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Home >> Nissan-Datsun >> 2002 >> Sentra SE-R, Automatic >> Repair and Diagnosis >> External Pages >> Different car >> Section 1437 (Engine Control System) >> DTC P1805: Brake Switch >> Diagnostic Procedure
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Diagnostic Procedure

WARNING: This page is about a different car, the 2005 Nissan 350Z. However, it is still accessible from the selected car via links, so may be relevant.
  1. CHECK STOP LAMP SWITCH CIRCUIT 
    1. Turn ignition switch OFF.
    2. Check the stop lamp when depressing and releasing the brake pedal.
    BRAKE PEDAL STOP LAMP SPECIFICATION

    Brake pedal Stop lamp
    Fully released Not illuminated
    Slightly depressed Illuminated

    OK or NG

    • OK: GO TO  4.
    • NG: GO TO 2.
  2. CHECK STOP LAMP SWITCH POWER SUPPLY CIRCUIT 
    1. Disconnect stop lamp switch harness connector.
      Fig 1: Disconnecting Stop Lamp Switch Harness Connector
      G02402105Courtesy of NISSAN MOTOR CO., U.S.A.
    2. Check voltage between stop lamp switch terminal 1 and ground with CONSULT-II or tester.
      Fig 2: Stop Lamp Switch Terminal 1 & Ground Voltage Test
      G02402106Courtesy of NISSAN MOTOR CO., U.S.A.
      • Voltage: Battery voltage 

    OK or NG

    • OK: GO TO  4.
    • NG: GO TO 3.
  3. DETECT MALFUNCTIONING PART 

    Check the following.

    • 10A fuse
    • Fuse block (J/B) connector E101
    • Harness for open and short between stop lamp switch and fuse
      • : 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. Disconnect ECM harness connector.
    2. Disconnect stop lamp switch harness connector.
    3. Check harness continuity between ECM terminal 101 and stop lamp 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: GO TO 5.
    Fig 3: Disconnecting Stop Lamp Switch Harness Connector
    G02402107Courtesy of NISSAN MOTOR CO., U.S.A.
  5. DETECT MALFUNCTIONING PART 

    Check the following.

    • Harness connectors E108, M15
    • Harness connectors M72, F102
    • Harness for open or short between ECM and stop lamp switch
      • : 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

    • OK: GO TO 7.
    • NG: Replace stop lamp switch.
  7. CHECK INTERMITTENT INCIDENT 

    Refer to "TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT ".

    • : INSPECTION END 
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