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Home › Nissan-Datsun › 2005 › Xterra SE, 4WD › Repair and Diagnosis › Engine Performance › System › Engine Control System - Introduction › Power Supply And Ground Circuit › Diagnostic Procedure

Diagnostic Procedure

  1. INSPECTION START 

    Start engine.

    Is engine running? 

    Yes or No 

    1. Yes: GO TO  8.
    2. 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 109 and ground with CONSULT-II or tester.

      Voltage: Battery voltage 

    OK or NG 

    1. OK: GO TO  4.
    2. NG: GO TO 3.
      Fig 1: Checking Voltage Between ECM Terminal 109 And Ground
      G03606766Courtesy of NISSAN MOTOR CO., U.S.A.
  3. DETECT MALFUNCTIONING PART 

    Check the following.

    • Harness connectors M31, E152
    • Fuse block (J/B) connector M4
    • 10A fuse
    • Harness for open or short between ECM and fuse
    1. : Repair harness or connectors.
  4. CHECK GROUND CONNECTIONS 
    1. Turn ignition switch OFF.
    2. Loosen and retighten three ground screws on the body. Refer to "GROUND INSPECTION ".
      Fig 2: Checking Ground Connections
      G03606767Courtesy of NISSAN MOTOR CO., U.S.A.

    OK or NG 

    1. OK: GO TO 5.
    2. 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 1, 115, 116 and ground. Refer to Wiring Diagram .

      Continuity should exist  .

    3. Also check harness for short to power.

    OK or NG 

    1. OK: GO TO  7.
    2. NG: GO TO 6.
  6. DETECT MALFUNCTIONING PART 

    Check the following.

    • Harness connectors F32, E2
    • Harness for open or short between ECM and ground
    1. : 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 connector E119 terminal 3 and ground with CONSULT-II or tester.

      Voltage: Battery voltage 

    OK or NG 

    1. OK: Go to "IGNITION SIGNAL ".
    2. NG: GO TO 8.
      Fig 3: Checking Voltage Between IPDM E/R Connector E119 Terminal 3 And Ground
      G03606768Courtesy of NISSAN MOTOR CO., U.S.A.
  8. CHECK ECM POWER SUPPLY CIRCUIT-III 
    1. Turn ignition switch ON and then OFF.
    2. Check voltage between ECM terminals 119, 120 and ground with CONSULT-II or tester.

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

    OK or NG 

    1. OK: GO TO  13.
    2. NG (Battery voltage does not exist.): GO TO 9.
    3. NG (Battery voltage exists for more than a few seconds.): GO TO  11.
      Fig 4: Checking Voltage Between ECM Terminals 119, 120 And Ground
      G03606769Courtesy of NISSAN MOTOR CO., U.S.A.
  9. CHECK ECM POWER SUPPLY CIRCUIT-IV 
    1. Turn ignition switch OFF, and wait at least 10 seconds.
    2. Check voltage between ECM terminal 111 and ground with CONSULT-II or tester.

    Voltage: Battery voltage 

    OK or NG 

    1. OK: GO TO 10.
    2. NG: GO TO  11.
      Fig 5: Checking Voltage Between ECM Terminal 111 And Ground
      G03606770Courtesy 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 E119.
    3. Check harness continuity between ECM terminals 119, 120 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 

    1. OK: GO TO  16.
    2. 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 E119.
    3. Check harness continuity between ECM terminal 111 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 

    1. OK: GO TO 12.
    2. NG: Repair open circuit or short to ground or short to power in harness or connectors.
  12. CHECK 20A FUSE 
    1. Disconnect 20 A fuse from IPDM E/R.
    2. Check 20A fuse.

    OK or NG 

    1. OK: GO TO  16.
    2. NG: Replace 20A fuse.
  13. CHECK GROUND CONNECTIONS 

    Loosen and retighten three ground screws on the body. Refer to "GROUND INSPECTION ".

    Fig 6: Checking Ground Connections
    G03606771Courtesy of NISSAN MOTOR CO., U.S.A.

    OK or NG 

    1. OK: GO TO 14.
    2. NG: Repair or replace ground connections.
  14. CHECK ECM GROUND CIRCUIT FOR OPEN AND SHORT-II 
    1. Check harness continuity between ECM terminals 1, 115, 116 and ground. Refer to Wiring Diagram .

      Continuity should exist  .

    2. Also check harness for short to power.

    OK or NG 

    1. OK: GO TO  16.
    2. NG: GO TO 15.
  15. DETECT MALFUNCTIONING PART 

    Check the following.

    • Harness connectors F32, E2
    • Harness for open or short between ECM and ground
    1. : Repair open circuit or short to power in harness or connectors.
  16. CHECK INTERMITTENT INCIDENT 

    Refer to "TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT ".

    OK or NG 

    1. OK: Replace IPDM E/R.
    2. NG: Repair open circuit or short to power in harness or connectors.
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