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Home >> Lexus >> 2008 >> IS F >> Repair and Diagnosis >> Brakes >> Brakes Control Systems >> Brake Control / Dynamic Control Systems >> Vehicle Stability Control System >> DTC C1249/49 Open in Stop Light Switch Circuit >> Inspection Procedure
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Inspection Procedure

NOTE: When replacing the skid control ECU, perform zero point calibration and store system information (See CALIBRATION  ).
  1. CHECK STOP LIGHT OPERATION 
    1. Check that the stop lights come on when the brake pedal is depressed, and go off when the brake pedal is released

      OK 

      BRAKE PEDAL REFERENCE

      Condition Illumination Condition
      Brake pedal depressed ON
      Brake pedal released OFF

    NG: Go to step  6

    OK: Go to next step 

  2. READ VALUE USING TECHSTREAM (STOP LIGHT SWITCH AND BRAKE PEDAL LOAD SENSING SWITCH) 
    1. Connect the Techstream to the DLC3
    2. Turn the engine switch on (IG).
    3. Select the Data List mode on the Techstream (See DATA LIST / ACTIVE TEST  )

      ABS/VSC/TRAC 

      NORMAL CONDITION

      Tester Display Measurement Item / Range Normal Condition Diagnostic Note
      Stop Light SW Stop light switch / ON or OFF ON Brake pedal depressed
      OFF Brake pedal released      		 -
      Brake Pedal Load Sensing SW Brake pedal load sensing switch / ON or OFF ON Brake pedal depressed beyond the specified point
      OFF Brake pedal not depressed beyond the specified point      		 -
    4. Check that the stop light display observed on the Techstream changes when the brake pedal is depressed

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

    5. Depress the brake pedal slowly, and check when the stop light switch and brake pedal load sensing switch turn ON.

      OK: First the stop light switch should turn ON, and then the brake pedal load sensing switch should turn ON. 

      Result 

      RESULT REFERENCE

      Result Proceed to
      OK A
      NG (The stop light switch does not turn on) B
      NG (The brake pedal load sensing switch turns on first) C

    B: Go to step  15

    C: Go to step  16

    A: Go to next step 

  3. INSPECT SKID CONTROL ECU (IG1 TERMINAL) 
    1. Turn the engine switch off.
    2. Make sure that there is no looseness at the locking part and the connecting part of the connector
    3. Disconnect the skid control ECU connector.
    4. Turn the engine switch on (IG)
    5. Measure the voltage according to the value(s) in the table below.

      Standard Voltage 

      STANDARD VOLTAGE

      Tester Connection Switch Condition Specified Condition
      J77-1 (IG1) - Body ground Engine switch on (IG) 11 to 14 V
      6. Fig 1: Identifying Skid Control ECU (IG1 Terminal)
      G05752613Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    NG: REPAIR OR REPLACE HARNESS OR CONNECTOR (IG1 CIRCUIT) 

    OK: Go to next step 

  4. INSPECT SKID CONTROL ECU (GND TERMINAL) 
    1. Turn the engine switch off
    2. Make sure that there is no looseness at the locking part and the connecting part of the connectors.
    3. Disconnect the skid control ECU connectors
    4. Measure the resistance according to the value(s) in the table below

      Standard Resistance 

      STANDARD RESISTANCE

      Tester Connection Condition Specified Condition
      J78-26 (GND1) - Body ground Always Below 1 Ω
      J78-14 (GND2) - Body ground Always Below 1 Ω
      A35-22 (GND3) - Body ground Always Below 1 Ω
      5. Fig 2: Identifying Skid Control ECU (GND Terminal)
      G05752614Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    NG: REPAIR OR REPLACE HARNESS OR CONNECTOR (GND CIRCUIT) 

    OK: Go to next step 

  5. RECONFIRM DTC 
    1. Reconnect the skid control ECU connectors.
    2. Clear the DTCs (See DTC CHECK / CLEAR  ).
    3. Start the engine
    4. Depress the brake pedal several times to test the stop light circuit.
    5. Check if the same DTC is recorded (See DTC CHECK / CLEAR  )

      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 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: CHECK FOR INTERMITTENT PROBLEMS (SYMPTOM SIMULATION)  (See DIAGNOSIS SYSTEM  )

  6. INSPECT STOP SW FUSE 
    1. Remove the STOP SW fuse from the main body ECU RH (cowl side junction block RH).
    2. Measure the resistance according to the value(s) in the table below.

      Standard Resistance 

      STANDARD RESISTANCE

      Tester Connection Condition Specified Condition
      STOP SW (7.5 A) fuse Always Below 1 Ω
      3. Fig 3: Identifying Stop SW Fuse
      G05752624Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    NG: REPLACE STOP SW FUSE 

    OK: Go to next step 

  7. INSPECT STOP LIGHT SWITCH (POWER SOURCE TERMINAL) 
    1. Install the STOP SW fuse.
    2. Make sure that there is no looseness at the locking part and the connecting part of the connector.
    3. Disconnect the stop light switch connector.
    4. Measure the voltage according to the value(s) in the table below

      Standard Voltage 

      STANDARD VOLTAGE

      Tester Connection Condition Specified Condition
      A22-2 - Body ground Always 11 to 14 V
      5. Fig 4: Identifying Stop Light Switch (Power Source Terminal)
      G05752625Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    NG: REPAIR OR REPLACE HARNESS OR CONNECTOR (POWER SOURCE CIRCUIT) 

