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Home >> Nissan-Datsun >> 2004 >> Pathfinder LE, RWD >> Repair and Diagnosis >> Engine Performance >> System >> Engine Control System >> DTC P1805: Brake Switch >> Diagnostic Procedure
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Diagnostic Procedure

  1. CHECK STOP LAMP SWITCH CIRCUIT 
    1. Turn ignition switch "OFF".
    2. Check the stop lamp when depressing and releasing the brake pedal.
      Fig 1: Stop Lamp Switch Circuit Inspection Chart
      G00781237Courtesy of NISSAN MOTOR CO., U.S.A.

    OK or NG 

    1. OK GO TO  4 .
    2. NG GO TO 2.
  2. CHECK STOP LAMP SWITCH POWER SUPPLY CIRCUIT 
    1. Disconnect stop lamp switch harness connector.
      Fig 2: Identifying ASCD Brake Switch And Stop Lamp Switch
      G00781238Courtesy of NISSAN MOTOR CO., U.S.A.
    2. Check voltage between stop lamp switch terminal 1 and ground with CONSULT-II or tester.
      Fig 3: Checking Voltage Between Stop Lamp Switch Terminal 1 And Ground With CONSULT-II Or Tester
      G00781239Courtesy of NISSAN MOTOR CO., U.S.A.
      Fig 4: Checking Voltage Between Stop Lamp Switch Terminal 1 And Ground With CONSULT-II Or Tester (M/T Model)
      G00781240Courtesy of NISSAN MOTOR CO., U.S.A.

      Voltage: Battery voltage 

    OK or NG 

    1. OK GO TO  4 .
    2. NG GO TO 3.
  3. DETECT MALFUNCTIONING PART 

    Check the following.

    • 10A fuse
    • Fuse block (J/B) connector M10
    • Harness for open and short between stop lamp switch and battery
    1. Repair open circuit or short to ground or short to power in harness or connectors.
  4. CHECK STOP LAMP SWITCH INPUT SIGNAL CIRCUIT FOR OPEN AND SHORT 
    1. Turn ignition switch "OFF".
    2. Disconnect ECM harness connector.
    3. Disconnect stop lamp switch harness connector.
      Fig 5: Identifying ASCD Brake Switch And Stop Lamp Switch
      G00781241Courtesy of NISSAN MOTOR CO., U.S.A.
    4. Check harness continuity between ECM terminal 101 and stop lamp switch terminal 2.

      Refer to WIRING DIAGRAM  .

      Continuity should exist. 

    5. Also check harness for short to ground and short to power.

    OK or NG 

    1. OK GO TO  6 .
    2. NG GO TO 5.
  5. DETECT MALFUNCTIONING PART 

    Check the following.

    • Harness connector M94, F27
    • Harness for open and short between ECM and stop lamp switch
    1. Repair open circuit or short to ground or short to power in harness or connectors.
  6. CHECK STOP LAMP SWITCH 

    Refer to "COMPONENT INSPECTION  " .

    OK or NG 

    1. OK GO TO 7.
    2. NG Replace stop lamp switch.
  7. CHECK INTERMITTENT INCIDENT 

    Refer to "TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT  " .

    1. INSPECTION END