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Home >> Nissan-Datsun >> 2011 >> Sentra SE-R >> Repair and Diagnosis >> Engine Performance >> System >> Engine Control System - DTCS P1148 To P2A03 (Qr25DE) >> DTC P1572 ASCD Brake Switch >> Diagnosis Procedure
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Diagnosis 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 

    BRAKE SWITCH INDICATION CHART

    Condition Indication
    Clutch pedal and/or brake pedal: Slightly depressed OFF
    Clutch pedal and brake pedal: Fully released ON

    CVT models 

    BRAKE SWITCH 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 110 and ground under the following conditions.

    M/T models 

    TERMINAL VOLTAGE REFERENCE CHART

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

    CVT models 

    TERMINAL VOLTAGE REFERENCE CHART

    Condition Voltage
    Brake pedal: Slightly depressed Approximately 0 V
    Brake pedal: Fully released Battery voltage
    Fig 1: Checking Voltage Between ECM Terminal 110 And Ground
    G07144387Courtesy 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.

    BRAKE SWITCH INDICATION CONDITION CHART

    Condition Indication
    Brake pedal: Fully released OFF
    Brake pedal: Slightly depressed ON

    Without CONSULT-III 

    Check voltage between ECM terminal 106 and ground under the following conditions.

    TERMINAL VOLTAGE REFERENCE CHART

    Condition Voltage
    Brake pedal: Fully released Approximately 0 V
    Brake pedal: Slightly depressed Battery voltage
    Fig 2: Checking Voltage Between ECM Terminal 106 And Ground
    G07144388Courtesy of NISSAN MOTOR CO., U.S.A.

    OK or NG 

    OK: GO TO  15.

    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: Location Of ASCD Brake Switch, Stop Lamp Switch And Brake Pedal
      G07144389Courtesy 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 

    Fig 4: Checking Voltage Between ASCD Switch Terminal 1 And Ground
    G07144390Courtesy of NISSAN MOTOR CO., U.S.A.

    OK or NG 

    OK: GO TO  8.

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

    NG (CVT models): GO TO  6.

  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 ASCD Clutch Switch Harness Connector And Clutch Pedal
      G07144391Courtesy 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 

    Fig 6: Checking Voltage Between ASCD Switch Terminal 1 And Ground
    G07144392Courtesy of NISSAN MOTOR CO., U.S.A.

    OK or NG 

    OK: GO TO  7.

    NG: GO TO 5.

  5. DETECT MALFUNCTIONING PART

    Check the following.

    • 10 A 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.

    • 10 A 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 110 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. Refer to "REMOVAL AND INSTALLATION ".

  10. CHECK ASCD CLUTCH SWITCH

    Refer to "COMPONENT INSPECTION "

    OK or NG 

    OK: GO TO  15.

    NG: Replace ASCD clutch switch. Refer to "REMOVAL AND INSTALLATION ".

  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: Location Of ASCD Brake Switch, Stop Lamp Switch And Brake Pedal
      G07144393Courtesy 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
      G07144394Courtesy 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.

    • 10 A 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 106 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. Refer to "REMOVAL AND INSTALLATION ".

  15. CHECK INTERMITTENT INCIDENT

Refer to TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT .

INSPECTION END 

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