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Diagnostic Procedure

  1. 8E1: CHECK ENGINE GROUND TERMINALS. 

    CHECK: Have engine ground terminals been tightened? 

    1. YES:  Go to step 8E2. 
    2. NO:  Tighten engine ground terminals.
  2. 8E2: CHECK THROTTLE POSITION SENSOR. 
    1. Turn ignition switch to OFF.
    2. Disconnect connector from throttle position sensor.
    3. Measuring resistance between throttle position sensor connector receptacle's terminals.

    Terminals 

    No. 4 - No. 2: 

    Fig 1: Measuring Resistance Between Throttle Position Sensor Connector Receptacle's Terminals
    G02003491

    CHECK: Is the resistance between 0.3 and 0.7 kohm? 

    1. YES:  Go to step 8E3. 
    2. NO:  Replace throttle position sensor, see THROTTLE POSITION SENSOR  .
  3. 8E3: CHECK THROTTLE POSITION SENSOR. 

    Measuring resistance between throttle position sensor connector receptacle's terminals.

    Terminals 

    No. 2 - No. 3: 

    Fig 2: Measuring Resistance Between Throttle Position Sensor Connector Receptacle's Terminals
    G02003492

    CHECK: Is the resistance between 3.5 and 6.5 kohm? 

    1. YES:  Go to step 8E4. 
    2. NO:  Replace throttle position sensor, see THROTTLE POSITION SENSOR  .
  4. 8E4: CHECK HARNESS CONNECTOR BETEEN TCM AND THROTTLE POSITION SENSOR. 

    Measuring resistance of harness between TCM and throttle position sensor connector.

    Connector & Terminal 

    (B55) No. 2 - (E13) No. 3: 

    Fig 3: Measuring Resistance Of Harness Between TCM & Throttle Position Sensor Connector
    G02003493

    CHECK: Is the resistance less than 1 ohm? 

    1. YES:  Go to step 8E5. 
    2. NO:  Repair open circuit in harness between TCM and throttle position sensor connector.
  5. 8E5: CHECK HARNESS CONNECTOR BETWEEN TCM AND THROTTLE POSITION SENSOR. 

    Measuring resistance of harness between TCM and throttle position sensor connector.

    Connector & Terminal 

    (B55) No. 1 - (E13) No. 4: 

    Fig 4: Measuring Resistance Of Harness Between TCM & Throttle Position Sensor Connector
    G02003494

    CHECK: Is the resistance less than 1 ohm? 

    1. YES:  Go to step 8E6. 
    2. NO:  Repair open circuit in harness between TCM and throttle position sensor connector.
  6. 8E6: CHECK HARNESS CONNECTOR BETWEEN TCM AND THROTTLE POSITION SENSOR. 

    Measuring resistance of harness between TCM connector and chassis ground.

    Connector & Terminal 

    (B55) No. 2 - Chassis ground: 

    Fig 5: Measuring Resistance Of Harness Between TCM Connector & Chassis Ground
    G02003495

    CHECK: Is the resistance more than 1 Mohm? 

    1. YES:  Go to step 8E7. 
    2. NO:  Repair short circuit in harness between TCM and throttle position sensor connector.
  7. 8E7: CHECK HARNESS CONNECTOR BETWEEN TCM AND THROTTLE POSITION SENSOR. 

    Measure resistance of harness between TCM connector and chassis ground.

    Connector & Terminal 

    (B55) No. 1 - Chassis ground: 

    Fig 6: Measuring Resistance Of Harness Between TCM Connector & Chassis Ground
    G02003496

    CHECK: Is the resistance more than 1 Mohm? 

    1. YES:  Go to step 8E8. 
    2. NO:  Repair short circuit in harness between TCM and throttle position sensor connector.
  8. 8E8: PREPARE SUBARU SELECT MONITOR. 

    CHECK: Do you have a Subaru Select Monitor? 

