 
    WARNING: Place "NO OPEN FLAMES" signs near the working area.

    Check if any foreign matters such as iron powder exist in the fuel tank.

    Is there any foreign matter in the fuel tank?

    Yes:  Remove foreign matter from the fuel tank.

    No:  Go to  23.

  23. CHECK FREEZE FRAME DATA. 

    Using the Subaru Select Monitor, read the value in «Coolant Temp.».

    NOTE: For detailed operation procedures, refer to "Freeze Frame Data Display For Engine". Refer to ENGINE (DIAGNOSTICS) (EXCEPT FOR STI)>SUBARU SELECT MONITOR>OPERATION>DISPLAY OF ENGINE FREEZE FRAME DATA .

    Is the value of «Coolant Temp.» 40 - 90°C (104 - 194°F)?

    Yes:  Go to  25.

    No:  Go to  24.

  24. CHECK FUEL PRESSURE. 
    WARNING: Place "NO OPEN FLAMES" signs near the working area.
    CAUTION:
    • Be careful not to spill fuel.
    • Before attaching/detaching a fuel pressure gauge, release the fuel pressure.

    Measure the fuel pressure five minutes after the engine is stopped. Refer to MECHANICAL (EXCEPT FOR STI)>FUEL PRESSURE>INSPECTION .

    NOTE: If the engine does not start, measure the fuel pressure five minutes after cranking is completed.

    Is the measured value 147 kPa (1.5 kgf/cm2 , 21 psi) or more?

    Yes:  Go to  29.

    No:  Replace the pressure regulator. Refer to FUEL INJECTION (FUEL SYSTEMS) (EXCEPT FOR STI)>FUEL FILTER .

  25. CHECK FUEL INJECTOR. 
    1. After the engine is stopped, scavenge inside of the intake manifold by applying compressed air.
    2. Measure the HC concentration inside the intake manifold 15 minutes after scavenging is completed.

    Is the HC concentration less than 4, 000 ppm?

    Yes:  Go to  27.

    No:  Go to  26.

  26. CHECK FUEL INJECTOR. 

    Check fuel injector. Refer to FUEL INJECTION (FUEL SYSTEMS) (EXCEPT FOR STI)>FUEL INJECTOR>INSPECTION .

    Is the check result OK?

    Yes:  Go to  27.

    No:  Replace the fuel injector. Refer to FUEL INJECTION (FUEL SYSTEMS) (EXCEPT FOR STI)>FUEL INJECTOR .

  27. CHECK THROTTLE BODY. 

    Check throttle body. Refer to FUEL INJECTION (FUEL SYSTEMS) (EXCEPT FOR STI)>THROTTLE BODY>INSPECTION .

    Is there any deposit in the throttle body?

    Yes:  Replace the throttle body. Refer to FUEL INJECTION (FUEL SYSTEMS) (EXCEPT FOR STI)>THROTTLE BODY .

    No:  Go to  28.

  28. CHECK AIR INTAKE SYSTEM. 

    Check the installing condition of the air intake system.

    Are there holes, loose bolts or disconnection of hose on air intake system?

    Yes:  Repair the air intake system. Refer to INTAKE (INDUCTION) (EXCEPT FOR STI)>GENERAL DESCRIPTION .

    No:  Go to  29.

  29. CHECK FOR MALFUNCTION OCCURRENCE. 

    Check for the condition of fault occurrence.

    Is the fault removed?

    Yes:  Perform the Clear Memory Mode to complete. Refer to ENGINE (DIAGNOSTICS) (EXCEPT FOR STI)>CLEAR MEMORY MODE .

    No:  Go to  30.

  30. CHECK FOR MALFUNCTION OCCURRENCE. 

    Check for the condition of fault occurrence.

    Does cranking occur?

    Yes 

    • When the engine speed is abnormal during cranking: Go to  37.
    • When an initial combustion does not occur: Go to  40.
    • When the engine stalls immediately after engine start: Go to  57.
    • When the engine takes time to start: Go to  80.

    No:  Go to  31.

  31. CHECK FOR MALFUNCTION OCCURRENCE. 

    Check for the condition of fault occurrence.

    Does the sound occur by a protruding starter pinion gear during cranking?

    Yes 

    • When the starter motor does not rotate: Go to  32.
    • When the starter motor rotates but does not engage: Go to  34.

    No:  Go to  35.

  32. CHECK BATTERY. 

    Check the battery. Refer to STARTING/CHARGING SYSTEMS (EXCEPT FOR STI)>BATTERY>INSPECTION .

    Is the check result OK?

    Yes:  Go to  33.

    No:  Charge or replace the battery. Refer to STARTING/CHARGING SYSTEMS (EXCEPT FOR STI)>BATTERY .

  33. CHECK ENGINE MAIN BODY. 

    Using the ST, rotate the crankshaft.

    ST 18252AA000 CRANKSHAFT SOCKET 

    Does the crankshaft rotate smoothly?

    Yes:  Check the starter motor. Refer to STARTING/CHARGING SYSTEMS (EXCEPT FOR STI)>STARTER>INSPECTION .

    NOTE: It is possible that the engine friction increased temporarily. Check if any foreign matter is mixed in engine oil. If a foreign matter is found, check the engine. Refer to MECHANICAL (EXCEPT FOR STI)>SYMPTOMS AND CAUSES>INSPECTION .

    No:  It is possible that the engine friction is too large. Check the engine. Refer to MECHANICAL (EXCEPT FOR STI)>SYMPTOMS AND CAUSES>INSPECTION .

  34. CHECK STARTER MOTOR. 

    Check the starter motor. Refer to STARTING/CHARGING SYSTEMS (EXCEPT FOR STI)>STARTER>INSPECTION .

    Is there any wear or damage in the starter pinion gear?

    Yes:  Repair the starter motor. Refer to STARTING/CHARGING SYSTEMS (EXCEPT FOR STI)>STARTER .

    No 

  35. CHECK BATTERY. 

    Check the battery. Refer to STARTING/CHARGING SYSTEMS (EXCEPT FOR STI)>BATTERY>INSPECTION .

    Is the check result OK?

    Yes:  Go to  36.

    No:  Charge or replace the battery. Refer to STARTING/CHARGING SYSTEMS (EXCEPT FOR STI)>BATTERY .

  36. CHECK STARTER MOTOR. 

    Check the starter motor. Refer to STARTING/CHARGING SYSTEMS (EXCEPT FOR STI)>STARTER>INSPECTION .

    Is the check result OK?

    Yes:  Check the starter motor circuit. Refer to ENGINE (DIAGNOSTICS) (EXCEPT FOR STI)>DIAGNOSTICS FOR ENGINE STARTING FAILURE>STARTER MOTOR CIRCUIT .

    No:  Repair the starter motor. Refer to STARTING/CHARGING SYSTEMS (EXCEPT FOR STI)>STARTER .

  37. CHECK CURRENT DATA. 

    Read the value of «Engine Speed» during cranking using Subaru Select Monitor.

    NOTE: For detailed operation procedures, refer to "Current Data Display For Engine". Refer to ENGINE (DIAGNOSTICS) (EXCEPT FOR STI)>SUBARU SELECT MONITOR>OPERATION>DISPLAY CURRENT ENGINE DATA .

    Is the value of «Engine Speed» 300 rpm or more?

    Yes:  It is possible that the compression pressure of the engine is not sufficient. Check the engine. Refer to MECHANICAL (EXCEPT FOR STI)>SYMPTOMS AND CAUSES>INSPECTION .

    No:  Go to  38.

  38. CHECK BATTERY. 

    Check the battery. Refer to STARTING/CHARGING SYSTEMS (EXCEPT FOR STI)>BATTERY>INSPECTION .

    Is the check result OK?

    Yes:  Go to  39.

    No:  Charge or replace the battery. Refer to STARTING/CHARGING SYSTEMS (EXCEPT FOR STI)>BATTERY .

  39. CHECK ENGINE MAIN BODY. 

    Using the ST, rotate the crankshaft.

    ST 18252AA000 CRANKSHAFT SOCKET 

    Does the crankshaft rotate smoothly?

    Yes:  Check the starter motor. Refer to STARTING/CHARGING SYSTEMS (EXCEPT FOR STI)>STARTER>INSPECTION .

    NOTE: It is possible that the engine friction increased temporarily. Check if any foreign matter is mixed in engine oil. If a foreign matter is found, check the engine. Refer to MECHANICAL (EXCEPT FOR STI)>SYMPTOMS AND CAUSES>INSPECTION .

    No:  It is possible that the engine friction is too large. Check the engine. Refer to MECHANICAL (EXCEPT FOR STI)>SYMPTOMS AND CAUSES>INSPECTION .

  40. CHECK OPERATION OF EACH FUEL INJECTOR. 

    Using a sound scope, check each fuel injector for operation sound during cranking.

    Does the fuel injector emit operating sound?

    Yes:  Go to  41.

    No:  Go to  54.

  41. CHECK FUEL PRESSURE. 
    WARNING: Place "NO OPEN FLAMES" signs near the working area.
    CAUTION:
    • Be careful not to spill fuel.
    • Before attaching/detaching a fuel pressure gauge, release the fuel pressure.

    Measure the fuel pressure. Refer to MECHANICAL (EXCEPT FOR STI)>FUEL PRESSURE>INSPECTION .

    Is the measured value 340 - 400 kPa (3.5 - 4.1 kgf/cm2 , 49 - 58 psi)?

    Yes:  Go to  42.

    No:  Go to  52.

