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Home › Nissan-Datsun › 2008 › Pathfinder S, RWD › Repair and Diagnosis › Engine Performance › Engine Control Systems › Engine Control System - Component Testing (VQ40DE) › ASCD Brake Switch › Diagnosis Procedure

Diagnosis Procedure

  1. CHECK OVERALL FUNCTION-I

    With CONSULT-III 

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

      CONDITION INDICATION
      When brake pedal: Slightly depressed OFF
      When brake pedal: Fully released ON

    Without CONSULT-III 

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

      CONDITION VOLTAGE
      When brake pedal: Slightly depressed Approximately 0V
      When brake pedal: Fully released Battery voltage
      Fig 1: Checking Voltage Between ECM Terminal 108 And Ground
      G04900670Courtesy of NISSAN MOTOR CO., U.S.A.

    OK or NG 

    OK: GO TO 2.

    NG: GO TO  3.

  2. CHECK OVERALL FUNCTION-II

    With CONSULT-III 

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

    BRAKE SWITCH INDICATION CONDITIONS

    CONDITION INDICATION
    When brake pedal: Fully released OFF
    When brake pedal: Slightly depressed ON

    Without CONSULT-III 

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

    VOLTAGE SPECIFICATION

    CONDITION VOLTAGE
    When brake pedal: Fully released Approximately 0V
    When brake pedal: Slightly depressed Battery voltage
    Fig 2: Checking Voltage Between ECM Connector 101 And Ground
    G04895057Courtesy of NISSAN MOTOR CO., U.S.A.

    OK or NG 

    OK: INSPECTION END 

    NG: GO TO  7.

  3. CHECK ASCD BRAKE SWITCH POWER SUPPLY CIRCUIT
    1. Turn ignition switch OFF.
    2. Disconnect ASCD brake switch harness connector.
      3. Fig 3: Identifying ASCD Brake Switch And Stop Lamp Switch
      G04895051Courtesy of NISSAN MOTOR CO., U.S.A.
    3. Turn ignition switch ON.
    4. Check voltage between ASCD brake switch terminal 1 and ground with CONSULT-III or tester.

      Voltage: Battery voltage 

      Fig 4: Checking Voltage Between ASCD Brake Switch Terminal 1 And Ground
      G04875403Courtesy of NISSAN MOTOR CO., U.S.A.

    OK or NG 

    OK: GO TO  5.

    NG: GO TO 4.

  4. DETECT MALFUNCTIONING PART

    Check the following.

    • Fuse block (J/B) connector E160
    • 10A fuse
    • Harness for open or short between ASCD brake switch and fuse

    Repair open circuit or short to ground 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 .

      Continuity should exist  .

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

    OK or NG 

    OK: GO TO 6.

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

  6. CHECK ASCD BRAKE SWITCH

    Refer to "COMPONENT INSPECTION ".

    OK or NG 

    OK: GO TO  11.

    NG: Replace ASCD brake switch.

  7. CHECK STOP LAMP SWITCH POWER SUPPLY CIRCUIT
    1. Turn ignition switch OFF.
    2. Disconnect stop lamp switch harness connector.
      Fig 5: Identifying ASCD Brake Switch And Stop Lamp Switch
      G04895051Courtesy of NISSAN MOTOR CO., U.S.A.
    3. Check voltage between stop lamp switch terminal 1 and ground with CONSULT-II or tester.

      Voltage: Battery voltage 

      Fig 6: Checking Voltage Between Stop Lamp Switch Terminal 1 And Ground
      G04895061Courtesy of NISSAN MOTOR CO., U.S.A.

    OK or NG 

    OK: GO TO  9.

    NG: GO TO 8.

  8. DETECT MALFUNCTIONING PART

    Check the following.

    • Fuse block (J/B) connector E160
    • 10A fuse
    • Harness for open or short between stop lamp switch and battery

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

  9. 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 2.

      Refer to WIRING DIAGRAM .

      Continuity should exist  .

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

    OK or NG 

    OK: GO TO 10.

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

  10. CHECK STOP LAMP SWITCH

    Refer to "COMPONENT INSPECTION ".

    OK or NG 

    OK: GO TO 11.

    NG: Replace stop lamp switch.

  11. CHECK INTERMITTENT INCIDENT

    Refer to "WORK FLOW ".

    INSPECTION END 

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