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Home >> Nissan-Datsun >> 2006 >> Sentra Base, Standard >> Repair and Diagnosis >> Engine Performance >> System >> Engine Control System - Component Testing (QG18DE) >> Electrical Load Signal >> Diagnostic Procedure
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Diagnostic Procedure

  1. INSPECTION START 

    Do you have CONSULT-II?

    Yes or No 

    Yes: GO TO  2.

    No: GO TO  3.

  2. CHECK LOAD SIGNAL CIRCUIT OVERALL FUNCTION-I 

    With CONSULT-II 

    1. Turn ignition switch ON.
    2. Check "LOAD SIGNAL" in "DATA MONITOR" mode with CONSULT-II under the following conditions.
      3. Fig 1: Consult-II DATA MONITOR Display Screen
      G04075263Courtesy of NISSAN MOTOR CO., U.S.A.
    CONDITION AND LOAD SIGNAL REFERENCE

    Condition LOAD SIGNAL
    Lighting switch ON at 2nd position ON
    Lighting switch OFF OFF

    OK or NG 

    OK: GO TO  4.

    NG: GO TO  8.

  3. CHECK LOAD SIGNAL CIRCUIT OVERALL FUNCTION-I 

    Without CONSULT-II 

    1. Turn ignition switch ON.
    2. Check voltage between ECM terminal 84 and ground under the following conditions.
      3. Fig 2: Checking Voltage Between ECM Terminal 84 And Ground
      G04191460Courtesy of NISSAN MOTOR CO., U.S.A.
    TERMINALS VOLTAGE REFERENCE

    Condition Voltage
    Lighting switch ON at 2nd position BATTERY VOLTAGE
    Lighting switch OFF 0V

    OK or NG 

    OK: GO TO  5.

    NG: GO TO  8.

  4. CHECK LOAD SIGNAL CIRCUIT OVERALL FUNCTION-II 

    With CONSULT-II 

    1. Turn ignition switch ON.
    2. Check "HEATER FAN SW" in "DATA MONITOR" mode with CONSULT-II under the following conditions.
      3. Fig 3: CONSULT-II Display -- DATA MONITOR
      G04191461Courtesy of NISSAN MOTOR CO., U.S.A.
    CONDITION AND INDICATION REFERENCE (A/T MODELS)

    Condition INDICATION
    FAN control switch ON in any position ON
    FAN control switch OFF OFF

    OK or NG 

    OK: GO TO  6.

    NG: GO TO  13.

  5. CHECK LOAD SIGNAL CIRCUIT OVERALL FUNCTION-II 

    Without CONSULT-II 

    1. Turn ignition switch ON.
    2. Check voltage between ECM terminal 96 and ground under the following conditions.
    Fig 4: Checking Voltage Between ECM Terminal 96 And Ground
    G04191462Courtesy of NISSAN MOTOR CO., U.S.A.
    TERMINALS VOLTAGE REFERENCE

    Condition Voltage
    FAN control switch ON in any position Approximately 0V
    FAN control switch OFF Approximately 5V

    OK or NG 

    OK: GO TO  7.

    NG: GO TO  13.

  6. CHECK LOAD SIGNAL CIRCUIT OVERALL FUNCTION-III 

    With CONSULT-II 

    1. Turn ignition switch ON.
    2. Check "LOAD SIGNAL" in "DATA MONITOR" mode with CONSULT-II under the following conditions.
      3. Fig 5: Consult-II DATA MONITOR Display Screen
      G04075263Courtesy of NISSAN MOTOR CO., U.S.A.
    CONDITION AND LOAD SIGNALS REFERENCE

    Condition LOAD SIGNAL
    Rear window defogger switch ON ON
    Rear window defogger switch OFF OFF

    OK or NG 

    OK: INSPECTION END 

    NG: GO TO Defogger switch OFF

    OFF

    OK or NG 

    OK: INSPECTION END 

    NG: GO TO  16.

  7. CHECK LOAD SIGNAL CIRCUIT OVERALL FUNCTION-III 

    Without CONSULT-II 

    1. Turn ignition switch ON.
    2. Check voltage between ECM terminal 93 and ground under the following conditions.
      3. Fig 6: Checking Voltage Between ECM Terminal 93 And Ground
      G04191464Courtesy of NISSAN MOTOR CO., U.S.A.
    TERMINALS VOLTAGE REFERENCE

    Condition Voltage
    Rear window defogger switch ON BATTERY VOLTAGE
    Rear window defogger switch OFF Approximately 0V

    OK or NG 

    OK: INSPECTION END 

    NG: GO TO  16.

