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Home >> Nissan-Datsun >> 2004 >> Sentra SE-R >> Repair and Diagnosis >> External Pages >> Different car >> Section 1481 (Engine Control System) >> ASCD Brake Switch >> Diagnostic Procedure
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Diagnostic Procedure

WARNING: This page is about a different car, the 2005 Nissan Quest. However, it is still accessible from the selected car via links, so may be relevant.
  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 Data Monitor Display
      G02474721Courtesy of NISSAN MOTOR CO., U.S.A.
    3. Check "BRAKE SW1" indication under the following conditions.
      INDICATOR CONDITION TABLE

      CONDITION INDICATION
      When brake pedal is slightly depressed OFF
      When brake pedal is 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 Terminal 108 & Ground
      G02474722Courtesy of NISSAN MOTOR CO., U.S.A.
      VOLTAGE CONDITION TABLE

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

    OK or NG

    • OK: GO TO 2.
    • NG: GO TO  3.
  2. CHECK OVERALL FUNCTION-II 

    With CONSULT-II 

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

    Fig 3: CONSULT-II Data Monitor Display
    G02474723Courtesy of NISSAN MOTOR CO., U.S.A.
    INDICATOR CONDITION TABLE

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

    Without CONSULT-II 

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

    Fig 4: Checking Voltage Between ECM Terminal 101 & Ground
    G02474724Courtesy of NISSAN MOTOR CO., U.S.A.
    VOLTAGE CONDITION TABLE

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

    OK or NG

    • OK: INSPECTION END 
    • NG: GO TO  7.
  3. CHECK ASCD BRAKE SWITCH POWER SUPPLY CIRCUIT 
    1. Turn ignition switch OFF.
    2. Disconnect ASCD brake switch harness connector.
      Fig 5: Disconnecting ASCD Brake Switch Harness Connector
      G02474725Courtesy 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.
      Fig 6: Checking Voltage Between ASCD Brake Switch Terminal 1 & Ground
      G02474726Courtesy of NISSAN MOTOR CO., U.S.A.
      • Voltage: Battery voltage 

    OK or NG

    • OK: GO TO  5.
    • NG: GO TO 4.
  4. DETECT MALFUNCTIONING PART 

    Check the following.

    • Fuse block (J/B) connector E30
    • 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.
  5. 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 and short to power.

    OK or NG

    • OK: GO TO 6.
    • NG: Repair open circuit or short to ground or short to power in harness or connectors.
  6. CHECK ASCD BRAKE SWITCH 

    Refer to "COMPONENT INSPECTION ".

    OK or NG

    • OK: GO TO  11.
    • NG: Replace ASCD brake switch.
  7. CHECK STOP LAMP SWITCH POWER SUPPLY CIRCUIT 
    1. Turn ignition switch OFF.
    2. Disconnect stop lamp switch harness connector.
      Fig 7: Disconnecting Stop Lamp Switch Harness Connector
      G02474727Courtesy of NISSAN MOTOR CO., U.S.A.
    3. Check voltage between stop lamp switch terminal 1 and ground with CONSULT-II or tester.
      Fig 8: Checking Voltage Between Stop Lamp Switch Terminal 1 & Ground
      G02474728Courtesy of NISSAN MOTOR CO., U.S.A.
      • Voltage: Battery voltage 

    OK or NG

    • OK: GO TO  9.
    • NG: GO TO 8.
  8. DETECT MALFUNCTIONING PART 

    Check the following.

    • Fuse block (J/B) connector E30
    • 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.
  9. 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 10.
    • NG: Repair open circuit or short to ground or short to power in harness or connectors.
  10. CHECK STOP LAMP SWITCH 

    Refer to "COMPONENT INSPECTION ".

    OK or NG

    • OK: GO TO 11.
    • NG: Replace stop lamp switch.
  11. CHECK INTERMITTENT INCIDENT 

    Refer to "TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT ".

    • : INSPECTION END 
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