  42. CHECK IGNITION CONDITION. 

    Check the ignition condition. Refer to ENGINE (DIAGNOSTICS) (EXCEPT FOR STI)>DIAGNOSTICS FOR ENGINE STARTING FAILURE>IGNITION CONTROL SYSTEM .

    Is the check result OK?

    Yes:  Go to  43.

    No:  Go to  46.

  43. CHECK FOR MALFUNCTION OCCURRENCE. 

    Check for the condition of fault occurrence.

    Does the fault occur only within approx. 15 to 120 minutes after the engine is stopped?

    Yes:  Go to  45.

    No 

    • When the fault occurs in two or three minutes or a long time after the engine is stopped: Go to  44.
    • When the fault occurrence pattern is inconsistent: Go to  94.
  44. CHECK FUEL PRESSURE. 
    WARNING: Place "NO OPEN FLAMES" signs near the working area.
    CAUTION:
    • Be careful not to spill fuel.
    • Before attaching/detaching a fuel pressure gauge, release the fuel pressure.

    Measure the fuel pressure five minutes after the engine is stopped. Refer to MECHANICAL (EXCEPT FOR STI)>FUEL PRESSURE>INSPECTION .

    NOTE: If the engine does not start, measure the fuel pressure five minutes after cranking is completed.

    Is the measured value 147 kPa (1.5 kgf/cm2 , 21 psi) or more?

    Yes:  Go to  94.

    No:  Replace the pressure regulator. Refer to FUEL INJECTION (FUEL SYSTEMS) (EXCEPT FOR STI)>FUEL FILTER .

  45. CHECK FUEL INJECTOR. 
    1. After the engine is stopped, scavenge inside of the intake manifold by applying compressed air.
    2. Measure the HC concentration inside the intake manifold 15 minutes after scavenging is completed.

    Is the HC concentration less than 4, 000 ppm?

    Yes:  Go to  94.

    No:  Replace the fuel injector. Refer to FUEL INJECTION (FUEL SYSTEMS) (EXCEPT FOR STI)>FUEL INJECTOR .

  46. CHECK SPARK PLUG. 

    Check the spark plug. Refer to IGNITION (EXCEPT FOR STI)>SPARK PLUG>INSPECTION .

    Is the check result OK?

    Yes:  Go to  47.

    No:  Replace all spark plugs on all cylinders. Refer to IGNITION (EXCEPT FOR STI)>SPARK PLUG .

  47. CHECK CURRENT DATA. 

    Record the value of «Engine Speed» during cranking using Subaru Select Monitor.

    NOTE: For detailed operation procedures, refer to "Current Data Display For Engine". Refer to ENGINE (DIAGNOSTICS) (EXCEPT FOR STI)>SUBARU SELECT MONITOR>OPERATION>DISPLAY CURRENT ENGINE DATA .

    Does the recorded value of «Engine Speed» contain data of 0 rpm?

    Yes:  It is possible that temporary fault occurs in the crankshaft position sensor circuit. Check the crankshaft position sensor circuit. Refer to ENGINE (DIAGNOSTICS) (EXCEPT FOR STI)>DIAGNOSTIC PROCEDURE WITH DIAGNOSTIC TROUBLE CODE (DTC)>DTC P0335 CRANKSHAFT POSITION SENSOR "A" CIRCUIT .

    No:  Go to  48.

  48. CHECK IGNITION COIL POWER SUPPLY CIRCUIT. 
    1. Turn the ignition switch to OFF.
    2. Disconnect the connector from ignition coil.
    3. Turn the ignition switch to ON.
    4. Measure the voltage between ignition coil connector and engine ground.

      Connector & terminal 

      (E31) No. 1 (+) - Engine ground (-):

      (E32) No. 1 (+) - Engine ground (-):

      (E33) No. 1 (+) - Engine ground (-):

      (E34) No. 1 (+) - Engine ground (-):

    Is the voltage 10 V or more?

    Yes:  Go to  49.

    No:  Repair the harness and connector.

    NOTE: In this case, repair the following item:
    • Open or short to ground in power supply circuit
    • Poor contact of coupling connector
    • Blown out of fuse
  49. CHECK HARNESS BETWEEN ECM AND IGNITION COIL CONNECTOR. 
    1. Disconnect the connector from ECM.
    2. Measure the resistance of harness between ECM connector and ignition coil connector.

      Connector & terminal 

      (E159) No. 8 - (E31) No. 2:

      (E159) No. 16 - (E32) No. 2:

      (E159) No. 24 - (E33) No. 2:

      (E159) No. 32 - (E34) No. 2:

    Is the resistance less than 1 Ω?

    Yes:  Go to  50.

    No:  Repair the open circuit in harness between ECM connector and ignition coil connector.

  50. CHECK HARNESS BETWEEN ECM AND IGNITION COIL CONNECTOR. 

    Measure the resistance of harness between ECM connector and engine ground.

    Connector & terminal 

    (E159) No. 8 - Engine ground:

    (E159) No. 16 - Engine ground:

    (E159) No. 24 - Engine ground:

    (E159) No. 32 - Engine ground:

    Is the resistance 1 MΩ or more?

    Yes:  Go to  51.

    No:  Repair the ground short circuit of harness between ECM connector and ignition coil connector.

  51. CHECK HARNESS OF IGNITION COIL GROUND CIRCUIT. 
    1. Turn the ignition switch to OFF.
    2. Measure the resistance of harness between ignition coil connector and engine ground.

      Connector & terminal 

      (E31) No. 3 - Engine ground:

      (E32) No. 3 - Engine ground:

      (E33) No. 3 - Engine ground:

      (E34) No. 3 - Engine ground:

    Is the resistance less than 5 Ω?

    Yes:  Replace the ignition coil. Refer to IGNITION (EXCEPT FOR STI)>IGNITION COIL . If the fault occurs after servicing, continue the diagnosis. Go to  99.

    No:  Repair the open circuit in harness between ignition coil connector and engine grounding terminal.

  52. CHECK OF FUEL PUMP. 
    1. On the «Active Test» item, select «Fuel Pump Relay», and perform ON/OFF drive operation.
      NOTE: For detailed operation procedures, refer to the "Active Test". Refer to ENGINE (DIAGNOSTICS) (EXCEPT FOR STI)>ACTIVE TEST .
    2. Check if operating sound occurs in the fuel pump according to ON/OFF switching operation.

    Does the fuel pump emit operating sound?

    Yes:  Check the fuel pump and fuel delivery line. Refer to FUEL INJECTION (FUEL SYSTEMS) (EXCEPT FOR STI)>FUEL PUMP>INSPECTION . Refer to FUEL INJECTION (FUEL SYSTEMS) (EXCEPT FOR STI)>FUEL DELIVERY AND EVAPORATION LINES>INSPECTION .

    No:  Go to  53.

  53. CHECK OF FUEL PUMP. 

    Check fuel pump. Refer to FUEL INJECTION (FUEL SYSTEMS) (EXCEPT FOR STI)>FUEL PUMP>INSPECTION .

    Is the check result OK?

    Yes:  Check fuel pump system. Refer to ENGINE (DIAGNOSTICS) (EXCEPT FOR STI)>DIAGNOSTIC PROCEDURE WITH DIAGNOSTIC TROUBLE CODE (DTC)>DTC P0230 FUEL PUMP PRIMARY CIRCUIT . If the fault occurs after servicing, continue the diagnosis. Go to  94.

    No:  Replace the fuel pump. Refer to FUEL INJECTION (FUEL SYSTEMS) (EXCEPT FOR STI)>FUEL PUMP .

  54. CHECK CURRENT DATA. 

    Record the value of «Engine Speed» during cranking using Subaru Select Monitor.

    NOTE: For detailed operation procedures, refer to "Current Data Display For Engine". Refer to ENGINE (DIAGNOSTICS) (EXCEPT FOR STI)>SUBARU SELECT MONITOR>OPERATION>DISPLAY CURRENT ENGINE DATA .

    Does the recorded value of «Engine Speed» contain data of 0 rpm?

    Yes:  It is possible that temporary fault occurs in the crankshaft position sensor circuit. Check the crankshaft position sensor circuit. Refer to ENGINE (DIAGNOSTICS) (EXCEPT FOR STI)>DIAGNOSTIC PROCEDURE WITH DIAGNOSTIC TROUBLE CODE (DTC)>DTC P0335 CRANKSHAFT POSITION SENSOR "A" CIRCUIT .

    No:  Go to  55.

  55. CHECK HARNESS BETWEEN ECM AND FUEL INJECTOR CONNECTOR. 
    1. Turn the ignition switch to OFF.
    2. Disconnect the connector from ECM.
    3. Disconnect the connector from fuel injector.
    4. Measure the resistance of harness between ECM connector and fuel injector connector.

      Connector & terminal 

      #1 (E158) No. 12 - (E5) No. 1:

      #1 (E158) No. 11 - (E5) No. 2:

      #2 (E158) No. 24 - (E16) No. 1:

      #2 (E158) No. 23 - (E16) No. 2:

      #3 (E158) No. 36 - (E6) No. 1:

      #3 (E158) No. 35 - (E6) No. 2:

      #4 (E158) No. 48 - (E17) No. 1:

      #4 (E158) No. 47 - (E17) No. 2:

    Is the resistance less than 1 Ω?

    Yes:  Go to  56.

    No:  Repair the open circuit of the harness between the ECM connector and fuel injector connector.