  8. CHECK HEADLAMP FUNCTION 
    1. Start engine.
    2. Turn the lighting switch ON at 2nd position.
    3. Check that headlamps are illuminated.

    OK or NG 

    OK (Models for USA): GO TO  9.

    OK (Models for Canada): GO TO  11.

    NG: Refer to "HEADLAMP (FOR USA) " or "HEADLAMP (FOR CANADA) - DAYTIME LIGHT SYSTEM - ".

  9. CHECK HEADLAMP INPUT SIGNAL CIRCUIT FOR OPEN AND SHORT 
    1. Stop engine.
    2. Disconnect ECM harness connector.
    3. Disconnect lighting switch harness connector.
    4. Check harness continuity between ECM terminal 84 and lighting switch terminal 12.

      Continuity should exist  .

    5. Also check harness for short to ground and short to power.
      Fig 7: Checking Harness Continuity Between ECM Terminal 84 And Lighting Switch Terminal 12
      G04191465Courtesy of NISSAN MOTOR CO., U.S.A.

    OK or NG 

    OK: GO TO  19.

    NG: GO TO  10.

  10. DETECT MALFUNCTIONING PART 

    Check the following.

    • Fuse block (J/B)
    • Harness connectors M59, F27
    • Harness for open and short between ECM and lighting switch

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

  11. CHECK HEADLAMP INPUT SIGNAL CIRCUIT FOR OPEN AND SHORT 
    1. Stop engine.
    2. Disconnect ECM harness connector.
    3. Disconnect lighting switch harness connector E115. Disconnect daytime light control unit harness connector.
    4. Check harness continuity between ECM terminal 84 and lighting switch terminal 12, daytime light control unit terminal 6 under the following conditions.
      Fig 8: Checking Continuity Between ECM Terminal 84 And Lighting Switch Terminal 12, Daytime Light Control Unit Terminal 6
      G04191466Courtesy of NISSAN MOTOR CO., U.S.A.
      TERMINALS CONTINUITY REFERENCE

      Condition Continuity
      1 Should exist
      2 Should not exist
    5. Also check harness for short to ground and short to power.

    OK or NG 

    OK: GO TO  19.

    NG: GO TO  12.

  12. DETECT MALFUNCTIONING PART 

    Check the following.

    • Harness connectors E109, M20
    • Harness connectors M59, F27
    • Daytime light control unit
    • Fuse block (J/B)
    • Diode-3
    • Harness for open and short between ECM and lighting switch
    • Harness for open and short between ECM and daytime light control unit

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

  13. CHECK HEATER FAN SWITCH FUNCTION 
    1. Start engine.
    2. Turn the heater fan switch ON in any position.
    3. Check that heater fan turns properly.

    OK or NG 

    OK: GO TO  14.

    NG: Refer to "TROUBLE DIAGNOSIS "

  14. CHECK HEATER FAN INPUT SIGNAL CIRCUIT FOR OPEN AND SHORT 
    1. Stop engine.
    2. Disconnect ECM harness connector.
    3. Disconnect fan control switch harness connector.
    4. Check harness continuity between ECM terminal 96 and fan control switch terminal 6.

      Continuity should exist  .

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

    OK or NG 

    OK: GO TO  19.

    NG: GO TO  15.

  15. DETECT MALFUNCTIONING PART 

    Check the following.

    • Harness connectors M59, F27
    • Harness for open and short between ECM and fan control switch

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

  16. CHECK REAR WINDOW DEFOGGER FUNCTION 
    1. Start engine.
    2. Turn ON the rear window defogger switch.
    3. Check the rear windshield. Is the rear windshield heated up?

    Yes or No 

    Yes: GO TO  17.

    No: Refer to "REAR WINDOW DEFOGGER "

  17. CHECK REAR WINDOW DEFOGGER INPUT SIGNAL CIRCUIT FOR OPEN AND SHORT 
    1. Stop engine.
    2. Disconnect ECM harness connector.
    3. Disconnect rear window defogger relay.
    4. Check harness continuity between ECM terminal 93 and rear window defogger relay terminals 5, 7.

      Continuity should exist  .

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

    OK or NG 

    OK: GO TO  19.

    NG: GO TO  18.

  18. DETECT MALFUNCTIONING PART 

    Check the following.

    • Harness connectors B1, M14
    • Harness connectors M58, F26
    • Harness for open and short between ECM and rear window defogger relay.

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

  19. CHECK INTERMITTENT INCIDENT 

    Perform "TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT ".

    : INSPECTION END 

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