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Home >> Lexus >> 2009 >> LS 600hL >> Repair and Diagnosis >> External Pages >> Different car >> Section 11 (Brake Control) >> Electronically Controlled Brake System >> DTC C1249/49 Open in Stop Light Switch Circuit >> Inspection Procedure
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Inspection Procedure

WARNING: This page is about a different car, the 2008 Lexus LS 600hL. However, it is still accessible from the selected car via links, so may be relevant.
NOTE: When replacing the skid control ECU, perform the following operations:
  • Initialization of linear solenoid valve and calibration (see INITIALIZATION  )
  • Yaw rate and acceleration sensor zero point calibration (see CALIBRATION  )
  1. INSPECT FUSE (STOP) 
    1. Remove the STOP fuse from the main body ECU (driver side junction block).
    2. Measure the resistance of the fuse.

      Standard resistance 

      RESISTANCE SPECIFICATION

      Tester Connection Switch Condition Specified Condition
      STOP fuse Always Below 1 Ω

    NG: REPLACE FUSE 

    OK: Go to next step 

  2. READ VALUE USING INTELLIGENT TESTER OR TECHSTREAM (STOP LIGHT SWITCH) 
    1. Connect the Intelligent tester or Techstream to the DLC3
    2. Turn the power switch ON (IG).
    3. Select the DATA LIST mode on the Intelligent tester or Techstream
      1. Intelligent tester

        ABS/VSC: 

        ABS/VSC REFERENCE

        Tester Display Measurement Item/Range Normal Condition
        STOP LAMP SW Stop light switch / ON or OFF ON Brake pedal depressed OFF Brake pedal released
      2. Techstream

        ABS/VSC/TRAC: 

        ABS/VSC/TRAC REFERENCE

        Tester Display Measurement Item/Range Normal Condition
        Stop Lamp Switch Stop light switch / ON or OFF ON Brake pedal depressed OFF Brake pedal released
    4. Check that the stop light observed on the Intelligent tester or Techstream changes when the brake pedal is depressed

      OK: When the brake pedal is depressed, the Intelligent tester or Techstream displays "ON". 

      Result 

      RESULT REFERENCE

      Result Proceed to
      NG (Intelligent tester or Techstream displays "OFF") A
      OK (Intelligent tester or Techstream displays "ON") B

    B: GO TO LIGHTING SYSTEM  (HOW TO PROCEED WITH TROUBLESHOOTING )

    A: Go to next step 

  3. CHECK HARNESS AND CONNECTOR (STOP LIGHT SWITCH - BATTERY) 
    1. Disconnect the A35 switch connector.
      Fig 1: Identifying A35 Connector Terminals
      G04949633Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    2. Measure the voltage according to the value(s) in the table below

      Standard voltage 

      VOLTAGE SPECIFICATION

      Tester Connection Switch Condition Specified Condition
      A35-2 - Body ground Always 11 to 14 V

    NG: REPAIR OR REPLACE HARNESS OR CONNECTOR 

    OK: Go to next step 

  4. INSPECT STOP LIGHT SWITCH 
    1. Disconnect the stop light switch connector.
      Fig 2: Inspecting Stop Light Switch
      G04949634Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    2. Measure the resistance according to the value(s) in the table below.

      Standard resistance 

      RESISTANCE SPECIFICATION

      Tester Connection Switch Condition Specified Condition
      1-2 Switch pin free Below 1 Ω
      1-2 Switch pin pushed in 10 kΩ or higher

    NG: REPLACE STOP LIGHT SWITCH  (See STOP LIGHT SWITCH )

    OK: Go to next step 

  5. CHECK HARNESS AND CONNECTOR (SKID CONTROL ECU - STOP LIGHT SWITCH) 
    1. Disconnect the A21 ECU connector.
    2. Disconnect the A35 switch connector.
      Fig 3: Identifying A21 And A35 Connector Terminals
      G05774006Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    3. Measure the resistance according to the value(s) in the table below

      Standard resistance 

      RESISTANCE SPECIFICATION

      Tester Connection Condition Specified Condition
      A21-25 (STP) - A35-1 Always Below 1 Ω
      A21-25 (STP) - Body ground Always 2 kΩ or lower

    NG: REPAIR OR REPLACE HARNESS OR CONNECTOR 

    OK: Go to next step 

  6. CHECK HARNESS AND CONNECTOR (SKID CONTROL ECU - BODY GROUND) 
    1. Disconnect the A19 and A21 ECU connectors
      Fig 4: Identifying A19 And A21 Connector Terminals
      G04949626Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    2. Measure the resistance according to the value(s) in the table below.

      Standard resistance 

      RESISTANCE SPECIFICATION

      Tester Connection Condition Specified Condition
      A19-1 (GND) - Body ground Always Below 1 Ω
      A21-1 (GND4) - Body ground Always Below 1 Ω

    NG: REPAIR OR REPLACE HARNESS OR CONNECTOR 

    OK: Go to next step 

  7. RECONFIRM DTC 
    1. Clear the DTC (see DTC CHECK / CLEAR  ).
    2. Turn the power switch ON (READY).
    3. Depress the brake pedal several times to test the stop light circuit.
    4. Check if the same DTC is recorded (see DTC CHECK / CLEAR  ).

      HINT:

      Reinstall the sensors, connectors, etc. and restore the vehicle to its prior condition before rechecking for DTCs

      Result 

      RESULT REFERENCE

      Result Proceed to
      DTC (C1249/49) is not output A
      DTC (C1249/49) is output B

      HINT:

      If troubleshooting has been carried out according to the "PROBLEM SYMPTOMS TABLE", refer back to the table and proceed to the next step (see PROBLEM SYMPTOMS TABLE  ).

    B: REPLACE SKID CONTROL ECU  (See REMOVAL  )

    A: USE SIMULATION METHOD TO CHECK  (See HOW TO PROCEED WITH TROUBLESHOOTING )

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