    OK: Go to next step 

  8. INSPECT STOP LIGHT SWITCH 
    1. Measure the resistance according to the value(s) in the table below.

      Standard Resistance 

      STANDARD RESISTANCE

      Tester Connection Switch Condition Specified Condition
      1 - 2 Switch pin free Below 1 Ω
      1 - 2 Switch pin pushed in 10 kΩ or higher
      2. Fig 5: Identifying Stop Light Switch
      G05750570Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    NG: REPLACE STOP LIGHT SWITCH  (See REMOVAL )

    OK: Go to next step 

  9. INSPECT STOP LIGHT CONTROL RELAY (BRK-LP) 
    1. Remove the stop light control (BRK-LP) relay.
    2. Measure the resistance according to the value(s) in the table below

      Standard Resistance 

      STANDARD RESISTANCE

      Tester Connection Condition Specified Condition
      3 - 4 Voltage is not applied between terminals 1 and 2 Below 1 Ω
      3. Fig 6: Identifying Stop Light Control Relay (BRK-LP)
      G05752627Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    NG: REPLACE STOP LIGHT CONTROL RELAY (BRK-LP) 

    OK: Go to next step 

  10. INSPECT STOP LIGHT CONTROL RELAY 
    1. Check the stop light control relay (See INSPECTION )

      OK: The stop light control relay is normal. 

    NG: REPLACE STOP LIGHT CONTROL RELAY  (See REMOVAL )

    OK: Go to next step 

  11. CHECK HARNESS AND CONNECTOR (STOP LIGHT SWITCH - STOP LIGHT CONTROL RELAY) 
    1. Make sure that there is no looseness at the locking part and the connecting part of the connector
    2. Disconnect the stop light control relay connector
    3. Measure the resistance according to the value(s) in the table below

      Standard Resistance 

      STANDARD RESISTANCE

      Tester Connection Condition Specified Condition
      A22-1 - J96-2 (STP) Always Below 1 Ω
      A22-1 - Body ground Always 10 kΩ or higher
      4. Fig 7: Identifying Harness And Connector (Stop Light Switch - Stop Light Control Relay)
      G05752628Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    NG: REPAIR OR REPLACE HARNESS OR CONNECTOR 

    OK: Go to next step 

  12. CHECK HARNESS AND CONNECTOR (STOP LIGHT CONTROL RELAY - ENGINE ROOM NO. 3 RELAY BLOCK) 
    1. Measure the resistance according to the value(s) in the table below

      Standard Resistance 

      STANDARD RESISTANCE

      Tester Connection Condition Specified Condition
      J96-8 (OUT) -Stop light control (BRK-LP) relay terminal 4 Always Below 1 Ω
      J96-8 (OUT) - Body ground Always 10 kΩ. or higher
      2. Fig 8: Identifying Harness And Connector (Stop Light Control Relay - Engine Room No. 3 Relay Block)
      G05752629Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    NG: REPAIR OR REPLACE HARNESS OR CONNECTOR 

    OK: Go to next step 

  13. CHECK HARNESS AND CONNECTOR (SKID CONTROL ECU - ENGINE ROOM NO. 3 RELAY BLOCK) 
    1. Make sure that there is no looseness at the locking part and the connecting part of the connector.
    2. Disconnect the skid control ECU connector
    3. Measure the resistance according to the value(s) in the table below

      Standard Resistance 

      STANDARD RESISTANCE

      Tester Connection Condition Specified Condition
      J77-10 (STP1) - Stop light control (BRK-LP) relay terminal 3 Always Below 1 Ω
      4. Fig 9: Identifying Harness And Connector (Skid Control ECU - Engine Room No. 3 Relay Block)
      G05752630Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    NG: REPAIR OR REPLACE HARNESS OR CONNECTOR 

    OK: Go to next step 

  14. RECONFIRM DTC 
    1. Clear the DTCs (See DTC CHECK / CLEAR  )
    2. Start the engine.
    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 relay, 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 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: INSPECT LIGHTING SYSTEM (STOP LIGHT CIRCUIT)  (See PROBLEM SYMPTOMS TABLE )

  15. CHECK HARNESS AND CONNECTOR (SKID CONTROL ECU - ENGINE ROOM NO. 3 RELAY BLOCK) 
    1. Turn the engine switch off
    2. Remove the stop light control (BRK-LP) relay
    3. Make sure that there is no looseness at the locking part and the connecting part of the connector.
    4. Disconnect the skid control ECU connector
    5. Measure the resistance according to the value(s) in the table below

      Standard Resistance 

      STANDARD RESISTANCE

      Tester Connection Condition Specified Condition
      J77-10 (STP1) - Stop light control (BRK-LP) relay terminal 3 Always Below 1 Ω

      HINT

      If troubleshooting has been carried out according to Problem Symptoms Table, refer back to the table and proceed to the next step (See PROBLEM SYMPTOMS TABLE  )

      6. Fig 10: Identifying Harness And Connector (Skid Control ECU - Engine Room No. 3 Relay Block)
      G05752630Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    NG: REPAIR OR REPLACE HARNESS OR CONNECTOR 

    OK: REPLACE SKID CONTROL ECU  (See REMOVAL  )

  16. CHECK BRAKE PEDAL AND STOP LIGHT SWITCH INSTALLATION 
    1. Turn the engine switch off
    2. Check the brake pedal height and stop light switch installation (See ADJUSTMENT for brake pedal,INSPECTION for stop light.)

      OK: The brake pedal height and stop light switch installation are normal. 

      HINT

      If troubleshooting has been carried out according to Problem Symptoms Table, refer back to the table and proceed to the next step (See PROBLEM SYMPTOMS TABLE  ).

    NG: ADJUST BRAKE PEDAL OR STOP LIGHT SWITCH  (See ADJUSTMENT )

    OK: REPLACE BRAKE PEDAL SUPPORT ASSEMBLY (BRAKE PEDAL LOAD SENSING SWITCH)  (See REMOVAL )

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