LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> Nissan-Datsun >> 2005 >> Pathfinder LE, RWD >> Repair and Diagnosis >> Engine Performance >> Engine Control System >> DTC P1572: ASCD Brake Switch >> Diagnostic Procedure
April 5, 2026: LEMON Manuals is launched! Read the announcement.

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.
      Fig 1: CONSULT-II Display - DATA MONITOR MODE, BRAKE SWI
      G02432364Courtesy of NISSAN MOTOR CO., U.S.A.
    3. Check "BRAKE SW1" indication under the conditions listed in ASCD BRAKE SWITCH 1 DIAGNOSTIC CONDITIONS AND INDICATION - WITH CONSULT-II .
      ASCD BRAKE SWITCH 1 DIAGNOSTIC CONDITIONS AND INDICATION - WITH CONSULT-II

      CONDITION INDICATION
      When brake pedal is slightly depressed OFF
      When brake pedal is fully released ON

    Without CONSULT-II 

    1. Turn ignition switch ON.
    2. Check voltage between ECM terminal 108 and ground under the conditions listed in ASCD BRAKE SWITCH 1 DIAGNOSTIC CONDITIONS AND INDICATION - WITHOUT CONSULT-II .
      ASCD BRAKE SWITCH 1 DIAGNOSTIC CONDITIONS AND INDICATION - WITHOUT CONSULT-II

      CONDITION VOLTAGE
      When brake pedal is slightly depressed Approximately 0V
      When brake pedal is fully released Battery voltage
      Fig 2: Checking Voltage Between ECM Connector Terminal 108 And Ground
      G02432365Courtesy 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-II 

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

    ASCD BRAKE SWITCH 2 DIAGNOSTIC CONDITIONS AND INDICATION - WITH CONSULT-II

    CONDITION INDICATION
    When brake pedal is fully released OFF
    When brake pedal is slightly depressed ON
    Fig 3: CONSULT-II Display - Data Monitor Mode
    G02432366Courtesy of NISSAN MOTOR CO., U.S.A.

    Without CONSULT-II 

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

    ASCD BRAKE SWITCH 2 DIAGNOSTIC CONDITIONS AND INDICATION - WITHOUT CONSULT-II

    CONDITION VOLTAGE
    When brake pedal is fully released Approximately 0V
    When brake pedal is slightly depressed Battery voltage
    Fig 4: Checking Voltage Between ECM Connector Terminal 101 And Ground
    G02432367Courtesy of NISSAN MOTOR CO., U.S.A.

    OK or NG 

    • OK: GO TO 11.
    • 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. Turn ignition switch ON.
      Fig 5: Identifying ASCD Brake Switch And Stop Lamp Switch
      G02432368Courtesy 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 
      Fig 6: Checking Voltage Between ASCD Brake Switch Connector Terminal 1 And Ground
      G02432369Courtesy 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 7: Identifying ASCD Brake Switch And Stop Lamp Switch
      G02432370Courtesy 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 8: Checking Voltage Between Stop Lamp Switch Connector Terminal 1 And Ground
      G02432371Courtesy 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 TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT .

    • : INSPECTION END 
scientia non olet · About LEMON Manuals