    1. YES:  Go to step  8E11 .
    2. NO:  Go to step 8E9. 
  9. 8E9: CHECK INPUT SIGNAL FOR TCM. 
    1. Connect connector to throttle position sensor.
    2. Turn ignition switch to ON (engine OFF).
    3. Measure voltage between TCM connector terminals.

    Connector & Terminal 

    (B55) No. 2 (+) - No. 9 (-): 

    Fig 7: Measuring Voltage Between TCM Connector Terminals
    G02003497

    CHECK: Is the voltage between 0.3 and 0.7 V in throttle fully closed? 

    1. YES:  Go to step 8E10. 
    2. NO:  Go to step  8E15.
  10. 8E10: CHECK INPUT SIGNAL FOR TCM. 

    Measure voltage between TCM connector terminals.

    Connector & Terminal 

    (B55) No. 2 (+) - No. 9 (-): 

    Fig 8: Measuring Voltage Between TCM Connector Terminals
    G02003498

    CHECK: Is the voltage between 4.3 and 4.9 V in throttle fully open? 

    1. YES:  Go to step  8E13.
    2. NO:  Go to step  8E15.
  11. 8E11: CHECK INPUT SIGNAL FOR TCM USING SUBARU SELECT MONITOR. 
    1. Connect connectors to throttle position sensor.
    2. Connect Subaru Select Monitor to data link connector.
      Fig 9: Identifying Location Data Link Connector (DLC)
      G02003499
    3. Turn ignition switch to ON (engine OFF).
    4. Turn Subaru Select Monitor switch to ON.
    5. Throttle fully closed.
    6. Read data of throttle position sensor using Subaru Select Monitor.
    • Throttle position sensor input signal is indicated.

    CHECK Is the value voltage between 0.3 and 0.7 V? 

    1. YES:  Go to step 8E12. 
    2. NO:  Go to step  8E15.
  12. 8E12: CHECK INPUT SIGNAL FOR TCM USING SUBARU SELECT MONITOR. 

    Throttle fully open.

    NOTE: Must be changed correspondingly with accelerator pedal operation (from "released" to "depressed" position).

    CHECK: Is the value voltage between 4.3 and 4.9 V? 

    1. YES:  Go to step  8E14.
    2. NO:  Go to step  8E15.
  13. 8E13: CHECK INPUT SIGNAL FOR TCM (THROTTLE POSITION SENSOR POWER SUPPLY). 

    Measure voltage between TCM connector and chassis ground.

    Connector & Terminal 

    (B55) No. 1 (+) - Chassis ground (-): 

    Fig 10: Measuring Voltage Between TCM Connector & Chassis Ground
    G02003500

    CHECK: Is the voltage between 4.8 and 5.3 V? 

    1. YES:  Even if "AT OIL TEMP" lights up, the circuit has returned to a normal condition at this time. A temporary poor contact of the connector or harness may be the cause. Repair harness or connector in throttle position sensor circuit.
    2. NO:  Go to step  8E15.
  14. 8E14: CHECK INPUT SIGNAL FOR TCM USING SUBARU SELECT MONITOR (THROTTLE POSITION SENSOR POWER SUPPLY). 

    Read data of throttle position sensor power supply using Subaru Select Monitor.

    • Throttle position sensor power supply voltage is indicated.

    CHECK: Is the value voltage between 4.8 and 5.3 V? 

    1. YES:  Even if "AT OIL TEMP" lights up, the circuit has returned to a normal condition at this time. A temporary poor contact of the connector or harness may be the cause. Repair harness or connector in throttle position sensor circuit.
    2. NO:  Go to step 8E15. 
  15. 8E15: CHECK POOR CONTACT. 

    CHECK: Is there poor contact in throttle position sensor circuit? 

    1. YES:  Repair poor contact.
    2. NO:  Replace TCM, see TRANSMISSION CONTROL MODULE (TCM) .
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