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Home >> Nissan-Datsun >> 2005 >> Sentra Base, Automatic >> Repair and Diagnosis >> Engine Performance >> Engine Control System (QG18DE) >> 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.
      Fig 1: CONSULT-II Display - DATA MONITOR, BRAKE SW1
      G02450564Courtesy of NISSAN MOTOR CO., U.S.A.
    3. Check "BRAKE SW1" indication under the following conditions.

    A/T models 

    BRAKE SWITCH 1 INDICATION CONDITIONS - A/T MODELS

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

    M/T models 

    BRAKE SWITCH 1 INDICATION CONDITIONS - M/T MODELS

    CONDITION INDICATION
    When clutch pedal or brake pedal is depressed OFF
    When clutch pedal and brake pedal are fully released ON

    Without CONSULT-II 

    1. Turn ignition switch ON.
    2. Check voltage between ECM terminal 108 and ground under the following conditions.
      Fig 2: Checking Voltage Between ECM Connector Terminal 108 And Ground
      G02450565Courtesy of NISSAN MOTOR CO., U.S.A.

      A/T models 

      ECM TERMINAL 108 VOLTAGE CONDITIONS - A/T MODELS

      CONDITION VOLTAGE
      When brake pedal is depressed Approximately 0V
      When brake pedal is fully released Battery voltage

      M/T models 

      ECM TERMINAL 108 VOLTAGE CONDITIONS - M/T MODELS

      CONDITION VOLTAGE
      When clutch pedal or brake pedal is depressed Approximately 0V
      When clutch pedal and brake pedal are fully released Battery voltage

    OK or NG 

    • OK : GO TO 2.
    • NG (M/T models) : GO TO  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 3: CONSULT-II Display - DATA MONITOR, BRAKE SW2
    G02450566Courtesy of NISSAN MOTOR CO., U.S.A.
    BRAKE SWITCH 2 INDICATION CONDITIONS (CONSULT-II)

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

    Without CONSULT-II 

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

    Fig 4: Checking Voltage Between ECM Connector Terminal 101 And Ground
    G02450567Courtesy of NISSAN MOTOR CO., U.S.A.
    ECM CONNECTOR TERMINAL 101 VOLTAGE CONDITIONS

    CONDITION VOLTAGE
    When brake pedal is released Approximately 0V
    When brake pedal is depressed Battery voltage

    OK or NG 

    • OK : INSPECTION END 
    • NG : GO TO  13.
  3. CHECK ASCD CLUTCH SWITCH POWER SUPPLY CIRCUIT 
    1. Turn ignition switch OFF.
    2. Disconnect ASCD clutch switch harness connector.
      Fig 5: Identifying ASCD Clutch Switch
      G02450568Courtesy of NISSAN MOTOR CO., U.S.A.
    3. Turn ignition switch ON.
    4. Check voltage between ASCD clutch switch terminal 1 and ground under the following conditions with CONSULT-II or tester.
      5. Fig 6: Checking Voltage Between ASCD Clutch Switch Connector Terminal 1 And Ground
      G02450569Courtesy of NISSAN MOTOR CO., U.S.A.
    ASCD CLUTCH SWITCH TERMINAL 1 TERMINAL VOLTAGE

    CONDITION VOLTAGE
    When brake pedal is released Battery voltage
    When brake pedal is depressed Approx. 0V

    OK or NG 

    • OK : GO TO  10.
    • NG : GO TO 4.
  4. CHECK ASCD BRAKE SWITCH POWER SUPPLY CIRCUIT 
    1. Turn ignition switch OFF.
    2. Disconnect ASCD brake switch harness connector.
      Fig 7: Identifying ASCD Brake Switch
      G02450570Courtesy 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-II or tester.
      • Voltage: Battery voltage 
      Fig 8: Checking Voltage Between ASCD Brake Switch Connector Terminal 1 And Ground
      G02450571Courtesy of NISSAN MOTOR CO., U.S.A.

    OK or NG 

    • OK (M/T models) : GO TO  6.
    • OK (A/T models) : GO TO  7.
    • 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
      • : 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 

    • OK : GO TO  9.
    • 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 

    • OK : GO TO  9.
    • 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
      • : 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 

    • OK : GO TO  18.
    • 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 

    • OK : GO TO  12.
    • 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
      • : 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 

    • OK : GO TO  18.
    • 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.
      Fig 9: Identifying Stop Lamp Switch
      G02450572Courtesy of NISSAN MOTOR CO., U.S.A.
    3. Check voltage between stop lamp switch terminal 1 and ground with CONSULT -II or tester.
      Fig 10: Checking Voltage Between Stop Lamp Switch Connector Terminal 1 And Ground
      G02450573Courtesy of NISSAN MOTOR CO., U.S.A.
      • Voltage: Battery voltage 

    OK or NG 

    • OK : GO TO  15.
    • 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
      • : 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 .
      • 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 M59, F27
    • 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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