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Home >> Nissan-Datsun >> 2008 >> Sentra SL >> Repair and Diagnosis >> Engine Performance >> Engine Control Systems >> Engine Control System - Component Testing (MR20DE) >> ASCD Brake Switch >> Diagnostic Procedure
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Diagnostic Procedure

  1. CHECK OVERALL FUNCTION-I 

    With CONSULT-III 

    1. Turn ignition switch ON.
    2. Select "BRAKE SW1" in "DATA MONITOR" mode with CONSULT-III.
    3. Check "BRAKE SW1" indication under the following conditions.

      M/T models 

      INDICATION CHART

      CONDITION INDICATION
      Clutch pedal and/or brake pedal: Slightly depressed OFF
      Clutch pedal and brake pedal: Fully released ON

      CVT models 

      INDICATION CHART

      CONDITION INDICATION
      Brake pedal: Slightly depressed OFF
      Brake pedal: Fully released ON

    Without CONSULT-III 

    1. Turn ignition switch ON.
    2. Check voltage between ECM terminal 100 and ground under the following conditions.

      M/T models 

      VOLTAGE CHART

      CONDITION VOLTAGE
      Clutch pedal and/or brake pedal: Slightly depressed Approximately 0V
      Clutch pedal and brake pedal: Fully released Battery voltage

      CVT models 

      VOLTAGE CHART

      CONDITION VOLTAGE
      Brake pedal: Slightly depressed Approximately 0V
      Brake pedal: Fully released Battery voltage
      Fig 1: Checking Voltage Between ECM Terminal 100 And Ground
      G04925535Courtesy 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-III 

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

    INDICATION CHART

    CONDITION INDICATION
    Brake pedal: Fully released OFF
    Brake pedal: Slightly depressed ON

    Without CONSULT-III 

    Check voltage between ECM terminal 99 and ground under the following conditions.

    VOLTAGE CHART

    CONDITION VOLTAGE
    Brake pedal: Fully released Approximately 0V
    Brake pedal: Slightly depressed Battery voltage
    Fig 2: Checking Voltage Between ECM Terminal 99 And Ground
    G04900663Courtesy of NISSAN MOTOR CO., U.S.A.

    OK or NG 

    OK: INSPECTION END 

    NG: GO TO  11.

  3. CHECK ASCD BRAKE SWITCH POWER SUPPLY 
    1. Turn ignition switch OFF.
    2. Disconnect ASCD brake switch (1) harness connector.
      • Stop lamp switch (2)
      • Brake pedal (3)
    3. Turn ignition switch ON.
      Fig 3: Identifying ASCD Brake Switch And Stop Lamp Switch
      G04925533Courtesy of NISSAN MOTOR CO., U.S.A.
    4. Check voltage between ASCD brake switch terminal 1 and ground with CONSULT-III or tester.

      Voltage : Battery voltage 

    OK or NG 

    OK: GO TO  8.

    NG (M/T models): GO TO 4.

    NG (CVT models): GO TO  6.

    Fig 4: Checking Voltage Between ASCD Switch Terminal 1 And Ground
    G04875403Courtesy of NISSAN MOTOR CO., U.S.A.
  4. CHECK ASCD CLUTCH SWITCH POWER SUPPLY CIRCUIT 
    1. Turn ignition switch OFF.
    2. Disconnect ASCD clutch switch (1) harness connector.
      • Clutch pedal (2)
    3. Turn ignition switch ON.
      Fig 5: Identifying Clutch Pedal And ASCD Clutch Switch
      G04925539Courtesy of NISSAN MOTOR CO., U.S.A.
    4. Check voltage between ASCD clutch switch terminal 1 and ground with CONSULT-III or tester.

      Voltage: Battery voltage 

    OK or NG 

    OK: GO TO  7.

    NG: GO TO 5.

    Fig 6: Checking Voltage Between ASCD Switch Terminal 1 And Ground
    G04875403Courtesy of NISSAN MOTOR CO., U.S.A.
  5. DETECT MALFUNCTIONING PART 

    Check the following.

    • 10A fuse
    • Harness for open or short between ASCD clutch switch and fuse

    : Repair open circuit or short to ground or short to power in harness or connectors.

  6. DETECT MALFUNCTIONING PART 

    Check the following.

    • 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.

  7. CHECK ASCD CLUTCH SWITCH INPUT SIGNAL CIRCUIT FOR OPEN AND SHORT 
    1. Turn ignition switch OFF.
    2. Check harness continuity between ASCD brake switch terminal 1 and ASCD clutch 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.

  8. 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 100 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 9.

    NG: 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  15.

    NG: Replace ASCD brake switch.

  10. CHECK ASCD CLUTCH SWITCH 

    Refer to "COMPONENT INSPECTION "

    OK or NG 

    OK: GO TO  15.

    NG: Replace ASCD clutch switch.

  11. CHECK STOP LAMP SWITCH POWER SUPPLY CIRCUIT 
    1. Turn ignition switch OFF.
    2. Disconnect stop lamp switch (2) harness connector.
      • ASCD brake switch (1)
      • Brake pedal (3)
        Fig 7: Identifying ASCD Brake Switch And Stop Lamp Switch
        G04925533Courtesy of NISSAN MOTOR CO., U.S.A.
    3. Check voltage between stop lamp switch terminal 1 and ground with CONSULT-III or tester.
      Fig 8: Checking Voltage Between Stop Lamp Switch Terminal 1 And Ground
      G04925542Courtesy of NISSAN MOTOR CO., U.S.A.

      Voltage: Battery voltage 

    OK or NG 

    OK: GO TO  13.

    NG: GO TO 12.

  12. DETECT MALFUNCTIONING PART 

    Check the following.

    • 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.

  13. CHECK STOP LAMP SWITCH INPUT SIGNAL CIRCUIT FOR OPEN AND SHORT 
    1. Disconnect ECM harness connector.
    2. Check harness continuity between ECM terminal 99 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 14.

    NG: Repair open circuit or short to ground or short to power in harness or connectors.

  14. CHECK STOP LAMP SWITCH 

    Refer to "COMPONENT INSPECTION "

    OK or NG 

    OK: GO TO 15.

    NG: Replace stop lamp switch.

  15. CHECK INTERMITTENT INCIDENT 

    Refer to "TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT ".

    : INSPECTION END 

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