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Home >> Nissan-Datsun >> 2004 >> Sentra SE-R >> Repair and Diagnosis >> Engine Performance >> System >> Engine Control System - Qr25DE >> 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. Fig 1: Displaying Data Monitor Mode With Consult-II
      G00778848Courtesy of NISSAN MOTOR CO., U.S.A.
    3. Check "BRAKE SW1" indication under the following conditions.

      A/T models 

      Fig 2: BRAKE SW1 Item Indication Table (A/T Models)
      G00778846Courtesy of NISSAN MOTOR CO., U.S.A.

      M/T models 

      Fig 3: BRAKE SW1 Item Indication Table (M/T Models)
      G00778847Courtesy 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.
      Fig 4: Checking Voltage Between ECM Terminal 108 & Ground
      G00778851Courtesy of NISSAN MOTOR CO., U.S.A.

      A/T models 

      Fig 5: Voltage Condition Table (A/T Models)
      G00778849Courtesy of NISSAN MOTOR CO., U.S.A.

      M/T models 

      Fig 6: Voltage Condition Table (M/T Models)
      G00778850Courtesy of NISSAN MOTOR CO., U.S.A.

    OK or NG 

    1. OK: GO TO 2.
    2. NG (M/T models): GO TO  3.
    3. NG (A/T models): GO TO  4.
  2. CHECK OVERALL FUNCTION-II 

    With CONSULT-II 

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

    Fig 7: Displaying Data Monitor Mode With Consult-II
    G00778853Courtesy of NISSAN MOTOR CO., U.S.A.
    Fig 8: BRAKE SW2 Item Indication Table
    G00778852Courtesy of NISSAN MOTOR CO., U.S.A.

    Without CONSULT-II 

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

    Fig 9: Checking Voltage Between ECM Terminal 101 & Ground
    G00778855Courtesy of NISSAN MOTOR CO., U.S.A.
    Fig 10: Voltage Condition Table
    G00778854Courtesy of NISSAN MOTOR CO., U.S.A.

    OK or NG 

    1. OK: GO TO  18.
    2. NG: GO TO  13.
  3. CHECK ASCD CLUTCH SWITCH POWER SUPPLY CIRCUIT 
    1. Turn ignition switch OFF.
    2. Disconnect ASCD clutch switch harness connector.
    3. Turn ignition switch ON.
      4. Fig 11: Disconnecting ASCD Clutch Switch Harness Connector
      G00778856Courtesy of NISSAN MOTOR CO., U.S.A.
    4. Check voltage between ASCD clutch switch terminal 1 and ground under the following conditions with CONSULT-II or tester.
      Fig 12: Checking Voltage Between ASCD Clutch Switch Terminal 1 & Ground
      G00778858Courtesy of NISSAN MOTOR CO., U.S.A.
      Fig 13: Voltage Condition Table
      G00778857Courtesy of NISSAN MOTOR CO., U.S.A.

    OK or NG 

    1. OK: GO TO  10.
    2. NG: GO TO 4.
  4. CHECK ASCD BRAKE SWITCH POWER SUPPLY CIRCUIT 
    1. Turn ignition switch OFF.
    2. Disconnect ASCD brake switch harness connector.
    3. Turn ignition switch ON.
      4. Fig 14: Disconnecting ASCD Brake Switch Harness Connector
      G00778859Courtesy 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 

      5. Fig 15: Checking Voltage Between ASCD Brake Switch Terminal 1 & Ground
      G00778860Courtesy of NISSAN MOTOR CO., U.S.A.

    OK or NG 

    1. OK (M/T models): GO TO  6.
    2. OK (A/T models): GO TO  7.
    3. NG: GO TO 5.
  5. DETECT MALFUNCTIONING PART 

    Check the following.

    • Fuse block (J/B) connector M1
    • 10A fuse
    • 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.
  6. CHECK ASCD BRAKE SWITCH INPUT SIGNAL CIRCUIT FOR OPEN AND SHORT 
    1. Turn ignition switch OFF.
    2. Check harness continuity between ASCD brake switch terminal 2 and ASCD clutch switch terminal 1. Refer to WIRING DIAGRAM .

      Continuity should exist. 

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

    OK or NG 

    1. OK: GO TO  9.
    2. NG: Repair open circuit or short to ground or short to power in harness or connectors.
  7. 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 or short to power.

    OK or NG 

    1. OK: GO TO  9.
    2. NG: GO TO 8.
  8. DETECT MALFUNCTIONING PART 

    Check the following.

    • Harness connectors M59, F27
    • 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.
  9. CHECK ASCD BRAKE SWITCH 

    Refer to "COMPONENT INSPECTION ".

    OK or NG 

    1. OK: GO TO  18.
    2. NG: Replace ASCD brake switch.
  10. CHECK ASCD CLUTCH 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 clutch switch terminal 2. Refer to WIRING DIAGRAM .

      Continuity should exist. 

    4. Also check harness for short to ground or 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 M59, F27
    • Harness for open or short between ECM and ASCD clutch switch
      1. Repair open circuit or short to ground or short to power in harness or connectors.
  12. CHECK ASCD CLUTCH SWITCH 

    Refer to "COMPONENT INSPECTION ".

    OK or NG 

    1. OK: GO TO  18.
    2. NG: Replace ASCD clutch switch.
  13. CHECK STOP LAMP SWITCH POWER SUPPLY CIRCUIT 
    1. Turn ignition switch OFF.
    2. Disconnect stop lamp switch harness connector.
      3. Fig 16: Disconnecting Stop Lamp Switch Harness Connector
      G00778861Courtesy of NISSAN MOTOR CO., U.S.A.
    3. Check voltage between stop lamp switch terminal + (M/T models) or 1 (A/T models) and ground with CONSULT-II or tester.

      Voltage: Battery voltage 

      Fig 17: Checking Voltage Between Stop Lamp Switch Terminal + & Ground (M/T Models)
      G00778862Courtesy of NISSAN MOTOR CO., U.S.A.
      Fig 18: Checking Voltage Between Stop Lamp Switch Terminal 1 & Ground (A/T Models)
      G00778863Courtesy of NISSAN MOTOR CO., U.S.A.

    OK or NG 

    1. OK: GO TO  15.
    2. NG: GO TO 14.
  14. DETECT MALFUNCTIONING PART 

    Check the following.

    • Fuse block (J/B) connector M2
    • 10A fuse
    • Harness for open or short between stop lamp switch and fuse
      1. 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 - (M/T models) or 2 (A/T models).

      Refer to WIRING DIAGRAM .

      Continuity should exist. 

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

    OK or NG 

    1. OK: GO TO  17.
    2. NG: GO TO 16.
  16. DETECT MALFUNCTIONING PART 

    Check the following.

    • Harness connectors M59, F27
    • 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.
  17. CHECK STOP LAMP SWITCH 

    Refer to "COMPONENT INSPECTION ".

    OK or NG 

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

    Refer to "TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT ".

    1. INSPECTION END 
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