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Home >> Nissan-Datsun >> 2008 >> Sentra SE-R >> Repair and Diagnosis >> Engine Performance >> Engine Control Systems >> Engine Control System - Introduction (Qr25DE) >> Power Supply And Ground Circuit >> Diagnostic Procedure
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Diagnostic Procedure

  1. INSPECTION START 

    Start engine.

    Is engine running? 

    Yes or No 

    Yes: GO TO  8.

    No: GO TO 2.

  2. CHECK ECM POWER SUPPLY CIRCUIT-I 
    1. Turn ignition switch OFF and then ON.
    2. Check voltage between ECM terminal 93 and ground with CONSULT-III or tester.

      Voltage: Battery voltage 

    OK or NG 

    OK: GO TO  4.

    NG: GO TO 3.

    Fig 1: Checking Voltage Between ECM Terminal 93 And Ground
    G04925190Courtesy of NISSAN MOTOR CO., U.S.A.
  3. DETECT MALFUNCTIONING PART 

    Check the following.

    • Harness connectors M6, E19
    • Harness for open or short between ECM and ignition switch

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

  4. CHECK GROUND CONNECTIONS 
    1. Turn ignition switch OFF.
    2. Loosen and retighten ground screws on the body.

      Refer to "GROUND INSPECTION ".

      Fig 2: Identifying Body Ground Connections
      G04925786Courtesy of NISSAN MOTOR CO., U.S.A.

    OK or NG 

    OK: GO TO 5.

    NG: Repair or replace ground connections.

  5. CHECK ECM GROUND CIRCUIT FOR OPEN AND SHORT-I 
    1. Disconnect ECM harness connector.
    2. Check harness continuity between ECM terminals 12, 16, 107, 108, 111, 112 and ground.

      Refer to WIRING DIAGRAM .

      Continuity should exist. 

    3. Also check harness for short to power.

    OK or NG 

    OK: GO TO  7.

    NG: GO TO 6.

  6. DETECT MALFUNCTIONING PART 

    Check the following.

    • Harness connectors F10, E17
    • Harness for open or short between ECM and ground

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

  7. CHECK ECM POWER SUPPLY CIRCUIT-II 
    1. Reconnect ECM harness connector.
    2. Turn ignition switch ON.
    3. Check voltage between IPDM E/R terminal 3 and ground with CONSULT-III or tester.

      Voltage: Battery voltage 

    OK or NG 

    OK: Go to "IGNITION SIGNAL ".

    NG: GO TO 8.

    Fig 3: Checking Voltage Between IPDM E/R Terminal 3 And Ground
    G04894575Courtesy of NISSAN MOTOR CO., U.S.A.
  8. CHECK ECM POWER SUPPLY CIRCUIT-III 
    1. Turn ignition switch OFF and wait at least 10 seconds.
    2. Turn ignition switch ON and then OFF.
    3. Check voltage between ECM terminal 105 and ground with CONSULT-III or tester.

      Voltage: After turning ignition switch OFF, battery voltage will exist for a few seconds, then drop approximately 0V. 

      Fig 4: Checking Voltage Between ECM Terminal 105 And Ground
      G04925193Courtesy of NISSAN MOTOR CO., U.S.A.

    OK or NG 

    OK: GO TO  14.

    NG (Battery voltage does not exist.): GO TO 9.

    NG (Battery voltage exists for more than a few seconds.): GO TO  11.

  9. CHECK ECM POWER SUPPLY CIRCUIT-IV 
    1. Turn ignition switch OFF and wait at least 10 seconds.
    2. Check voltage between ECM terminal 24 and ground with CONSULT-III or tester.

      Voltage: Battery voltage 

    OK or NG 

    OK: GO TO 10.

    NG: GO TO  11.

    Fig 5: Checking Voltage Between ECM Terminal 24 And Ground
    G04925789Courtesy of NISSAN MOTOR CO., U.S.A.
  10. CHECK ECM POWER SUPPLY CIRCUIT-V 
    1. Disconnect ECM harness connector.
    2. Disconnect IPDM E/R harness connector E43.
    3. Check harness continuity between ECM terminal 105 and IPDM E/R terminal 4.

      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  17.

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

  11. CHECK ECM POWER SUPPLY CIRCUIT-VI 
    1. Disconnect ECM harness connector.
    2. Disconnect IPDM E/R harness connector E43.
    3. Check harness continuity between ECM terminal 24 and IPDM E/R terminal 7.

      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  13.

    NG: GO TO 12.

  12. DETECT MALFUNCTIONING PART 

    Check the following.

    • Harness connectors E3, F2
    • Harness for open or short between ECM and IPDM E/R

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

  13. CHECK 20A FUSE 
    1. Disconnect 20A fuse from IPDM E/R.
    2. Check 20A fuse.

    OK or NG 

    OK: GO TO  17.

    NG: Replace 20A fuse.

  14. CHECK GROUND CONNECTIONS 

    Loosen and retighten ground screws on the body.

    Refer to "GROUND INSPECTION ".

    Fig 6: Identifying Body Ground Connections
    G04925790Courtesy of NISSAN MOTOR CO., U.S.A.

    OK or NG 

    OK: GO TO 15.

    NG: Repair or replace ground connections.

  15. CHECK ECM GROUND CIRCUIT FOR OPEN AND SHORT-II 
    1. Disconnect ECM harness connector.
    2. Check harness continuity between ECM terminals 12, 16, 107, 108, 111, 112 and ground.

      Refer to WIRING DIAGRAM .

      Continuity should exist. 

    3. Also check harness for short to power.

    OK or NG 

    OK: GO TO  17.

    NG: GO TO 16.

  16. DETECT MALFUNCTIONING PART 

    Check the following.

    • Harness connectors F10, E17
    • Harness for open or short between ECM and ground

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

  17. CHECK INTERMITTENT INCIDENT 

    Refer to "TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT ".

    OK or NG 

    OK: Replace IPDM E/R. Refer to "IPDM E/R (INTELLIGENT POWER DISTRIBUTION MODULE ENGINE ROOM) ".

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

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