  56. CHECK HARNESS BETWEEN ECM AND FUEL INJECTOR CONNECTOR. 

    Measure the resistance between the ECM connector and engine ground.

    Connector & terminal 

    #1 (E158) No. 12 - Engine ground:

    #1 (E158) No. 11 - Engine ground:

    #2 (E158) No. 24 - Engine ground:

    #2 (E158) No. 23 - Engine ground:

    #3 (E158) No. 36 - Engine ground:

    #3 (E158) No. 35 - Engine ground:

    #4 (E158) No. 48 - Engine ground:

    #4 (E158) No. 47 - Engine ground:

    Is the resistance 1 MΩ or more?

    Yes:  Replace the ECM. Refer to FUEL INJECTION (FUEL SYSTEMS) (EXCEPT FOR STI)>ENGINE CONTROL MODULE (ECM) .

    No:  Repair the short circuit to ground in harness between ECM connector and fuel injector connector.

  57. CHECK MASS AIR FLOW AND INTAKE AIR TEMPERATURE SENSOR. 

    Check the mass air flow and intake air temperature sensor. Refer to FUEL INJECTION (FUEL SYSTEMS) (EXCEPT FOR STI)>MASS AIR FLOW AND INTAKE AIR TEMPERATURE SENSOR>INSPECTION .

    Is the check result OK?

    Yes:  Go to  58.

    No:  Go to  78.

  58. CHECK AIR INTAKE SYSTEM. 

    Check the installing condition of the air intake system.

    Are there holes, loose bolts or disconnection of hose on air intake system?

    Yes:  Repair the air intake system. Refer to INTAKE (INDUCTION) (EXCEPT FOR STI)>GENERAL DESCRIPTION .

    No:  Go to  59.

  59. CHECK ELECTRONIC THROTTLE CONTROL. 
    1. Disconnect the connectors from electronic throttle control.
    2. Start the engine with the electronic throttle control connector disconnected.

    Does the engine start?

    Yes:  Go to  60.

    No:  Go to  61.

  60. CHECK THROTTLE BODY. 

    Check throttle body. Refer to FUEL INJECTION (FUEL SYSTEMS) (EXCEPT FOR STI)>THROTTLE BODY>INSPECTION .

    Is there any deposit in the throttle body?

    Yes:  Replace the throttle body. Refer to FUEL INJECTION (FUEL SYSTEMS) (EXCEPT FOR STI)>THROTTLE BODY .

    No:  Go to  61.

  61. CHECK FREEZE FRAME DATA. 
    1. Using the Subaru Select Monitor, read the values of the followings: «VVT Adv. Ang. Amount R», «VVT Advance Target Angle Amount R», «VVT Adv. Ang. Amount L», «VVT Advance Target Angle Amount L», «Exh. VVT Retard Ang. R», «Ex VVT Retard Target Angle R», «Exh. VVT Retard Ang. L» and «Ex VVT Retard Target Angle L».
      NOTE: For detailed operation procedures, refer to "Freeze Frame Data Display For Engine". Refer to ENGINE (DIAGNOSTICS) (EXCEPT FOR STI)>SUBARU SELECT MONITOR>OPERATION>DISPLAY OF ENGINE FREEZE FRAME DATA .
    2. Using the Subaru Select Monitor, compare the respective values between the followings: «VVT Adv. Ang. Amount R» and «VVT Advance Target Angle Amount R», «VVT Adv. Ang. Amount L» and «VVT Advance Target Angle Amount L», «Exh. VVT Retard Ang. R» and «Ex VVT Retard Target Angle R», «Exh. VVT Retard Ang. L» and «Ex VVT Retard Target Angle L».

    Does all of the advance angle amount and retard angle amount synchronize with their target values?

    Yes:  Go to  112.

    No:  Diagnose the part where there is difference of 10 deg or more.

    • Intake RH: Go to  62.
    • Intake LH: Go to  66.
    • Exhaust RH: Go to  70.
    • Exhaust LH: Go to  74.
  62. CHECK POWER SUPPLY TO THE INTAKE OIL CONTROL SOLENOID RH. 
    1. Turn the ignition switch to OFF.
    2. Disconnect the connector from the intake oil control solenoid RH.
    3. Turn the ignition switch to ON.
    4. Measure the voltage between intake oil control solenoid RH connector and engine ground.

      Connector & terminal 

      (E38) No. 1 (+) - Engine ground (-):

    Is the voltage 10 V or more?

    Yes:  Go to  63.

    No:  Repair the power supply circuit.

  63. CHECK HARNESS BETWEEN ECM AND INTAKE OIL CONTROL SOLENOID RH CONNECTOR. 
    1. Turn the ignition switch to OFF.
    2. Disconnect the connector from ECM.
    3. Measure the resistance of harness between ECM connector and intake oil control solenoid RH.

      Connector & terminal 

      (E159) No. 7 - (E38) No. 2:

    Is the resistance less than 1 Ω?

    Yes:  Go to  64.

    No:  Repair the open circuit in harness between ECM connector and intake oil control solenoid RH connector.

  64. CHECK HARNESS BETWEEN ECM AND INTAKE OIL CONTROL SOLENOID RH CONNECTOR. 

    Measure the resistance between intake oil control solenoid RH connector and engine ground.

    Connector & terminal 

    (E38) No. 2 - Engine ground:

    Is the resistance 1 MΩ or more?

    Yes:  Go to  65.

    No:  Repair the short circuit to ground in harness between ECM connector and intake oil control solenoid RH connector.

  65. CHECK INTAKE OIL CONTROL SOLENOID RH. 

    Check the intake oil control solenoid RH. Refer to FUEL INJECTION (FUEL SYSTEMS) (EXCEPT FOR STI)>OIL CONTROL SOLENOID>INSPECTION .

    Is the check result OK?

    Yes:  Replace the intake cam sprocket RH. Refer to MECHANICAL (EXCEPT FOR STI)>CAM SPROCKET .

    No:  Replace the intake oil control solenoid RH. Refer to FUEL INJECTION (FUEL SYSTEMS) (EXCEPT FOR STI)>OIL CONTROL SOLENOID .

  66. CHECK POWER SUPPLY TO THE INTAKE OIL CONTROL SOLENOID LH. 
    1. Turn the ignition switch to OFF.
    2. Disconnect the connector from the intake oil control solenoid LH.
    3. Turn the ignition switch to ON.
    4. Measure the voltage between intake oil control solenoid LH connector and engine ground.

      Connector & terminal 

      (E37) No. 1 (+) - Engine ground (-):

    Is the voltage 10 V or more?

    Yes:  Go to  67.

    No:  Repair the power supply circuit.

  67. CHECK HARNESS BETWEEN ECM AND INTAKE OIL CONTROL SOLENOID LH CONNECTOR. 
    1. Turn the ignition switch to OFF.
    2. Disconnect the connector from ECM.
    3. Measure the resistance of harness between ECM connector and intake oil control solenoid LH.

      Connector & terminal 

      (E159) No. 15 - (E37) No. 2:

    Is the resistance less than 1 Ω?

    Yes:  Go to  68.

    No:  Repair the open circuit in harness between ECM connector and intake oil control solenoid LH connector.

  68. CHECK HARNESS BETWEEN ECM AND INTAKE OIL CONTROL SOLENOID LH CONNECTOR. 

    Measure the resistance between intake oil control solenoid LH connector and engine ground.

    Connector & terminal 

    (E37) No. 2 - Engine ground:

    Is the resistance 1 MΩ or more?

    Yes:  Go to  69.

    No:  Repair the short circuit to ground in harness between ECM connector and intake oil control solenoid LH connector.

  69. CHECK INTAKE OIL CONTROL SOLENOID LH. 

    Check the intake oil control solenoid LH. Refer to FUEL INJECTION (FUEL SYSTEMS) (EXCEPT FOR STI)>OIL CONTROL SOLENOID>INSPECTION .

    Is the check result OK?

    Yes:  Replace the intake cam sprocket LH. Refer to MECHANICAL (EXCEPT FOR STI)>CAM SPROCKET .

    No:  Replace the intake oil control solenoid LH. Refer to FUEL INJECTION (FUEL SYSTEMS) (EXCEPT FOR STI)>OIL CONTROL SOLENOID .

  70. CHECK POWER SUPPLY TO THE EXHAUST OIL CONTROL SOLENOID RH. 
    1. Turn the ignition switch to OFF.
    2. Disconnect the connector from the exhaust oil control solenoid RH.
    3. Turn the ignition switch to ON.
    4. Measure the voltage between exhaust oil control solenoid RH connector and engine ground.

      Connector & terminal 

      (E63) No. 1 (+) - Engine ground (-):

    Is the voltage 10 V or more?

    Yes:  Go to  71.

    No:  Repair the power supply circuit.

  71. CHECK HARNESS BETWEEN ECM AND EXHAUST OIL CONTROL SOLENOID RH CONNECTOR. 
    1. Turn the ignition switch to OFF.
    2. Disconnect the connector from ECM.
    3. Measure the resistance of harness between ECM connector and exhaust oil control solenoid RH.

      Connector & terminal 

      (E159) No. 23 - (E63) No. 2:

    Is the resistance less than 1 Ω?

    Yes:  Go to  72.

    No:  Repair the open circuit in harness between ECM connector and exhaust oil control solenoid RH connector.

  72. CHECK HARNESS BETWEEN ECM AND EXHAUST OIL CONTROL SOLENOID RH CONNECTOR. 

    Measure the resistance between exhaust oil control solenoid RH connector and engine ground.

