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Home >> Nissan-Datsun >> 2008 >> Sentra SE-R >> Repair and Diagnosis >> Engine Performance >> Engine Control Systems >> Engine Control System - Component Testing (Qr25DE) >> Ignition Signal >> Diagnostic Procedure
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Diagnostic Procedure

  1. CHECK ENGINE START 

    Turn ignition switch OFF, and restart engine.

    Is engine running? 

    Yes or No 

    Yes (With CONSULT-III): GO TO 2.

    Yes (Without CONSULT-III): GO TO  3.

    No: GO TO  4.

  2. CHECK OVERALL FUNCTION 

    With CONSULT-III 

    1. Perform "POWER BALANCE" in "ACTIVE TEST" mode with CONSULT-III.
    2. Make sure that each circuit produces a momentary engine speed drop.

    OK or NG 

    OK: INSPECTION END 

    NG: GO TO  10.

  3. CHECK OVERALL FUNCTION 

    Without CONSULT-III 

    1. Let engine idle.
    2. Read the voltage signal between ECM terminals 9, 10, 11, 21 and ground with an oscilloscope.
    3. Verify that the oscilloscope screen shows the signal wave as shown below.
      NOTE: The pulse cycle changes depending on RPM at idle.
      Fig 1: Identifying Signal Waveform
      G04926268Courtesy of NISSAN MOTOR CO., U.S.A.
      Fig 2: Checking Voltage Signal Between ECM Terminals 9, 10, 11, 21 And Ground
      G04926269Courtesy of NISSAN MOTOR CO., U.S.A.

    OK or NG 

    OK: INSPECTION END 

    NG: GO TO  10.

  4. CHECK IGNITION COIL POWER SUPPLY CIRCUIT-I 
    1. Turn ignition switch OFF, wait at least 10 seconds and then turn ON.
    2. Check voltage between ECM terminal 105 and ground with CONSULT-III or tester.

      Voltage: Battery voltage 

      Fig 3: Checking Voltage Between ECM Terminal 105 And Ground
      G04925644Courtesy of NISSAN MOTOR CO., U.S.A.

    OK or NG 

    OK: GO TO 5.

    NG: Go to "POWER SUPPLY AND GROUND CIRCUIT ".

  5. CHECK IGNITION COIL POWER SUPPLY CIRCUIT-II 
    1. Turn ignition switch OFF.
    2. Disconnect condenser-2 harness connector.
    3. Turn ignition switch ON.
    4. Check voltage between condenser-2 terminal 1 and ground with CONSULT-III or tester.

      Voltage: Battery voltage 

      Fig 4: Checking Voltage Between Condenser-2 Terminal 1 And Ground
      G04875485Courtesy of NISSAN MOTOR CO., U.S.A.

    OK or NG 

    OK: GO TO  8.

    NG: GO TO 6.

  6. CHECK IGNITION COIL POWER SUPPLY CIRCUIT-III 
    1. Turn ignition switch OFF.
    2. Disconnect IPDM E/R harness connector E43.
    3. Check harness continuity between IPDM E/R terminal 3 and condenser-2 terminal 1.

      Refer to WIRING DIAGRAM .

      Continuity should exist. 

    4. Also check harness for short to ground and short to power.

    OK or NG 

    OK: Go to "POWER SUPPLY AND GROUND CIRCUIT ".

    NG: GO TO 7.

  7. DETECT MALFUNCTIONING PART 

    Check the following.

    • Harness connectors E17, F10
    • Harness for open or short between IPDM E/R and condenser-2

      : Repair open circuit or short to ground or short to power in harness or connectors.

  8. CHECK CONDENSER-2 GROUND CIRCUIT FOR OPEN AND SHORT 
    1. Turn ignition switch OFF.
    2. Check harness continuity between condenser-2 terminal 2 and ground.

      Refer to WIRING DIAGRAM .

      Continuity should exist. 

    3. Also check harness for short to power.

    OK or NG 

    OK: GO TO 9.

    NG: Repair open circuit or short to power in harness or connectors.

  9. CHECK CONDENSER-2 

    Refer to "COMPONENT INSPECTION "

    OK or NG 

    OK: GO TO 10.

    NG: Replace condenser-2.

  10. CHECK IGNITION COIL POWER SUPPLY CIRCUIT-IV 
    1. Turn ignition switch OFF.
    2. Reconnect all harness connectors disconnected.
    3. Disconnect ignition coil harness connector (1).
    4. Turn ignition switch ON.
      Fig 5: Identifying Ignition Coil Harness Connector
      G04926263Courtesy of NISSAN MOTOR CO., U.S.A.
    5. Check voltage between ignition coil terminal 3 and ground with CONSULT-III or tester.

      Voltage: Battery voltage 

    OK or NG 

    OK: GO TO  12.

    NG: GO TO 11.

    Fig 6: Checking Voltage Between Ignition Coil Terminal 3 And Ground
    G04875257Courtesy of NISSAN MOTOR CO., U.S.A.
  11. DETECT MALFUNCTIONING PART 

    Check the following.

    • Harness connector F10
    • Harness for open or short between ignition coil and harness connector F10

      : Repair or replace harness or connectors.

  12. CHECK IGNITION COIL GROUND CIRCUIT FOR OPEN AND SHORT 
    1. Turn ignition switch OFF.
    2. Check harness continuity between ignition coil terminal 2 and ground.

      Refer to WIRING DIAGRAM .

      Continuity should exist. 

    3. Also check harness for short to power.

    OK or NG 

    OK: GO TO 13.

    NG: Repair open circuit or short to power in harness or connectors.

  13. CHECK IGNITION COIL OUTPUT SIGNAL CIRCUIT FOR OPEN AND SHORT 
    1. Disconnect ECM harness connector.
    2. Check harness continuity between ECM terminals 9, 10, 11, 21 and ignition coil terminal 1.

      Refer to WIRING DIAGRAM .

      Continuity should exist. 

    3. Also check harness for short to ground and short to power.

    OK or NG 

    OK: GO TO 14.

    NG: Repair open circuit or short to ground or short to power in harness or connectors.

  14. CHECK IGNITION COIL WITH POWER TRANSISTOR 

    Refer to "COMPONENT INSPECTION ".

    OK or NG 

    OK: GO TO 15.

    NG: Replace malfunctioning ignition coil with power transistor.

  15. CHECK INTERMITTENT INCIDENT 

    Refer to "TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT ".

    : INSPECTION END 

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