VEHICLE STABILITY CONTROL SYSTEM, Diagnostic DTC:C1249/49

DTC Code DTC Name
C1249/49 Open in Stop Light Switch Circuit

DESCRIPTION

The skid control ECU (housed in the actuator assembly) inputs the stop light switch signal and the condition of brake operation.

The skid control ECU has an open detection circuit, which outputs this DTC when detecting an open in the stop light input line or the ground line of the stop light circuit with the stop light switch off (brake pedal not depressed).

DTC Code DTC Detection Condition Trouble Area
C1249/49

When either of the following is detected:


  1. After the ignition switch is turned to ON, the STP terminal voltage of the ECU is 40 % to 67 % of its supplied voltage for 0.5 seconds.

  2. When STP signal is OFF (release the brake pedal), the pressure sensor value exceeds 725 bar for 1 second.


  • STOP fuse

  • Stop light switch

  • Stop light switch circuit

  • Brake actuator assembly (Skid control ECU)

WIRING DIAGRAM

A0136IPE01

INSPECTION PROCEDURE

PROCEDURE


  1. INSPECT STOP FUSE


    1. A0137G3E01

      Remove the STOP fuse from the instrument panel junction block.

    2. Measure the resistance according to the value(s) in the table below.

      Standard resistance
      Tester Connection Condition Specified Condition
      STOP (10 A) fuse Always Below 1 Ω

    NG
    OK
  2. CHECK STOP LIGHT OPERATION


    1. Install the STOP fuse.

    2. Check that the stop light comes on when the brake pedal is depressed, and goes off when the brake pedal is released.

      OK
      Condition Illumination Condition
      Brake pedal depressed ON
      Brake pedal released OFF

    NG
    OK
  3. INSPECT SKID CONTROL ECU (STP TERMINAL)


    1. A0136MKE33

      Disconnect the skid control ECU connector.

    2. Measure the voltage according to the value(s) in the table below.

      Standard voltage
      Tester Connection Switch Condition Specified Condition
      A41-30 (STP) - Body ground Stop light switch ON (Brake pedal depressed) 8 to 14 V
      A41-30 (STP) - Body ground Stop light switch OFF (Brake pedal released) Below 1.5 V

    NG
    OK
  4. INSPECT SKID CONTROL ECU (IG1 TERMINAL)


    1. A0136MKE32

      Turn the ignition switch to ON.

    2. Measure the voltage according to the value(s) in the table below.

      Standard voltage
      Tester Connection Switch Condition Specified Condition
      A41-28 (IG1) - Body ground Ignition switch ON 11 to 14 V

    NG
    OK
  5. INSPECT SKID CONTROL ECU (GND TERMINAL)


    1. A0136MKE30

      Turn the ignition switch off.

    2. Measure the resistance according to the value(s) in the table below.

      Standard resistance
      Tester Connection Condition Specified Condition
      A41-4 (GND1) - Body ground Always Below 1 Ω
      A41-1 (GND2) - Body ground Always Below 1 Ω

    NG
    OK
  6. RECONFIRM DTC


    1. Reconnect the skid control ECU connector.

    2. Clear the DTC Click here.

    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 Click here.

      Result
      Result Proceed to
      DTC not output A
      DTC output B

      Tech Tips

      If troubleshooting has been carried out according to the Problem Symptoms Table, refer back to the table and proceed to the next step Click here.


    B
    A
  7. INSPECT STOP LIGHT SWITCH (POWER SOURCE TERMINAL)


    1. A0138TOE10

      Disconnect the stop light switch connector.

    2. Measure the voltage according to the value(s) in the table below.

      Standard voltage
      Tester Connection Condition Specified Condition
      A17-2 - Body ground Always 11 to 14 V

    NG
    OK
  8. INSPECT STOP LIGHT SWITCH


    1. A0136QZE01

      Measure the resistance according to the value(s) in the table below.

      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

    NG
    OK
  9. CHECK HARNESS AND CONNECTOR (SKID CONTROL ECU - STOP LIGHT SWITCH)


    1. A01364TE03

      Disconnect the skid control ECU connector.

    2. Measure the resistance according to the value(s) in the table below.

      Standard resistance
      Tester Connection Condition Specified Condition
      A41-30 (STP) - A17-1 Always Below 1 Ω

    NG
    OK
  10. RECONFIRM DTC


    1. Reconnect the skid control ECU connector and the stop light switch connector.

    2. Clear the DTC Click here.

    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 Click here.

      Result
      Result Proceed to
      DTC not output A
      DTC output B

      Tech Tips

      If troubleshooting has been carried out according to the Problem Symptoms Table, refer back to the table and proceed to the next step Click here.


    B
    A