    Connector & terminal 

    (E63) No. 2 - Engine ground:

    Is the resistance 1 MΩ or more?

    Yes:  Go to  73.

    No:  Repair the short circuit to ground in harness between ECM connector and exhaust oil control solenoid RH connector.

  73. CHECK EXHAUST OIL CONTROL SOLENOID RH. 

    Check the exhaust oil control solenoid RH. Refer to FUEL INJECTION (FUEL SYSTEMS) (EXCEPT FOR STI)>OIL CONTROL SOLENOID>INSPECTION .

    Is the check result OK?

    Yes:  Replace the exhaust cam sprocket RH. Refer to MECHANICAL (EXCEPT FOR STI)>CAM SPROCKET .

    No:  Replace the exhaust oil control solenoid RH. Refer to FUEL INJECTION (FUEL SYSTEMS) (EXCEPT FOR STI)>OIL CONTROL SOLENOID .

  74. CHECK POWER SUPPLY TO THE EXHAUST OIL CONTROL SOLENOID LH. 
    1. Turn the ignition switch to OFF.
    2. Disconnect the connector from the exhaust oil control solenoid LH.
    3. Turn the ignition switch to ON.
    4. Measure the voltage between exhaust oil control solenoid LH connector and engine ground.

      Connector & terminal 

      (E66) No. 1 (+) - Engine ground (-):

    Is the voltage 10 V or more?

    Yes:  Go to  75.

    No:  Repair the power supply circuit.

  75. CHECK HARNESS BETWEEN ECM AND EXHAUST OIL CONTROL SOLENOID LH CONNECTOR. 
    1. Turn the ignition switch to OFF.
    2. Disconnect the connector from ECM.
    3. Measure the resistance of harness between ECM connector and exhaust oil control solenoid LH.

      Connector & terminal 

      (E159) No. 31 - (E66) No. 2:

    Is the resistance less than 1 Ω?

    Yes:  Go to  76.

    No:  Repair the open circuit in harness between ECM connector and exhaust oil control solenoid LH connector.

  76. CHECK HARNESS BETWEEN ECM AND EXHAUST OIL CONTROL SOLENOID LH CONNECTOR. 

    Measure the resistance between exhaust oil control solenoid LH connector and engine ground.

    Connector & terminal 

    (E66) No. 2 - Engine ground:

    Is the resistance 1 MΩ or more?

    Yes:  Go to  77.

    No:  Repair the short circuit to ground in harness between ECM connector and exhaust oil control solenoid LH connector.

  77. CHECK EXHAUST OIL CONTROL SOLENOID LH. 

    Check the exhaust oil control solenoid LH. Refer to FUEL INJECTION (FUEL SYSTEMS) (EXCEPT FOR STI)>OIL CONTROL SOLENOID>INSPECTION .

    Is the check result OK?

    Yes:  Replace the exhaust cam sprocket LH. Refer to MECHANICAL (EXCEPT FOR STI)>CAM SPROCKET .

    No:  Replace the exhaust oil control solenoid LH. Refer to FUEL INJECTION (FUEL SYSTEMS) (EXCEPT FOR STI)>OIL CONTROL SOLENOID .

  78. CHECK HARNESS BETWEEN ECM AND MASS AIR FLOW AND INTAKE AIR TEMPERATURE SENSOR CONNECTOR. 
    1. Turn the ignition switch to OFF.
    2. Disconnect the connector from ECM.
    3. Disconnect the connectors from the mass air flow and intake air temperature sensor.
    4. Measure the resistance of harness between ECM connector and the mass air flow and intake air temperature sensor connector.

      Connector & terminal 

      (B134) No. 16 - (B3) No. 3:

      (B134) No. 28 - (B3) No. 2:

    Is the resistance less than 1 Ω?

    Yes:  Go to  79.

    No:  Repair the open circuit of harness between ECM connector and the mass air flow and intake air temperature sensor connector.

  79. CHECK HARNESS BETWEEN ECM AND MASS AIR FLOW AND INTAKE AIR TEMPERATURE SENSOR CONNECTOR. 

    Measure the resistance between the ECM connector and engine ground.

    Connector & terminal 

    (B134) No. 16 - Engine ground:

    (B134) No. 28 - Engine ground:

    Is the resistance 1 MΩ or more?

    Yes:  Replace the mass air flow and intake air temperature sensor. Refer to FUEL INJECTION (FUEL SYSTEMS) (EXCEPT FOR STI)>MASS AIR FLOW AND INTAKE AIR TEMPERATURE SENSOR . If the fault occurs after servicing, continue the diagnosis. Go to  112.

    No:  Repair the ground short circuit of harness between ECM connector and the mass air flow and intake air temperature sensor connector.

  80. CHECK ENGINE COOLANT TEMPERATURE SENSOR. 

    Check the engine coolant temperature sensor. Refer to FUEL INJECTION (FUEL SYSTEMS) (EXCEPT FOR STI)>ENGINE COOLANT TEMPERATURE SENSOR>INSPECTION .

    Is the check result OK?

    Yes:  Go to  81.

    No:  Replace the engine coolant temperature sensor. Refer to FUEL INJECTION (FUEL SYSTEMS) (EXCEPT FOR STI)>ENGINE COOLANT TEMPERATURE SENSOR . If the fault occurs after servicing, replace the ECM. Refer to FUEL INJECTION (FUEL SYSTEMS) (EXCEPT FOR STI)>ENGINE CONTROL MODULE (ECM) . If the fault still occurs after replacing the ECM, continue the diagnosis. Go to  123.

  81. CHECK HARNESS BETWEEN ECM AND ENGINE COOLANT TEMPERATURE SENSOR CONNECTOR. 
    1. Turn the ignition switch to OFF.
    2. Disconnect the connector from ECM.
    3. Disconnect the connectors from the engine coolant temperature sensor.
    4. Measure the resistance of harness between ECM connector and engine coolant temperature sensor connector.

      Connector & terminal 

      (E159) No. 27 - (E8) No. 1:

      (E158) No. 38 - (E8) No. 2:

    Is the resistance less than 1 Ω?

    Yes:  Go to  82.

    No:  Repair the open circuit of the harness between the ECM connector and engine coolant temperature sensor connector. If the fault occurs after servicing, replace the ECM. Refer to FUEL INJECTION (FUEL SYSTEMS) (EXCEPT FOR STI)>ENGINE CONTROL MODULE (ECM) . If the fault still occurs after replacing the ECM, continue the diagnosis. Go to  123.

  82. CHECK HARNESS BETWEEN ECM AND ENGINE COOLANT TEMPERATURE SENSOR CONNECTOR. 

    Measure the resistance between the ECM connector and engine ground.

    Connector & terminal 

    (E158) No. 38 - Engine ground:

    (E159) No. 27 - Engine ground:

    Is the resistance 1 MΩ or more?

    Yes:  Go to  83.

    No:  Repair the short circuit to ground in harness between ECM connector and engine coolant temperature sensor connector. If the fault occurs after servicing, replace the ECM. Refer to FUEL INJECTION (FUEL SYSTEMS) (EXCEPT FOR STI)>ENGINE CONTROL MODULE (ECM) . If the fault still occurs after replacing the ECM, continue the diagnosis. Go to  123.

  83. CHECK CURRENT DATA. 
    1. Turn the ignition switch to ON. (Engine OFF)
    2. Read the values of «Long term fuel trim B1» and «Atmosphere Pressure», using the Subaru Select Monitor.
    NOTE: For detailed operation procedures, refer to "Current Data Display For Engine". Refer to ENGINE (DIAGNOSTICS) (EXCEPT FOR STI)>SUBARU SELECT MONITOR>OPERATION>DISPLAY CURRENT ENGINE DATA .

    Is the value of «Long term fuel trim B1»-25 - 25%, and «Atmosphere Pressure» 80 kPa (600 mmHg, 23.6 inHg) or more?

    Yes:  Go to  86.

    No:  Go to  84.

  84. CHECK FOR MALFUNCTION OCCURRENCE. 
    1. Perform the Clear Memory Mode. Refer to ENGINE (DIAGNOSTICS) (EXCEPT FOR STI)>CLEAR MEMORY MODE .
    2. Start the engine.

    Does the engine start?

    Yes:  Go to  85.

    No:  Go to  86.

  85. CHECK IDLE SPEED. 

    Check the idle speed.

    Is the idle speed stable?

    Yes:  Replace the mass air flow and intake air temperature sensor. Refer to FUEL INJECTION (FUEL SYSTEMS) (EXCEPT FOR STI)>MASS AIR FLOW AND INTAKE AIR TEMPERATURE SENSOR . If the fault occurs after servicing, replace the ECM. Refer to FUEL INJECTION (FUEL SYSTEMS) (EXCEPT FOR STI)>ENGINE CONTROL MODULE (ECM) . If the fault still occurs after replacing the ECM, continue the diagnosis. Go to  123.

    No:  Replace the fuel injector. Refer to FUEL INJECTION (FUEL SYSTEMS) (EXCEPT FOR STI)>FUEL INJECTOR . If the fault occurs after servicing, replace the ECM. Refer to FUEL INJECTION (FUEL SYSTEMS) (EXCEPT FOR STI)>ENGINE CONTROL MODULE (ECM) . If the fault still occurs after replacing the ECM, continue the diagnosis. Go to  123.

  86. CHECK FUEL PRESSURE. 
    WARNING: Place "NO OPEN FLAMES" signs near the working area.
    CAUTION:
    • Be careful not to spill fuel.
    • Before attaching/detaching a fuel pressure gauge, release the fuel pressure.

