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Home >> Infiniti >> 2010 >> M45 Base >> Repair and Diagnosis >> Engine Performance >> System >> Engine Control System - Component Testing >> Ignition Signal >> Diagnosis Procedure
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Diagnosis 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. Check 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 46, 60, 61, 62, 65, 79, 80, 81 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: [Voltage Signal Waveform]
    G06303512Courtesy of NISSAN MOTOR CO., U.S.A.
    Fig 2: Checking Voltage Signal Between ECM Terminals And Ground
    G06303513Courtesy 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 terminals 119, 120 and ground with CONSULT-III or tester.

    Voltage: Battery voltage 

    OK or NG 

    OK: GO TO 5.

    NG: Go to "DIAGNOSIS PROCEDURE ".

    Fig 3: Checking Voltage Between ECM Terminals 119, 120 And Ground
    G04900811Courtesy of NISSAN MOTOR CO., U.S.A.
  5. CHECK IGNITION COIL POWER SUPPLY CIRCUIT-II
    1. Turn ignition switch OFF.
    2. Disconnect condenser (1) harness connector.
    3. Turn ignition switch ON.
      Fig 4: Identifying Condenser Harness Connector
      G05211163Courtesy of NISSAN MOTOR CO., U.S.A.
    4. Check voltage between condenser terminal 1 and ground with CONSULT-III or tester.

    Voltage: Battery voltage 

    OK or NG 

    OK: GO TO  8.

    NG: GO TO 6.

    Fig 5: Checking Voltage Between Condenser Terminal 1 And Ground
    G04875485Courtesy of NISSAN MOTOR CO., U.S.A.
  6. CHECK IGNITION COIL POWER SUPPLY CIRCUIT-III
    1. Turn ignition switch OFF.
    2. Disconnect IPDM E/R harness connector E7.
    3. Check harness continuity between IPDM E/R terminal 17 and condenser terminal 1.

      Refer to SYSTEM WIRING DIAGRAMS article.

      Continuity should exist  .

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

    OK or NG 

    OK: Go to "DIAGNOSIS PROCEDURE ".

    NG: GO TO 7.

  7. DETECT MALFUNCTIONING PART

    Check the following.

    • Harness connectors E12, F3
    • Harness for open or short between IPDM E/R and condenser

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

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

      Refer to SYSTEM WIRING DIAGRAMS article.

      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

    Refer to "COMPONENT INSPECTION "

    OK or NG 

    OK: GO TO 10.

    NG: Replace condenser.

  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.
      Fig 6: Identifying Ignition Coil Harness Connector
      G06303517Courtesy of NISSAN MOTOR CO., U.S.A.
    4. Turn ignition switch ON.
    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 7: 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 F3
    • Harness for open or short between ignition coil and harness connector F3

    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 SYSTEM WIRING DIAGRAMS article.

      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 46, 60, 61, 62, 65, 79, 80, 81 and ignition coil terminal 1. Refer to SYSTEM WIRING DIAGRAMS article.

      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 "DIAGNOSIS PROCEDURE ".

    INSPECTION END 

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