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Home >> Infiniti >> 2005 >> Q45 >> Repair and Diagnosis >> Engine Performance >> System >> Engine Control System - System Testing >> ASCD 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 SW1 INDICATION CONDITIONS

      CONDITION INDICATION
      When brake pedal: Slightly depressed OFF
      When brake pedal: Fully released ON
      Fig 1: Display Data Monitor Mode
      G02369897Courtesy 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.
      ECM TERMINAL 108 AND GROUND VOLTAGE CHECKING CONDITIONS

      CONDITION VOLTAGE
      When brake pedal: Slightly depressed Approximately 0V
      When brake pedal: Fully released Battery voltage
      Fig 2: Checking Voltage Between ECM Terminal 108 And Ground
      G02369898Courtesy 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 SW2 INDICATION CONDITIONS

    CONDITION INDICATION
    When brake pedal: Fully released OFF
    When brake pedal: Slightly depressed ON
    Fig 3: Display Data Monitor Mode
    G02369899Courtesy of NISSAN MOTOR CO., U.S.A.

    Without CONSULT-II 

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

    ECM TERMINAL 101 AND GROUND VOLTAGE CHECKING CONDITIONS

    CONDITION VOLTAGE
    When brake pedal: Fully released Approximately 0V
    When brake pedal: Slightly depressed Battery voltage
    Fig 4: Checking Voltage Between ECM Terminal 101 And Ground
    G02369900Courtesy of NISSAN MOTOR CO., U.S.A.

    OK or NG 

    1. OK: INSPECTION END 
    2. NG: GO TO  8.
  3. CHECK ASCD BRAKE SWITCH POWER SUPPLY CIRCUIT 
    1. Turn ignition switch OFF.
    2. Disconnect ASCD brake switch harness connector.
    3. Turn ignition switch ON.
      Fig 5: Locating ASCD Brake Switch
      G02369901Courtesy of NISSAN MOTOR CO., U.S.A.
    4. Check voltage between ASCD brake switch terminal 1 and ground with CONSULT-II or tester.
      1. Voltage: Battery voltage 

    OK or NG 

    1. OK: GO TO  5.
    2. NG: GO TO 4.
    Fig 6: Checking Voltage Between ASCD Brake Switch Terminal 1 And Ground
    G02369902Courtesy of NISSAN MOTOR CO., U.S.A.
  4. DETECT MALFUNCTIONING PART 

    Check the following.

    • Fuse block (J/B) No. 1 connector M1
    • 10A fuse
    • Harness connectors M61, M401
    • Harness for open or short between ASCD brake switch and fuse
      1. Repair open circuit or short to ground or short to power in harness or connectors.
  5. CHECK ASCD BRAKE SWITCH INPUT SIGNAL CIRCUIT FOR OPEN AND SHORT 
    1. Turn ignition switch OFF.
    2. Disconnect ECM harness connector.
    3. Check harness continuity between ECM terminal 108 and ASCD brake switch terminal 2. Refer to WIRING DIAGRAM .
      1. Continuity should exist. 
    4. Also check harness for short to ground or 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 M401, M61
    • Harness connectors M135, F105
    • Harness for open or short between ECM and ASCD brake switch
      1. Repair open circuit or short to ground or short to power in harness or connectors.
  7. CHECK ASCD BRAKE SWITCH 

    Refer to "COMPONENT INSPECTION "

    OK or NG 

    1. OK: GO TO  13.
    2. NG: Replace ASCD brake switch.
  8. CHECK STOP LAMP SWITCH POWER SUPPLY CIRCUIT 
    1. Turn ignition switch OFF.
    2. Disconnect stop lamp switch harness connector.
      Fig 7: Locating Stop Lamp Switch
      G02369903Courtesy 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  10.
    2. NG: GO TO 9.
    Fig 8: Checking Voltage Between Stop Lamp Switch Terminal 3 And Ground
    G02369904Courtesy of NISSAN MOTOR CO., U.S.A.
  9. DETECT MALFUNCTIONING PART 

    Check the following.

    • Fuse block (J/B) No. 1 connector M1
    • 10A fuse
    • Harness connectors M61, M401
    • 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.
  10. 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  12.
    2. NG: GO TO 11.
  11. DETECT MALFUNCTIONING PART 

    Check the following.

    • Harness connectors M401, M61
    • Harness connectors M135, F105
    • Harness for open or short between ECM and stop lamp switch
      1. Repair open circuit or short to ground or short to power in harness or connectors.
  12. CHECK STOP LAMP SWITCH 

    Refer to "COMPONENT INSPECTION "

    OK or NG 

    1. OK: GO TO 13.
    2. NG: Replace stop lamp switch.
  13. CHECK INTERMITTENT INCIDENT 

    Refer to "TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT ".

    1. INSPECTION END 
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