    Measure the fuel pressure. Refer to MECHANICAL (EXCEPT FOR STI)>FUEL PRESSURE>INSPECTION .

    Is the measured value 340 - 400 kPa (3.5 - 4.1 kgf/cm2 , 49 - 58 psi)?

    Yes:  Go to  87.

    No:  Go to  93.

  87. CHECK FREEZE FRAME DATA. 

    Using the Subaru Select Monitor, read the values in «Fuel Rail Pressure A» and «Commanded Fuel Rail Pressure A».

    NOTE: For detailed operation procedures, refer to "Freeze Frame Data Display For Engine". Refer to ENGINE (DIAGNOSTICS) (EXCEPT FOR STI)>SUBARU SELECT MONITOR>OPERATION>DISPLAY OF ENGINE FREEZE FRAME DATA .

    Is the value in «Fuel Rail Pressure A» synchronized with the one in «Commanded Fuel Rail Pressure A» in all freeze frame data?

    Yes:  Go to  88.

    No:  Check the high-pressure fuel pump. Refer to FUEL INJECTION (FUEL SYSTEMS) (EXCEPT FOR STI)>HIGH PRESSURE FUEL PUMP>INSPECTION .

  88. CHECK SPARK PLUG. 

    Check the spark plug. Refer to IGNITION (EXCEPT FOR STI)>SPARK PLUG>INSPECTION .

    Is the check result OK?

    Yes:  Go to  89.

    No 

    • When spark plugs in some cylinders are faulty: Replace the faulty spark plugs of the cylinders, then check the ignition system and fuel system in the faulty cylinders. Refer to IGNITION (EXCEPT FOR STI)>SPARK PLUG . If the fault occurs after servicing, continue the diagnosis. Go to  123.
    • When all spark plugs in all cylinders are faulty: Replace faulty spark plugs in all cylinders. Refer to IGNITION (EXCEPT FOR STI)>SPARK PLUG . If the fault occurs after servicing, continue the diagnosis. Go to  123.
  89. CHECK FOR MALFUNCTION OCCURRENCE. 

    Check for the condition of fault occurrence.

    Does the fault occur only within approx. 15 to 120 minutes after the engine is stopped?

    Yes:  Go to  91.

    No 

    • When the fault occurs in two or three minutes or a long time after the engine is stopped: Go to  90.
    • When the fault occurrence pattern is inconsistent: Go to  123.
  90. CHECK FUEL PRESSURE. 
    WARNING: Place "NO OPEN FLAMES" signs near the working area.
    CAUTION:
    • Be careful not to spill fuel.
    • Before attaching/detaching a fuel pressure gauge, release the fuel pressure.

    Measure the fuel pressure five minutes after the engine is stopped. Refer to MECHANICAL (EXCEPT FOR STI)>FUEL PRESSURE>INSPECTION .

    NOTE: If the engine does not start, measure the fuel pressure five minutes after cranking is completed.

    Is the measured value 147 kPa (1.5 kgf/cm2 , 21 psi) or more?

    Yes:  Go to  123.

    No:  Replace the pressure regulator. Refer to FUEL INJECTION (FUEL SYSTEMS) (EXCEPT FOR STI)>FUEL FILTER .

  91. CHECK PURGE CONTROL SOLENOID VALVE. 

    Check purge control solenoid valve 1 and purge control solenoid valve 2. Refer to EMISSION CONTROL (AUX. EMISSION CONTROL DEVICES) (EXCEPT FOR STI)>PURGE CONTROL SOLENOID VALVE>INSPECTION .

    Is the check result OK?

    Yes:  Go to  92.

    No:  Replace the faulty purge control solenoid valve. Refer to EMISSION CONTROL (AUX. EMISSION CONTROL DEVICES) (EXCEPT FOR STI)>PURGE CONTROL SOLENOID VALVE .

  92. CHECK FUEL INJECTOR. 
    1. After the engine is stopped, scavenge inside of the intake manifold by applying compressed air.
    2. Measure the HC concentration inside the intake manifold 15 minutes after scavenging is completed.

    Is the HC concentration less than 4, 000 ppm?

    Yes:  Go to  123.

    No:  Replace the fuel injector. Refer to FUEL INJECTION (FUEL SYSTEMS) (EXCEPT FOR STI)>FUEL INJECTOR .

  93. CHECK OF FUEL PUMP. 

    Check fuel pump. Refer to FUEL INJECTION (FUEL SYSTEMS) (EXCEPT FOR STI)>FUEL PUMP>INSPECTION .

    Is the check result OK?

    Yes:  Check fuel pump system. Refer to ENGINE (DIAGNOSTICS) (EXCEPT FOR STI)>DIAGNOSTIC PROCEDURE WITH DIAGNOSTIC TROUBLE CODE (DTC)>DTC P0230 FUEL PUMP PRIMARY CIRCUIT . If the fault occurs after servicing, continue the diagnosis. Go to  123.

    No:  Replace the fuel pump. Refer to FUEL INJECTION (FUEL SYSTEMS) (EXCEPT FOR STI)>FUEL PUMP .

  94. CHECK FUEL INJECTOR. 

    Check fuel injector. Refer to FUEL INJECTION (FUEL SYSTEMS) (EXCEPT FOR STI)>FUEL INJECTOR>INSPECTION .

    Is the check result OK?

    Yes:  Go to  95.

    No:  Replace the fuel injector. Refer to FUEL INJECTION (FUEL SYSTEMS) (EXCEPT FOR STI)>FUEL INJECTOR .

  95. CHECK HARNESS BETWEEN ECM AND FUEL INJECTOR CONNECTOR. 
    1. Turn the ignition switch to OFF.
    2. Disconnect the connector from ECM.
    3. Disconnect the connector from fuel injector.
    4. Measure the resistance of harness between ECM connector and fuel injector connector.

      Connector & terminal 

      #1 (E158) No. 12 - (E5) No. 1:

      #1 (E158) No. 11 - (E5) No. 2:

      #2 (E158) No. 24 - (E16) No. 1:

      #2 (E158) No. 23 - (E16) No. 2:

      #3 (E158) No. 36 - (E6) No. 1:

      #3 (E158) No. 35 - (E6) No. 2:

      #4 (E158) No. 48 - (E17) No. 1:

      #4 (E158) No. 47 - (E17) No. 2:

    Is the resistance less than 1 Ω?

    Yes:  Go to  96.

    No:  Repair the open circuit of the harness between the ECM connector and fuel injector connector.

  96. CHECK HARNESS BETWEEN ECM AND FUEL INJECTOR CONNECTOR. 

    Measure the resistance between the ECM connector and engine ground.

    Connector & terminal 

    #1 (E158) No. 12 - Engine ground:

    #1 (E158) No. 11 - Engine ground:

    #2 (E158) No. 24 - Engine ground:

    #2 (E158) No. 23 - Engine ground:

    #3 (E158) No. 36 - Engine ground:

    #3 (E158) No. 35 - Engine ground:

    #4 (E158) No. 48 - Engine ground:

    #4 (E158) No. 47 - Engine ground:

    Is the resistance 1 MΩ or more?

    Yes:  Go to  97.

    No:  Repair the short circuit to ground in harness between ECM connector and fuel injector connector.

  97. CHECK FOR MALFUNCTION OCCURRENCE. 
    1. Replace the crankshaft position sensor. Refer to FUEL INJECTION (FUEL SYSTEMS) (EXCEPT FOR STI)>CRANKSHAFT POSITION SENSOR .
    2. Check that the fault is removed.

    Is the fault removed?

    Yes:  Perform the Clear Memory Mode to complete. Refer to ENGINE (DIAGNOSTICS) (EXCEPT FOR STI)>CLEAR MEMORY MODE .

    No:  Go to  98.

  98. CHECK FOR MALFUNCTION OCCURRENCE. 
    1. Replace the camshaft position sensor. Refer to FUEL INJECTION (FUEL SYSTEMS) (EXCEPT FOR STI)>CAMSHAFT POSITION SENSOR .
    2. Check that the fault is removed.

    Is the fault removed?

    Yes:  Perform the Clear Memory Mode to complete. Refer to ENGINE (DIAGNOSTICS) (EXCEPT FOR STI)>CLEAR MEMORY MODE .

    No:  Replace the ECM. Refer to FUEL INJECTION (FUEL SYSTEMS) (EXCEPT FOR STI)>ENGINE CONTROL MODULE (ECM) .

  99. CHECK INSTALLATION CONDITION OF CRANKSHAFT POSITION SENSOR. 

    Check installation condition of the crankshaft position sensor.

    Is the crankshaft position sensor installed correctly?

    Yes:  Go to  100.

    No:  Install the crankshaft position sensor correctly. Refer to FUEL INJECTION (FUEL SYSTEMS) (EXCEPT FOR STI)>CRANKSHAFT POSITION SENSOR>INSTALLATION .

  100. CHECK INSTALLATION CONDITION OF CAMSHAFT POSITION SENSOR. 

    Check installation condition of the camshaft position sensor.

    Is the camshaft position sensor installed correctly?

    Yes:  Go to  101.

    No:  Install the camshaft position sensor correctly. Refer to FUEL INJECTION (FUEL SYSTEMS) (EXCEPT FOR STI)>CAMSHAFT POSITION SENSOR>INSTALLATION .

