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Home >> Nissan-Datsun >> 2005 >> Maxima SL >> Repair and Diagnosis >> Engine Performance >> Engine Control System >> DTC P1572: 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.

      A/T models 

      BRAKE CONDITION - BRAKE SWITCH INDICATION (A/T MODELS)

      CONDITION INDICATION
      When brake pedal: Depressed OFF
      When brake pedal: Fully released ON

      M/T models 

      BRAKE CONDITION - BRAKE SWITCH INDICATION (M/T MODELS)

      CONDITION INDICATION
      When clutch pedal or brake pedal: Depressed OFF
      When clutch pedal and brake pedal: Fully released ON
      Fig 1: CONSULT-II Data Monitor Screen
      G02410621Courtesy 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.

      A/T models 

      BRAKE CONDITION - VOLTAGE (A/T MODELS)

      CONDITION VOLTAGE
      When brake pedal: Depressed Approximately 0V
      When brake pedal: Fully released Battery voltage

      M/T models 

      BRAKE CONDITION - VOLTAGE (M/T MODELS)

      CONDITION VOLTAGE
      When clutch pedal or brake pedal: Depressed Approximately 0V
      When clutch pedal and brake pedal: Fully released Battery voltage
      Fig 2: Checking Voltage Between ECM Terminal 108 & Ground
      G02410622Courtesy of NISSAN MOTOR CO., U.S.A.

    OK or NG

    • OK: GO TO  2.
    • NG (M/T models): GO TO  3.
    • NG (A/T models): GO TO  8.
  2. CHECK OVERALL FUNCTION-II 

    With CONSULT-II 

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

    BRAKE CONDITION - BRAKE SWITCH 2 INDICATION

    CONDITION INDICATION
    When brake pedal: Released OFF
    When brake pedal: Depressed ON
    Fig 3: CONSULT-II Data Monitor Screen
    G02410623Courtesy of NISSAN MOTOR CO., U.S.A.

    Without CONSULT-II 

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

    BRAKE CONDITION - VOLTAGE

    CONDITION VOLTAGE
    When brake pedal: Released Approximately 0V
    When brake pedal: Depressed Battery voltage

    OK or NG

    • OK: GO TO  18.
    • NG: GO TO  13.
      Fig 4: Checking Voltage Between ECM Terminal 101 & Ground
      G02410624Courtesy of NISSAN MOTOR CO., U.S.A.
  3. CHECK ASCD CLUTCH SWITCH CIRCUIT 
    1. Turn ignition switch OFF.
    2. Disconnect ASCD brake switch harness connector.
    3. Turn ignition switch ON.
      Fig 5: Disconnecting ASCD Brake Switch Harness Connector
      G02410625Courtesy of NISSAN MOTOR CO., U.S.A.
    4. Check voltage between ASCD brake switch terminal 1 and ground under the following conditions with CONSULT-II or tester.
      BRAKE CONDITION - VOLTAGE

      CONDITION VOLTAGE
      When clutch pedal: Depressed Approximately 0V
      When clutch pedal: Fully released Battery voltage
      Fig 6: Checking Voltage Between ASCD Brake Switch Terminal 1 & Ground
      G02410626Courtesy of NISSAN MOTOR CO., U.S.A.

    OK or NG

    • OK: GO TO  10.
    • NG: GO TO  4.
  4. CHECK ASCD CLUTCH SWITCH POWER SUPPLY CIRCUIT 
    1. Turn ignition switch OFF.
    2. Disconnect ASCD clutch switch harness connector.
    3. Turn ignition switch ON.
      Fig 7: Disconnecting ASCD Clutch Switch Harness Connector
      G02410627Courtesy of NISSAN MOTOR CO., U.S.A.
    4. Check voltage between ASCD clutch switch terminal 1 and ground with CONSULT-II or tester.

      Voltage: Battery voltage 

    OK or NG

    • OK: GO TO  6.
    • NG: GO TO  5.
      Fig 8: Checking Voltage Between ASCD Clutch Switch Terminal 1 & Ground With CONSULT-II Or Tester
      G02410628Courtesy of NISSAN MOTOR CO., U.S.A.
  5. DETECT MALFUNCTIONING PART 

    Check the following.

