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Home >> Nissan-Datsun >> 2004 >> Sentra Base, Automatic >> Repair and Diagnosis >> Engine Performance >> System >> 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: Displaying DATA MONITOR Mode
      G00774648Courtesy of NISSAN MOTOR CO., U.S.A.
    3. Check "BRAKE SW1" indication under the following conditions.

      A/T models 

      Fig 2: Brake Switch 1 Indication Conditions Chart (A/T Models)
      G00774646Courtesy of NISSAN MOTOR CO., U.S.A.

      M/T models 

      Fig 3: Brake Switch 1 Indication Conditions Chart (M/T Models)
      G00774647Courtesy 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 

      Fig 4: ECM Terminal 108 And Ground Voltage Checking Conditions (A/T Models)
      G00774649Courtesy of NISSAN MOTOR CO., U.S.A.

      M/T models 

      Fig 5: ECM Terminal 108 And Ground Voltage Checking Conditions (M/T Models)
      G00774650Courtesy of NISSAN MOTOR CO., U.S.A.
      Fig 6: Checking Voltage Between ECM Terminal 108 And Ground
      G00774651Courtesy 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.
      Fig 7: Brake Switch 2 Indication Conditions
      G00774652Courtesy of NISSAN MOTOR CO., U.S.A.
  2. CHECK OVERALL FUNCTION-II 

    With CONSULT-II 

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

    Fig 8: Displaying DATA MONITOR Mode
    G00774653Courtesy of NISSAN MOTOR CO., U.S.A.
    Fig 9: ECM Terminal 101 And Ground Voltage Checking Conditions
    G00774654Courtesy of NISSAN MOTOR CO., U.S.A.

    Without CONSULT-II 

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

    Fig 10: Checking Voltage Between ECM Terminal 101 And Ground
    G00774655Courtesy of NISSAN MOTOR CO., U.S.A.
    Fig 11: Identifying ASCD Clutch Switch
    G00774656Courtesy of NISSAN MOTOR CO., U.S.A.

    OK or NG 

    1. OK: INSPECTION END 
    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.
      Fig 12: Identifying ASCD Brake Switch
      G00774659Courtesy 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 13: ASCD Clutch Switch Terminal 1 And Ground Voltage Checking Condition
      G00774657Courtesy of NISSAN MOTOR CO., U.S.A.
      Fig 14: Checking Voltage Between ASCD Clutch Switch Terminal 1 And Ground
      G00774658Courtesy 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.
      Fig 15: Checking Voltage Between ASCD Brake Switch Terminal 1 And Ground
      G00774660Courtesy of NISSAN MOTOR CO., U.S.A.
    4. Check voltage between ASCD brake switch terminal 1 and ground with CONSULT-II or tester.
      1. Voltage: Battery voltage 

      OK or NG 

      1. OK (M/T models): GO TO  6.
      2. OK (A/T models): GO TO  7.
      3. NG: GO TO 5.
      Fig 16: Identifying Stop Lamp Switch
      G00774661Courtesy of NISSAN MOTOR CO., U.S.A.
  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 .

      1. 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 .

      1. 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 .

      1. 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.
      Fig 17: Checking Voltage Between Stop Lamp Switch Terminal + And Ground ((M/T Models)
      G00774662Courtesy 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.
      1. Voltage: Battery voltage 
      Fig 18: Checking Voltage Between Stop Lamp Switch Terminal 1 And Ground ((A/T Models)
      G00774663Courtesy of NISSAN MOTOR CO., U.S.A.
      Fig 19: Continuity Conditions Chart
      G00774664Courtesy 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 .

      1. 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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