LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> Nissan-Datsun >> 2006 >> Quest Base >> Repair and Diagnosis >> Engine Performance >> System >> Engine Control System - Introduction >> Power Supply And Ground Circuit >> Diagnostic Procedure
April 5, 2026: LEMON Manuals is launched! Read the announcement.

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 109 and ground with CONSULT-II or tester.

      Voltage: Battery voltage 

    OK or NG 

    OK : GO TO  4.

    NG : GO TO 3.

    Fig 1: Checking Voltage Between ECM Terminal 109 And Ground
    G04196498Courtesy of NISSAN MOTOR CO., U.S.A.
  3. DETECT MALFUNCTIONING PART 

    Check the following.

    • Fuse block (J/B) connector E30
    • 10A fuse
    • Harness for open or short between ECM and fuse

      : 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: Locating Body Ground Screws E24, E15, F9 And E133
      G04196499Courtesy 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 1, 115, 116 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 F14, E5
    • 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 17 and ground with CONSULT-II 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 17 And Ground
    G04196500Courtesy 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 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 

    OK : GO TO  13.

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

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

    Fig 4: Checking Voltage Between ECM Terminals
    G04196501Courtesy 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 

    OK : GO TO 10.

    NG : GO TO  11.

    Fig 5: Checking Voltage Between ECM Terminal 111 And Ground
    G04196502Courtesy 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 E122.
    3. Check harness continuity between ECM terminals 119, 120 and IPDM E/R terminal 18. 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  16.

    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 E121.
    3. Check harness continuity between ECM terminal 111 and IPDM E/R terminal 46. 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  12.

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

  12. CHECK 15A FUSE 
    1. Disconnect 15A fuse from IPDM E/R.
    2. Check 15A fuse.

    OK or NG 

    OK : GO TO  16.

    NG : Replace 15A fuse.

  13. CHECK GROUND CONNECTIONS 

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

    Fig 6: Locating Body Ground Screws E24, E15, F9 And E133
    G04196499Courtesy of NISSAN MOTOR CO., U.S.A.

    OK or NG 

    OK : GO TO 14.

    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 

    OK : GO TO  16.

    NG : GO TO 15.

  15. DETECT MALFUNCTIONING PART 

    Check the following.

    • Harness connectors F14, E5
    • Harness for open or short between ECM and ground

      : 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 

    OK : Replace IPDM E/R.

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

scientia non olet · About LEMON Manuals