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Home >> Nissan-Datsun >> 2004 >> Sentra Base, Standard >> Repair and Diagnosis >> Engine Performance >> System >> Engine Control System - QG18DE >> 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 

      Fig 1: Displaying DATA MONITOR Mode
      G00773283Courtesy of NISSAN MOTOR CO., U.S.A.
      Fig 2: Brake SW1 Indication Conditions (A/T Models)
      G00773284Courtesy of NISSAN MOTOR CO., U.S.A.

      M/T models 

      Fig 3: Brake SW1 Indication Conditions (M/T Models)
      G00773285Courtesy 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: Voltage Conditions Chart (A/T Models)
      G00773286Courtesy of NISSAN MOTOR CO., U.S.A.

      M/T models 

      Fig 5: Voltage Conditions Chart (M/T Models)
      G00773287Courtesy of NISSAN MOTOR CO., U.S.A.
      Fig 6: Checking Voltage Between ECM Terminal 108 And Ground
      G00773288Courtesy 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: Brake Switch 2 Indication Condition
    G00773289Courtesy of NISSAN MOTOR CO., U.S.A.
    Fig 8: Displaying DATA MONITOR Mode
    G00773290Courtesy of NISSAN MOTOR CO., U.S.A.

    Without CONSULT-II 

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

    Fig 9: ECM Terminal 101 And Ground Voltage Conditions Chart
    G00773291Courtesy of NISSAN MOTOR CO., U.S.A.
    Fig 10: Checking Voltage Between ECM Terminal 101 And Ground
    G00773292Courtesy 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
      Fig 11: Identifying ASCD Clutch Switch
      G00773293Courtesy 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: ASCD Clutch Switch Terminal 1 And Ground Voltage Conditions Chart
      G00773294Courtesy of NISSAN MOTOR CO., U.S.A.
      Fig 13: Checking Voltage Between ASCD Clutch Switch Terminal 1 And Ground
      G00773295Courtesy 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 14: Identifying ASCD Brake Switch
      G00773296Courtesy of NISSAN MOTOR CO., U.S.A.
    4. Check voltage between ASCD brake switch terminal 1 and ground with CONSULT-II or tester.
      Fig 15: Checking Voltage Between ASCD Brake Switch Terminal 1 And Ground
      G00773297Courtesy of NISSAN MOTOR CO., U.S.A.
    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.
  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 16: Identifying Stop Lamp Switch
      G00773298Courtesy 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 17: Checking Voltage Between Stop Lamp Switch Terminal + And Ground (M/T Models)
      G00773299Courtesy of NISSAN MOTOR CO., U.S.A.
      Fig 18: Checking Voltage Between Stop Lamp Switch Terminal 1 And Ground (A/T Models)
      G00773300Courtesy 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 . "TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT".

    1. :INSPECTION END 
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