  101. CHECK POWER SUPPLY TO CRANKSHAFT POSITION SENSOR. 
    1. Turn the ignition switch to OFF.
    2. Disconnect the connector from the crankshaft position sensor.
    3. Turn the ignition switch to ON.
    4. Measure the voltage between crankshaft position sensor connector and engine ground.

      Connector & terminal 

      (E10) No. 1 (+) - Engine ground (-):

    Is the voltage 10 V or more?

    Yes:  Go to  102.

    No:  Repair the power supply circuit.

  102. CHECK HARNESS BETWEEN ECM AND CRANKSHAFT POSITION SENSOR CONNECTOR. 
    1. Turn the ignition switch to OFF.
    2. Disconnect the connector from ECM.
    3. Measure the resistance of harness between ECM connector and crankshaft position sensor connector.

      Connector & terminal 

      (E158) No. 19 - (E10) No. 2:

      (E158) No. 31 - (E10) No. 3:

    Is the resistance less than 1 Ω?

    Yes:  Go to  103.

    No:  Repair the open circuit in the harness between the ECM connector and crankshaft position sensor connector.

  103. CHECK HARNESS BETWEEN ECM AND CRANKSHAFT POSITION SENSOR CONNECTOR. 

    Measure the resistance between crankshaft position sensor connector and engine ground.

    Connector & terminal 

    (E10) No. 2 - Engine ground:

    Is the resistance 1 MΩ or more?

    Yes:  Go to  104.

    No:  Repair short circuit to ground in harness between ECM connector and crankshaft position sensor connector.

  104. CHECK POWER SUPPLY OF INTAKE CAMSHAFT POSITION SENSOR. 
    1. Turn the ignition switch to OFF.
    2. Disconnect the connector from the intake camshaft position sensor.
    3. Turn the ignition switch to ON.
    4. Measure the voltage between intake camshaft position sensor connector and engine ground.

      Connector & terminal 

      (E35) No. 1 (+) - Engine ground (-):

      (E36) No. 1 (+) - Engine ground (-):

    Is the voltage 10 V or more?

    Yes:  Go to  105.

    No:  Repair the harness and connector.

    NOTE: In this case, repair the following item:
    • Open circuit or short circuit to ground in harness between main relay connector and intake camshaft position sensor connector
    • Poor contact of coupling connector
  105. CHECK HARNESS BETWEEN ECM AND INTAKE CAMSHAFT POSITION SENSOR CONNECTOR. 
    1. Turn the ignition switch to OFF.
    2. Disconnect the connector from ECM.
    3. Measure the resistance between ECM connector and intake camshaft position sensor connector.

      Connector & terminal 

      (E158) No. 21 - (E35) No. 2:

      (E158) No. 34 - (E35) No. 3:

      (E158) No. 20 - (E36) No. 2:

      (E158) No. 34 - (E36) No. 3:

    Is the resistance less than 1 Ω?

    Yes:  Go to  106.

    No:  Repair the open circuit in the harness between ECM connector and intake camshaft position sensor connector.

  106. CHECK HARNESS BETWEEN ECM AND INTAKE CAMSHAFT POSITION SENSOR CONNECTOR. 

    Measure the resistance between intake camshaft position sensor connector and engine ground.

    Connector & terminal 

    (E35) No. 2 - Engine ground:

    (E36) No. 2 - Engine ground:

    Is the resistance 1 MΩ or more?

    Yes:  Go to  107.

    No:  Repair short circuit to ground in the harness between ECM connector and intake camshaft position sensor connector.

  107. CHECK POWER SUPPLY OF EXHAUST CAMSHAFT POSITION SENSOR. 
    1. Turn the ignition switch to OFF.
    2. Disconnect the connector from the exhaust camshaft position sensor.
    3. Turn the ignition switch to ON.
    4. Measure the voltage between exhaust camshaft position sensor connector and engine ground.

      Connector & terminal 

      (E62) No. 1 (+) - Engine ground (-):

      (E65) No. 1 (+) - Engine ground (-):

    Is the voltage 10 V or more?

    Yes:  Go to  108.

    No:  Repair the harness and connector.

    NOTE: In this case, repair the following item:
    • Open circuit in harness between main relay and exhaust camshaft position sensor connector
    • Poor contact of coupling connector
  108. CHECK HARNESS BETWEEN ECM AND EXHAUST CAMSHAFT POSITION SENSOR CONNECTOR. 
    1. Turn the ignition switch to OFF.
    2. Disconnect the connector from ECM.
    3. Measure the resistance between ECM connector and exhaust camshaft position sensor connector.

      Connector & terminal 

      (E158) No. 32 - (E62) No. 2:

      (E158) No. 34 - (E62) No. 3:

      (E158) No. 33 - (E65) No. 2:

      (E158) No. 34 - (E65) No. 3:

    Is the resistance less than 1 Ω?

    Yes:  Go to  109.

    No:  Repair the open circuit in the harness between ECM connector and exhaust camshaft position sensor connector.

  109. CHECK HARNESS BETWEEN ECM AND EXHAUST CAMSHAFT POSITION SENSOR CONNECTOR. 

    Measure the resistance between exhaust camshaft position sensor connector and engine ground.

    Connector & terminal 

    (E62) No. 2 - Engine ground:

    (E65) No. 2 - Engine ground:

    Is the resistance 1 MΩ or more?

    Yes:  Go to  110.

    No:  Repair short circuit to ground in the harness between ECM connector and exhaust camshaft position sensor connector.

  110. CHECK FOR MALFUNCTION OCCURRENCE. 
    1. Replace the crankshaft position sensor. Refer to FUEL INJECTION (FUEL SYSTEMS) (EXCEPT FOR STI)>CRANKSHAFT POSITION SENSOR .
    2. Check that the fault is removed.

    Is the fault removed?

    Yes:  Perform the Clear Memory Mode to complete. Refer to ENGINE (DIAGNOSTICS) (EXCEPT FOR STI)>CLEAR MEMORY MODE .

    No:  Go to  111.

  111. CHECK FOR MALFUNCTION OCCURRENCE. 
    1. Replace the camshaft position sensor. Refer to FUEL INJECTION (FUEL SYSTEMS) (EXCEPT FOR STI)>CAMSHAFT POSITION SENSOR .
    2. Check that the fault is removed.

    Is the fault removed?

    Yes:  Perform the Clear Memory Mode to complete. Refer to ENGINE (DIAGNOSTICS) (EXCEPT FOR STI)>CLEAR MEMORY MODE .

    No:  Replace the ECM. Refer to FUEL INJECTION (FUEL SYSTEMS) (EXCEPT FOR STI)>ENGINE CONTROL MODULE (ECM) .

  112. CHECK ENGINE COOLANT TEMPERATURE SENSOR. 

    Check the engine coolant temperature sensor. Refer to FUEL INJECTION (FUEL SYSTEMS) (EXCEPT FOR STI)>ENGINE COOLANT TEMPERATURE SENSOR>INSPECTION .

    Is the check result OK?

    Yes:  Go to  113.

    No:  Replace the engine coolant temperature sensor. Refer to FUEL INJECTION (FUEL SYSTEMS) (EXCEPT FOR STI)>ENGINE COOLANT TEMPERATURE SENSOR .

  113. CHECK FUEL PRESSURE. 
    WARNING: Place "NO OPEN FLAMES" signs near the working area.
    CAUTION:
    • Be careful not to spill fuel.
    • Before attaching/detaching a fuel pressure gauge, release the fuel pressure.

    Measure the fuel pressure during cranking and five minutes after the engine is stopped. Refer to MECHANICAL (EXCEPT FOR STI)>FUEL PRESSURE>INSPECTION .

    Is the value of the fuel pressure during cranking 304 - 353 kPa (3.1 - 3.6 kgf/cm2 , 44 - 51 psi), and is the fuel pressure five minutes after engine stop 147 kPa (1.5 kgf/cm2 , 21 psi) or more?

    Yes:  Go to  114.

    No:  Go to  122.

  114. CHECK CURRENT DATA. 
    1. Turn the ignition switch to ON. (Engine OFF)
    2. Read the value of «Long term fuel trim B1» using the Subaru Select Monitor.
    NOTE: For detailed operation procedures, refer to "Current Data Display For Engine". Refer to ENGINE (DIAGNOSTICS) (EXCEPT FOR STI)>SUBARU SELECT MONITOR>OPERATION>DISPLAY CURRENT ENGINE DATA .

    Does the value of «Long term fuel trim B1» fall within a range of -15 - 15%?

    Yes:  Go to  115.

    No:  Replace the fuel injector. Refer to FUEL INJECTION (FUEL SYSTEMS) (EXCEPT FOR STI)>FUEL INJECTOR .

  115. CHECK FOR MALFUNCTION OCCURRENCE. 

    Start the engine and check the idling speed.

    Is the idling speed stable all time?

    Yes:  It is possible that the fault comes from fuel. Replace fuel.

    No:  Go to  116.

  116. CHECK INSTALLATION CONDITION OF CRANKSHAFT POSITION SENSOR. 

    Check installation condition of the crankshaft position sensor.

    Is the crankshaft position sensor installed correctly?

    Yes:  Go to  117.

    No:  Install the crankshaft position sensor correctly. Refer to FUEL INJECTION (FUEL SYSTEMS) (EXCEPT FOR STI)>CRANKSHAFT POSITION SENSOR>INSTALLATION .

  117. CHECK POWER SUPPLY TO CRANKSHAFT POSITION SENSOR. 
    1. Turn the ignition switch to OFF.
    2. Disconnect the connector from the crankshaft position sensor.
    3. Turn the ignition switch to ON.
    4. Measure the voltage between crankshaft position sensor connector and engine ground.

