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Home >> Infiniti >> 2006 >> Q45 >> Repair and Diagnosis >> Engine Performance >> System >> Engine Control System - Q45 - Component & System Tests, Mil And Data Link Connector, Service Data And Specifications (SDS) >> Electrical Load Signal >> Diagnostic Procedure
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Diagnostic Procedure

  1. INSPECTION START 

    Do you have CONSULT-II?

    Yes or No 

    1. Yes: GO TO 2.
    2. No: GO TO  3.
  2. CHECK LOAD SIGNAL CIRCUIT OVERALL FUNCITION-I 

    With CONSULT-II 

    1. Turn ignition switch ON.
    2. Check "LOAD SIGNAL" in "DATA MONITOR" mode with CONSULT-II under the following conditions.
      LOAD SIGNAL CIRCUIT OVERALL FUNCITION-I

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

    OK or NG 

    1. OK: GO TO  4.
    2. NG: GO TO  8.
      Fig 1: Consult-II DATA MONITOR Display Screen
      G04075263Courtesy of NISSAN MOTOR CO., U.S.A.
  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.
      LOAD SIGNAL CIRCUIT OVERALL FUNCTION-I

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

    OK or NG 

    1. OK: GO TO  5.
    2. NG: GO TO  8.
      Fig 2: Checking Voltage Between ECM Terminal 84 And Ground
      G04127797Courtesy of NISSAN MOTOR CO., U.S.A.
  4. CHECK LOAD SIGNAL CIRCUIT OVERALL FUNCTION-II 

    With CONSULT-II 

    Check "LOAD SIGNAL" in "DATA MONITOR" mode with CONSULT-II under the following conditions.

    LOAD SIGNAL CIRCUIT OVERALL FUNCTION-II

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

    OK or NG 

    1. OK: GO TO  6.
    2. NG: GO TO  11.
      Fig 3: Consult-II DATA MONITOR Display Screen
      G04075263Courtesy of NISSAN MOTOR CO., U.S.A.
  5. CHECK LOAD SIGNAL CIRCUIT OVERALL FUNCTION-II 

    Without CONSULT-II 

    Check voltage between ECM terminal 93 and ground under the following conditions.

    LOAD SIGNAL CIRCUIT OVERALL FUNCTION-II

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

    OK or NG 

    1. OK: GO TO  7.
    2. NG: GO TO  11.
      Fig 4: Checking Voltage Between ECM Terminal 93 And Ground
      G04127799Courtesy of NISSAN MOTOR CO., U.S.A.
  6. CHECK HEATER FAN SIGNAL CIRCUIT OVERALL FUNCTION 

    With CONSULT-II 

    Check "HEATER FAN SW" in "DATA MONITOR" mode with CONSULT-II under the following conditions.

    HEATER FAN SIGNAL CIRCUIT OVERALL FUNCTION

    Condition LOAD SIGNAL
    Heater fan control switch: ON ON
    Heater fan control switch: OFF OFF

    OK or NG 

    1. OK: INSPECTION END  .
    2. NG: GO TO  14.
      Fig 5: CONSULT-II Display - Data Monitor
      G04127800Courtesy of NISSAN MOTOR CO., U.S.A.
  7. CHECK HEATER FAN SIGNAL CIRCUIT OVERALL FUNCTION 

    Without CONSULT-II 

    Check voltage between ECM terminal 96 and ground under the following conditions.

    HEATER FAN SIGNAL CIRCUIT OVERALL FUNCTION

    Condition Voltage
    Heater fan control switch: ON 0V
    heater fan control switch: OFF BATTERY VOLTAGE

    OK or NG 

    1. OK: INSPECTION END  .
    2. NG: GO TO  14.
      Fig 6: Checking Voltage Between ECM Terminal 96 And Ground
      G04127801Courtesy of NISSAN MOTOR CO., U.S.A.
  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 

    1. OK: GO TO 9.
    2. NG: Refer to "HEADLAMP (FOR USA) " or "HEADLAMP (FOR CANADA) - DAYTIME LIGHT SYSTEM - ".
  9. CHECK HEADLAMP INPUT SIGNAL CIRCUIT FOR OPEN OR SHORT 
    1. Stop engine.
    2. Disconnect ECM harness connector.
    3. Disconnect headlamp relay-1 harness connector.
    4. Check harness continuity between headlamp relay-1 terminal 5 and ECM terminal 84. Refer to Wiring Diagram .

      Continuity should exist  .

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

    OK or NG 

    1. OK: GO TO  16.
    2. NG: GO TO 10.
  10. DETECT MALFUNCTIONING PART 

    Check the following.

    • Fuse, fusible link and relay block (J/B) connector E3
    • Harness connectors E34, F34
    • Harness for open and short between headlamp relay-1 and ECM
      1. : Repair open circuit or short to ground or short to power in harness or connectors.
  11. 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 

    1. Yes: GO TO 12.
    2. No: Refer to "REAR WINDOW DEFOGGER ".
  12. CHECK REAR WINDOW DEFOGGER INPUT SIGNAL CIRCUIT FOR OPEN OR SHORT 
    1. Stop engine.
    2. Disconnect ECM harness connector.
    3. Disconnect rear window defogger relay.
    4. Check harness continuity between rear window defogger relay terminals 5, 7 and ECM terminal 93. Refer to Wiring Diagram .

      Continuity should exist  .

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

    OK or NG 

    1. OK: GO TO  16.
    2. NG: GO TO 13.
  13. DETECT MALFUNCTIONING PART 

    Check the following.

    • Harness connectors B5, M5
    • Harness connectors M135, F105
    • Harness for open and short between rear window defogger relay and ECM
      1. : Repair open circuit or short to ground or short to power in harness or connectors.
  14. CHECK HEATER FAN CONTROL FUNCTION 
    1. Start engine.
    2. Turn ON the fan control switch.
    3. Check the blower fan motor. Does the blower fan motor activate?

    Yes or No 

    1. Yes: GO TO 15.
    2. No: Refer to "TROUBLE DIAGNOSIS ".
  15. CHECK HEATER FAN SIGNAL CIRCUIT FOR OPEN OR SHORT 
    1. Stop engine.
    2. Disconnect ECM harness connector.
    3. Disconnect A/C AUTO AMP. harness connector.
    4. Check harness continuity between A/C AUTO AMP. terminal 29 and ECM terminal 96. Refer to Wiring Diagram .

      Continuity should exist  .

    5. 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.
  16. CHECK INTERMITTENT INCIDENT 

    Perform "TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT ".

    1. : INSPECTION END 
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