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Home >> Infiniti >> 2005 >> QX56 AWD >> Repair and Diagnosis >> Engine Performance >> Engine Control System >> ICC Brake Switch >> Diagnostic Procedure
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Diagnostic Procedure

  1. CHECK OVERALL FUNCTION-I 

    With CONSULT-II 

    1. Turn ignition switch ON.
    2. Select "BRAKE SW1" in "DATA MONITOR" mode with CONSULT-II.
    3. Check "BRAKE SW1" indication under the following conditions.
      BRAKE LEVEL CONDITION - INDICATION

      CONDITION INDICATION
      Brake pedal: Slightly depressed OFF
      Brake pedal: Fully released ON
      Fig 1: CONSULT-II Display - "BRAKE SW1"
      G02389445Courtesy of NISSAN MOTOR CO., U.S.A.

    Without CONSULT-II 

    1. Turn ignition switch ON.
    2. Check voltage between ECM terminal 108 and ground under the following conditions.
      BRAKE LEVEL CONDITION - VOLTAGE

      CONDITION VOLTAGE
      Brake pedal: Slightly depressed Approximately 0V
      Brake pedal: Fully released Battery voltage
      Fig 2: Checking Voltage Between ECM Terminal 108 And Ground
      G02389446Courtesy of NISSAN MOTOR CO., U.S.A.

    OK or NG 

    1. OK: GO TO 2.
    2. NG: GO TO  3.
  2. CHECK OVERALL FUNCTION-II 

    With CONSULT-II 

    Check "BRAKE SW2" indication in "DATA MONITOR" mode.

    BRAKE LEVEL CONDITION - INDICATION

    CONDITION INDICATION
    Brake pedal: Fully released OFF
    Brake pedal: Slightly depressed ON
    Fig 3: CONSULT-II Display - "BRAKE SW2"
    G02389447Courtesy of NISSAN MOTOR CO., U.S.A.

    Without CONSULT-II 

    Check voltage between ECM terminal 101 and ground under the following conditions.

    BRAKE LEVEL CONDITION - VOLTAGE

    CONDITION VOLTAGE
    Brake pedal: Fully released Approximately 0V
    Brake pedal: Slightly depressed Battery voltage
    Fig 4: Checking Voltage Between ECM Terminal 101 And Ground
    G02389448Courtesy of NISSAN MOTOR CO., U.S.A.

    OK or NG 

    1. OK: INSPECTION END
    2. NG: GO TO  10.
  3. CHECK DTC WITH ICC UNIT 

    Refer to "TROUBLE DIAGNOSIS FOR SELF-DIAGNOSTIC ITEMS ".

    OK or NG 

    1. OK: GO TO 4.
    2. NG: Repair or replace.
  4. CHECK ICC BRAKE HOLD RELAY POWER SUPPLY CIRCUIT 
    1. Turn ignition switch OFF.
    2. Disconnect ICC brake hold relay.
    3. Turn ignition switch ON.
      Fig 5: Locating ICC Brake Hold Relay
      G02389449Courtesy of NISSAN MOTOR CO., U.S.A.
    4. Check voltage between ICC brake hold relay terminal 4 and ground with CONSULT-II or tester.
      1. Voltage: Battery voltage 

    OK or NG 

    1. OK: GO TO  6.
    2. NG: GO TO 5.
    Fig 6: Checking Voltage Between ICC Brake Hold Relay Terminal 4 And Ground
    G02389450Courtesy of NISSAN MOTOR CO., U.S.A.
  5. DETECT MALFUNCTIONING PART 

    Check the following.

    • Harness connectors M31, E152
    • Fuse block (J/B) connector M4
    • 10A fuse
    • Harness for open or short between ICC brake hold relay and battery
      1. Repair open circuit or short to ground or short to power in harness or connectors.
  6. CHECK ICC BRAKE SWITCH POWER SUPPLY CIRCUIT 
    1. Turn ignition switch OFF.
    2. Disconnect ICC brake switch harness connector.
    3. Check harness continuity between ICC brake hold relay terminal 3 and ICC brake switch terminal 1. Refer to WIRING DIAGRAM .
      1. Continuity should exist. 
    4. Also check harness for short to ground and short to power.

    OK or NG 

    1. OK: GO TO 7.
    2. NG: Repair open circuit or short to ground or short to power in harness or connectors.
    Fig 7: Identifying ICC Brake Switch And Stop Lamp Switch
    G02389451Courtesy of NISSAN MOTOR CO., U.S.A.
  7. CHECK ICC BRAKE SWITCH INPUT SIGNAL CIRCUIT FOR OPEN AND SHORT 
    1. Disconnect ECM harness connector.
    2. Check harness continuity between ICC brake switch terminal 2 and ECM terminal 108. Refer Wiring Diagram.
      1. Continuity should exist. 
    3. Also check harness for short to ground and short to power.

    OK or NG 

    1. OK: GO TO 8.
    2. NG: Repair open circuit or short to ground or short to power in harness or connectors.
  8. CHECK ICC BRAKE HOLD RELAY 

    Refer to "COMPONENT INSPECTION ".

    1. OK: GO TO 9.
    2. NG: Replace ICC brake hold relay.
  9. CHECK ICC BRAKE SWITCH 

    Refer to "COMPONENT INSPECTION ".

    OK or NG 

    1. OK: GO TO  14.
    2. NG: Replace ICC brake switch.
  10. CHECK STOP LAMP SWITCH POWER SUPPLY CIRCUIT 
    1. Turn ignition switch OFF.
    2. Disconnect stop lamp switch harness connector.
      Fig 8: Identifying Stop Lamp Switch
      G02389452Courtesy of NISSAN MOTOR CO., U.S.A.
    3. Check voltage between stop lamp switch terminal 3 and ground with CONSULT-II or tester.
      1. Voltage: Battery voltage 

    OK or NG 

    1. OK: GO TO  12.
    2. NG: GO TO 11.
    Fig 9: Checking Voltage Between Stop Lamp Switch Terminal 3 And Ground
    G02389453Courtesy of NISSAN MOTOR CO., U.S.A.
  11. DETECT MALFUNCTIONING PART 

    Check the following.

    • Harness connectors M31, E152
    • Fuse block (J/B) No. 1 connector M60
    • 10A fuse
    • Harness for open or short between stop lamp switch and battery
      1. Repair open circuit or short to ground or short to power in harness or connectors.
  12. CHECK STOP LAMP SWITCH INPUT SIGNAL CIRCUIT FOR OPEN AND SHORT 
    1. Disconnect ECM harness connector.
    2. Check harness continuity between ECM terminal 101 and stop lamp switch terminal 4. Refer to WIRING DIAGRAM .
      1. Continuity should exist. 
    3. Also check harness for short to ground and short to power.

    OK or NG 

    1. OK: GO TO 13.
    2. NG: Repair open circuit or short to ground or short to power in harness or connectors.
  13. CHECK STOP LAMP SWITCH 

    Refer to "COMPONENT INSPECTION ".

    OK or NG 

    1. OK: GO TO 14.
    2. NG: Replace stop lamp switch.
  14. CHECK INTERMITTENT INCIDENT 

    Refer to "TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT ".

    1. : INSPECTION END 
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