      Connector & terminal 

      (E10) No. 1 (+) - Engine ground (-):

    Is the voltage 10 V or more?

    Yes:  Go to  118.

    No:  Repair the power supply circuit.

  118. CHECK HARNESS BETWEEN ECM AND CRANKSHAFT POSITION SENSOR CONNECTOR. 
    1. Turn the ignition switch to OFF.
    2. Disconnect the connector from ECM.
    3. Measure the resistance of harness between ECM connector and crankshaft position sensor connector.

      Connector & terminal 

      (E158) No. 19 - (E10) No. 2:

      (E158) No. 31 - (E10) No. 3:

    Is the resistance less than 1 Ω?

    Yes:  Go to  119.

    No:  Repair the open circuit in the harness between the ECM connector and crankshaft position sensor connector.

  119. CHECK HARNESS BETWEEN ECM AND CRANKSHAFT POSITION SENSOR CONNECTOR. 

    Measure the resistance between crankshaft position sensor connector and engine ground.

    Connector & terminal 

    (E10) No. 2 - Engine ground:

    Is the resistance 1 MΩ or more?

    Yes:  Go to  120.

    No:  Repair short circuit to ground in harness between ECM connector and crankshaft position sensor connector.

  120. CHECK COMPRESSION PRESSURE. 

    Check the compression pressure. Refer to MECHANICAL (EXCEPT FOR STI)>COMPRESSION>INSPECTION .

    Is the check result OK?

    Yes:  Go to  121.

    No:  Check the engine. Refer to MECHANICAL (EXCEPT FOR STI)>SYMPTOMS AND CAUSES>INSPECTION .

  121. CHECK FOR MALFUNCTION OCCURRENCE. 
    1. Replace the crankshaft position sensor. Refer to FUEL INJECTION (FUEL SYSTEMS) (EXCEPT FOR STI)>CRANKSHAFT POSITION SENSOR .
    2. Check that the fault is removed.

    Is the fault removed?

    Yes:  Perform the Clear Memory Mode to complete. Refer to ENGINE (DIAGNOSTICS) (EXCEPT FOR STI)>CLEAR MEMORY MODE .

    No:  Check the valve timing. Refer to MECHANICAL (EXCEPT FOR STI)>TIMING CHAIN ASSEMBLY . When the valve timing is normal, replace the ECM. Refer to FUEL INJECTION (FUEL SYSTEMS) (EXCEPT FOR STI)>ENGINE CONTROL MODULE (ECM) .

  122. CHECK OF FUEL PUMP. 

    Check fuel pump. Refer to FUEL INJECTION (FUEL SYSTEMS) (EXCEPT FOR STI)>FUEL PUMP>INSPECTION .

    Is the check result OK?

    Yes:  Check fuel pump system. Refer to ENGINE (DIAGNOSTICS) (EXCEPT FOR STI)>DIAGNOSTIC PROCEDURE WITH DIAGNOSTIC TROUBLE CODE (DTC)>DTC P0230 FUEL PUMP PRIMARY CIRCUIT .

    No:  Replace the fuel pump. Refer to FUEL INJECTION (FUEL SYSTEMS) (EXCEPT FOR STI)>FUEL PUMP .

  123. CHECK FUEL PRESSURE. 
    WARNING: Place "NO OPEN FLAMES" signs near the working area.
    CAUTION:
    • Be careful not to spill fuel.
    • Before attaching/detaching a fuel pressure gauge, release the fuel pressure.

    Measure the fuel pressure during cranking and five minutes after the engine is stopped. Refer to MECHANICAL (EXCEPT FOR STI)>FUEL PRESSURE>INSPECTION .

    Is the value of the fuel pressure during cranking 304 - 353 kPa (3.1 - 3.6 kgf/cm2 , 44 - 51 psi), and is the fuel pressure five minutes after engine stop 147 kPa (1.5 kgf/cm2 , 21 psi) or more?

    Yes:  Go to  124.

    No:  Go to  131.

  124. CHECK CURRENT DATA. 
    1. Turn the ignition switch to ON. (Engine OFF)
    2. Read the value of «Long term fuel trim B1» using the Subaru Select Monitor.
    NOTE: For detailed operation procedures, refer to "Current Data Display For Engine". Refer to ENGINE (DIAGNOSTICS) (EXCEPT FOR STI)>SUBARU SELECT MONITOR>OPERATION>DISPLAY CURRENT ENGINE DATA .

    Does the value of «Long term fuel trim B1» fall within a range of -15 - 15%?

    Yes:  Go to  125.

    No:  Replace the fuel injector. Refer to FUEL INJECTION (FUEL SYSTEMS) (EXCEPT FOR STI)>FUEL INJECTOR .

  125. CHECK FOR MALFUNCTION OCCURRENCE. 

    Start the engine and check the idling speed.

    Is the idling speed stable all time?

    Yes:  It is possible that the fault comes from fuel. Replace fuel.

    No:  Go to  126.

  126. CHECK INSTALLATION CONDITION OF CRANKSHAFT POSITION SENSOR. 

    Check installation condition of the crankshaft position sensor.

    Is the crankshaft position sensor installed correctly?

    Yes:  Go to  127.

    No:  Install the crankshaft position sensor correctly. Refer to FUEL INJECTION (FUEL SYSTEMS) (EXCEPT FOR STI)>CRANKSHAFT POSITION SENSOR>INSTALLATION .

  127. CHECK POWER SUPPLY TO CRANKSHAFT POSITION SENSOR. 
    1. Turn the ignition switch to OFF.
    2. Disconnect the connector from the crankshaft position sensor.
    3. Turn the ignition switch to ON.
    4. Measure the voltage between crankshaft position sensor connector and engine ground.

      Connector & terminal 

      (E10) No. 1 (+) - Engine ground (-):

    Is the voltage 10 V or more?

    Yes:  Go to  128.

    No:  Repair the power supply circuit.

  128. CHECK HARNESS BETWEEN ECM AND CRANKSHAFT POSITION SENSOR CONNECTOR. 
    1. Turn the ignition switch to OFF.
    2. Disconnect the connector from ECM.
    3. Measure the resistance of harness between ECM connector and crankshaft position sensor connector.

      Connector & terminal 

      (E158) No. 19 - (E10) No. 2:

      (E158) No. 31 - (E10) No. 3:

    Is the resistance less than 1 Ω?

    Yes:  Go to  129.

    No:  Repair the open circuit in the harness between the ECM connector and crankshaft position sensor connector.

  129. CHECK HARNESS BETWEEN ECM AND CRANKSHAFT POSITION SENSOR CONNECTOR. 

    Measure the resistance between crankshaft position sensor connector and engine ground.

    Connector & terminal 

    (E10) No. 2 - Engine ground:

    Is the resistance 1 MΩ or more?

    Yes:  Go to  130.

    No:  Repair short circuit to ground in harness between ECM connector and crankshaft position sensor connector.

  130. CHECK FOR MALFUNCTION OCCURRENCE. 
    1. Replace the crankshaft position sensor. Refer to FUEL INJECTION (FUEL SYSTEMS) (EXCEPT FOR STI)>CRANKSHAFT POSITION SENSOR .
    2. Check that the fault is removed.

    Is the fault removed?

    Yes:  Perform the Clear Memory Mode to complete. Refer to ENGINE (DIAGNOSTICS) (EXCEPT FOR STI)>CLEAR MEMORY MODE .

    No:  Replace the ECM. Refer to FUEL INJECTION (FUEL SYSTEMS) (EXCEPT FOR STI)>ENGINE CONTROL MODULE (ECM) .

  131. CHECK OF FUEL PUMP. 

    Check fuel pump. Refer to FUEL INJECTION (FUEL SYSTEMS) (EXCEPT FOR STI)>FUEL PUMP>INSPECTION .

    Is the check result OK?

    Yes:  Go to  132.

    No:  Replace the fuel pump. Refer to FUEL INJECTION (FUEL SYSTEMS) (EXCEPT FOR STI)>FUEL PUMP .

  132. CHECK FUEL PUMP SYSTEM. 

    Check fuel pump system. Refer to ENGINE (DIAGNOSTICS) (EXCEPT FOR STI)>DIAGNOSTIC PROCEDURE WITH DIAGNOSTIC TROUBLE CODE (DTC)>DTC P0230 FUEL PUMP PRIMARY CIRCUIT .

    Is the check result OK?

    Yes:  Go to  133.

    No:  Repair the fuel pump system. Refer to ENGINE (DIAGNOSTICS) (EXCEPT FOR STI)>DIAGNOSTIC PROCEDURE WITH DIAGNOSTIC TROUBLE CODE (DTC)>DTC P0230 FUEL PUMP PRIMARY CIRCUIT .

  133. CHECK PURGE CONTROL SOLENOID VALVE. 

    Check purge control solenoid valve 1 and purge control solenoid valve 2. Refer to EMISSION CONTROL (AUX. EMISSION CONTROL DEVICES) (EXCEPT FOR STI)>PURGE CONTROL SOLENOID VALVE>INSPECTION .

    Is the check result OK?

    Yes:  Go to  134.

    No:  Replace the faulty purge control solenoid valve. Refer to EMISSION CONTROL (AUX. EMISSION CONTROL DEVICES) (EXCEPT FOR STI)>PURGE CONTROL SOLENOID VALVE .