    • Fuse block (J/B) connector E30
    • 10A fuse
    • Harness for open or short between ASCD clutch switch and fuse
    • : Repair open circuit or short to ground or short to power in harness or connectors.
  6. CHECK ASCD CLUTCH SWITCH INPUT SIGNAL CIRCUIT FOR OPEN AND SHORT 
    1. Turn ignition switch OFF.
    2. Check harness continuity between ASCD clutch switch terminal 2 and ASCD brake switch terminal 1. Refer to WIRING DIAGRAM - ASC/BS .

      Continuity should exist  .

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

    OK or NG

    • OK: GO TO  7.
    • NG: Repair open circuit or short to ground or short to power in harness or connectors.
  7. CHECK ASCD CLUTCH SWITCH 

    Refer to COMPONENT INSPECTION .

    OK or NG

    • OK: GO TO  18.
    • NG: Replace ASCD clutch switch.
  8. 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 9: Disconnecting ASCD Brake Switch Harness Connector
      G02410629Courtesy of NISSAN MOTOR CO., U.S.A.
    4. Check voltage between ASCD brake switch terminal 1 and ground with CONSULT-II or tester.

      Voltage: Battery voltage 

    OK or NG

    • OK: GO TO  10.
    • NG: GO TO  9.
      Fig 10: Checking Voltage Between ASCD Brake Switch Terminal 1 & Ground With CONSULT-II Or Tester
      G02410630Courtesy of NISSAN MOTOR CO., U.S.A.
  9. DETECT MALFUNCTIONING PART 

    Check the following.

    • Fuse block (J/B) connector E30
    • 10A fuse
    • Harness for open or short between ASCD brake switch and fuse
    • Repair open circuit or short to ground or short to power in harness or connectors.
  10. 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 - ASC/BS .

      Continuity should exist  .

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

    OK or NG

    • OK: GO TO  12.
    • NG: GO TO  11.
  11. DETECT MALFUNCTIONING PART 

    Check the following.

    • Harness connectors E25, M90
    • Harness for open or short between ECM and ASCD brake switch
    • : Repair open circuit or short to ground or short to power in harness or connectors.
  12. CHECK ASCD BRAKE SWITCH 

    Refer to COMPONENT INSPECTION 

    OK or NG

    • OK: GO TO  18.
    • NG: Replace ASCD brake switch.
  13. CHECK STOP LAMP SWITCH POWER SUPPLY CIRCUIT 
    1. Turn ignition switch OFF.
    2. Disconnect stop lamp switch harness connector.
      Fig 11: Disconnecting Stop Lamp Switch Harness Connector
      G02410631Courtesy 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 

    OK or NG

    • OK: GO TO  15.
    • NG: GO TO  14.
      Fig 12: Checking Voltage Between Stop Lamp Switch Terminal & Ground
      G02410632Courtesy of NISSAN MOTOR CO., U.S.A.
  14. DETECT MALFUNCTIONING PART 

    Check the following.

    • Fuse block (J/B) connector E30
    • 10A fuse
    • Harness for open or short between stop lamp switch and fuse
    • : Repair open circuit or short to ground or short to power in harness or connectors.
  15. 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 - ASC/BS .

      Continuity should exist  .

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

    OK or NG

    • OK: GO TO  17.
    • NG: GO TO  16.
  16. DETECT MALFUNCTIONING PART 

    Check the following.

    • Harness connectors E25, M90
    • Harness for open or short between ECM and stop lamp switch
    • : Repair open circuit or short to ground or short to power in harness or connectors.
  17. CHECK STOP LAMP SWITCH 

    Refer to COMPONENT INSPECTION 

    OK or NG

    • OK: GO TO  18.
    • NG: Replace stop lamp switch.
  18. CHECK INTERMITTENT INCIDENT 

    Refer to TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT .

    • INSPECTION END 
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