  134. CHECK FUEL INJECTOR. 
    1. After the engine is stopped, scavenge inside of the intake manifold by applying compressed air.
    2. Measure the HC concentration inside the intake manifold 15 minutes after scavenging is completed.

    Is the HC concentration less than 4, 000 ppm?

    Yes:  Go to  135.

    No:  Replace the fuel injector. Refer to FUEL INJECTION (FUEL SYSTEMS) (EXCEPT FOR STI)>FUEL INJECTOR .

  135. CHECK INTAKE VALVE. 

    Check the intake valve. Refer to MECHANICAL (EXCEPT FOR STI)>CYLINDER HEAD>INSPECTION .

    Is there any deposit in the intake valve?

    Yes:  Clean the intake valve. Refer to MECHANICAL (EXCEPT FOR STI)>CYLINDER HEAD .

    No:  Go to  136.

  136. CHECK ENGINE COOLANT TEMPERATURE SENSOR. 

    Check the engine coolant temperature sensor. Refer to FUEL INJECTION (FUEL SYSTEMS) (EXCEPT FOR STI)>ENGINE COOLANT TEMPERATURE SENSOR>INSPECTION .

    Is the check result OK?

    Yes:  Go to  137.

    No:  Replace the engine coolant temperature sensor. Refer to FUEL INJECTION (FUEL SYSTEMS) (EXCEPT FOR STI)>ENGINE COOLANT TEMPERATURE SENSOR .

  137. CHECK INSTALLATION CONDITION OF CRANKSHAFT POSITION SENSOR. 

    Check installation condition of the crankshaft position sensor.

    Is the crankshaft position sensor installed correctly?

    Yes:  Go to  138.

    No:  Install the crankshaft position sensor correctly. Refer to FUEL INJECTION (FUEL SYSTEMS) (EXCEPT FOR STI)>CRANKSHAFT POSITION SENSOR>INSTALLATION .

  138. CHECK INSTALLATION CONDITION OF CAMSHAFT POSITION SENSOR. 

    Check installation condition of the camshaft position sensor.

    Is the camshaft position sensor installed correctly?

    Yes:  Go to  139.

    No:  Install the camshaft position sensor correctly. Refer to FUEL INJECTION (FUEL SYSTEMS) (EXCEPT FOR STI)>CAMSHAFT POSITION SENSOR>INSTALLATION .

  139. CHECK POWER SUPPLY TO CRANKSHAFT POSITION SENSOR. 
    1. Turn the ignition switch to OFF.
    2. Disconnect the connector from the crankshaft position sensor.
    3. Turn the ignition switch to ON.
    4. Measure the voltage between crankshaft position sensor connector and engine ground.

      Connector & terminal 

      (E10) No. 1 (+) - Engine ground (-):

    Is the voltage 10 V or more?

    Yes:  Go to  140.

    No:  Repair the power supply circuit.

  140. CHECK HARNESS BETWEEN ECM AND CRANKSHAFT POSITION SENSOR CONNECTOR. 
    1. Turn the ignition switch to OFF.
    2. Disconnect the connector from ECM.
    3. Measure the resistance of harness between ECM connector and crankshaft position sensor connector.

      Connector & terminal 

      (E158) No. 19 - (E10) No. 2:

      (E158) No. 31 - (E10) No. 3:

    Is the resistance less than 1 Ω?

    Yes:  Go to  141.

    No:  Repair the open circuit in the harness between the ECM connector and crankshaft position sensor connector.

  141. CHECK HARNESS BETWEEN ECM AND CRANKSHAFT POSITION SENSOR CONNECTOR. 

    Measure the resistance between crankshaft position sensor connector and engine ground.

    Connector & terminal 

    (E10) No. 2 - Engine ground:

    Is the resistance 1 MΩ or more?

    Yes:  Go to  142.

    No:  Repair short circuit to ground in harness between ECM connector and crankshaft position sensor connector.

  142. CHECK POWER SUPPLY OF INTAKE CAMSHAFT POSITION SENSOR. 
    1. Turn the ignition switch to OFF.
    2. Disconnect the connector from the intake camshaft position sensor.
    3. Turn the ignition switch to ON.
    4. Measure the voltage between intake camshaft position sensor connector and engine ground.

      Connector & terminal 

      (E35) No. 1 (+) - Engine ground (-):

      (E36) No. 1 (+) - Engine ground (-):

    Is the voltage 10 V or more?

    Yes:  Go to  143.

    No:  Repair the harness and connector.

    NOTE: In this case, repair the following item:
    • Open circuit or short circuit to ground in harness between main relay connector and intake camshaft position sensor connector
    • Poor contact of coupling connector
  143. CHECK HARNESS BETWEEN ECM AND INTAKE CAMSHAFT POSITION SENSOR CONNECTOR. 
    1. Turn the ignition switch to OFF.
    2. Disconnect the connector from ECM.
    3. Measure the resistance between ECM connector and intake camshaft position sensor connector.

      Connector & terminal 

      (E158) No. 21 - (E35) No. 2:

      (E158) No. 34 - (E35) No. 3:

      (E158) No. 20 - (E36) No. 2:

      (E158) No. 34 - (E36) No. 3:

    Is the resistance less than 1 Ω?

    Yes:  Go to  144.

    No:  Repair the open circuit in the harness between ECM connector and intake camshaft position sensor connector.

  144. CHECK HARNESS BETWEEN ECM AND INTAKE CAMSHAFT POSITION SENSOR CONNECTOR. 

    Measure the resistance between intake camshaft position sensor connector and engine ground.

    Connector & terminal 

    (E35) No. 2 - Engine ground:

    (E36) No. 2 - Engine ground:

    Is the resistance 1 MΩ or more?

    Yes:  Go to  145.

    No:  Repair short circuit to ground in the harness between ECM connector and intake camshaft position sensor connector.

  145. CHECK POWER SUPPLY OF EXHAUST CAMSHAFT POSITION SENSOR. 
    1. Turn the ignition switch to OFF.
    2. Disconnect the connector from the exhaust camshaft position sensor.
    3. Turn the ignition switch to ON.
    4. Measure the voltage between exhaust camshaft position sensor connector and engine ground.

      Connector & terminal 

      (E62) No. 1 (+) - Engine ground (-):

      (E65) No. 1 (+) - Engine ground (-):

    Is the voltage 10 V or more?

    Yes:  Go to  146.

    No:  Repair the harness and connector.

    NOTE: In this case, repair the following item:
    • Open circuit in harness between main relay and exhaust camshaft position sensor connector
    • Poor contact of coupling connector
  146. CHECK HARNESS BETWEEN ECM AND EXHAUST CAMSHAFT POSITION SENSOR CONNECTOR. 
    1. Turn the ignition switch to OFF.
    2. Disconnect the connector from ECM.
    3. Measure the resistance between ECM connector and exhaust camshaft position sensor connector.

      Connector & terminal 

      (E158) No. 32 - (E62) No. 2:

      (E158) No. 34 - (E62) No. 3:

      (E158) No. 33 - (E65) No. 2:

      (E158) No. 34 - (E65) No. 3:

    Is the resistance less than 1 Ω?

    Yes:  Go to  147.

    No:  Repair the open circuit in the harness between ECM connector and exhaust camshaft position sensor connector.

  147. CHECK HARNESS BETWEEN ECM AND EXHAUST CAMSHAFT POSITION SENSOR CONNECTOR. 

    Measure the resistance between exhaust camshaft position sensor connector and engine ground.

    Connector & terminal 

    (E62) No. 2 - Engine ground:

    (E65) No. 2 - Engine ground:

    Is the resistance 1 MΩ or more?

    Yes:  Go to  148.

    No:  Repair short circuit to ground in the harness between ECM connector and exhaust camshaft position sensor connector.

  148. CHECK COMPRESSION PRESSURE. 

    Check the compression pressure. Refer to MECHANICAL (EXCEPT FOR STI)>COMPRESSION>INSPECTION .

    Is the check result OK?

    Yes:  Go to  149.

    No:  Check the engine. Refer to MECHANICAL (EXCEPT FOR STI)>SYMPTOMS AND CAUSES>INSPECTION .

  149. CHECK FOR MALFUNCTION OCCURRENCE. 
    1. Replace the crankshaft position sensor. Refer to FUEL INJECTION (FUEL SYSTEMS) (EXCEPT FOR STI)>CRANKSHAFT POSITION SENSOR .
    2. Check that the fault is removed.

    Is the fault removed?

    Yes:  Perform the Clear Memory Mode to complete. Refer to ENGINE (DIAGNOSTICS) (EXCEPT FOR STI)>CLEAR MEMORY MODE .

    No:  Go to  150.

  150. CHECK FOR MALFUNCTION OCCURRENCE. 
    1. Replace the camshaft position sensor. Refer to FUEL INJECTION (FUEL SYSTEMS) (EXCEPT FOR STI)>CAMSHAFT POSITION SENSOR .
    2. Check that the fault is removed.

    Is the fault removed?

    Yes:  Perform the Clear Memory Mode to complete. Refer to ENGINE (DIAGNOSTICS) (EXCEPT FOR STI)>CLEAR MEMORY MODE .

    No:  Check the valve timing. Refer to MECHANICAL (EXCEPT FOR STI)>TIMING CHAIN ASSEMBLY . When the valve timing is normal, replace the ECM. Refer to FUEL INJECTION (FUEL SYSTEMS) (EXCEPT FOR STI)>ENGINE CONTROL MODULE (ECM) .

scientia non olet · About LEMON Manuals