ELECTRONICALLY CONTROLLED BRAKE SYSTEM TRC OFF Indicator Light Remains ON

DESCRIPTION

The skid control ECU (brake booster with master cylinder assembly) is connected to the combination meter assembly via CAN communication.

Pressing the VSC OFF switch (integration control and panel assembly) turns off TRC control and pressing and holding this switch turns off TRC and VSC controls. If TRC control is turned off, the TRC OFF message is displayed on the multi-information display in the combination meter assembly.

WIRING DIAGRAM

A00094GE96

CAUTION / NOTICE / HINT

Note

When replacing the skid control ECU (brake booster with master cylinder assembly), perform initialization and calibration of the linear solenoid valve Click here.

PROCEDURE


  1. CHECK CAN COMMUNICATION SYSTEM


    1. Check if CAN communication system DTCs are output Click here.

      Result
      Result Proceed to
      DTCs are not output. A
      DTCs are output. B

    B

    INSPECT CAN COMMUNICATION SYSTEM Click here

    A

  2. CHECK IF BRAKE BOOSTER WITH MASTER CYLINDER ASSEMBLY CONNECTOR IS SECURELY CONNECTED


    1. Check if the skid control ECU (brake booster with master cylinder assembly) connector is securely connected.

      OK
      The connector is securely connected.

    NG

    CONNECT CONNECTOR TO BRAKE BOOSTER WITH MASTER CYLINDER ASSEMBLY CORRECTLY

    OK

  3. CHECK AUXILIARY BATTERY


    1. Check the auxiliary battery voltage.

      Standard Voltage
      Tester Connection Condition Specified Condition
      Auxiliary battery Power switch on (IG) 11 to 14 V
      Auxiliary battery Power switch on (READY) 11 to 15.5 V

    NG

    CHARGE OR REPLACE AUXILIARY BATTERY

    OK

  4. READ VALUE USING GTS (VSC OFF SWITCH)


    1. Connect the GTS to the DLC3.

    2. Turn the power switch on (IG).

    3. Select the Data List on the GTS Click here.

      ABS/VSC/TRC
      Tester Display Measurement Item/Range Normal Condition Diagnostic Note
      TRC/VSC Off Mode TRC/VSC off mode / Normal, TRC OFF, Unknown or VSC OFF

      Normal: Normal mode

      TRC OFF: TRC off mode

      Unknown: Unspecified

      VSC OFF: VSC off mode

      		 -

    4. Using the GTS, check that the switch condition on the GTS changes according to VSC OFF switch (integration control and panel assembly) operation.

      OK
      The GTS display changes according to VSC OFF switch (integration control and panel assembly) operation.

    NG

    INSPECT INTEGRATION CONTROL AND PANEL ASSEMBLY Click here

    OK

  5. INSPECT COMBINATION METER ASSEMBLY


    1. Turn the power switch off.

    2. Perform the Active Test of the combination meter assembly (meter CPU) using the GTS Click here.

    3. Check the combination meter assembly.

      OK
      The multi-information display turns on or off in accordance with GTS operation.
      Result
      Result Proceed to
      OK (for LHD) A
      OK (for RHD) B
      NG C

      Tech Tips

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


    A

    REPLACE BRAKE BOOSTER WITH MASTER CYLINDER ASSEMBLY Click here

    B

    REPLACE BRAKE BOOSTER WITH MASTER CYLINDER ASSEMBLY Click here

    C

    REPLACE COMBINATION METER ASSEMBLY Click here

  6. INSPECT INTEGRATION CONTROL AND PANEL ASSEMBLY


    1. Turn the power switch off.

    2. Inspect the VSC OFF switch (integration control and panel assembly) Click here.

      OK
      The VSC OFF switch (integration control and panel assembly) is normal.

    NG

    REPLACE INTEGRATION CONTROL AND PANEL ASSEMBLY Click here

    OK

  7. CHECK HARNESS AND CONNECTOR (BRAKE BOOSTER WITH MASTER CYLINDER ASSEMBLY - INTEGRATION CONTROL AND PANEL ASSEMBLY)


    1. Disconnect the A24 skid control ECU (brake booster with master cylinder assembly) connector.

    2. Disconnect the H71 VSC OFF switch (integration control and panel assembly) connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      A24-8 (CSW) - H71-7 (+) Always Below 1 Ω
      A24-8 (CSW) - Body ground Always 10 kΩ or higher
      H71-5 (E) - Body ground Always Below 1 Ω
      Result
      Result Proceed to
      OK (for LHD) A
      OK (for RHD) B
      NG C

      Tech Tips

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


    A

    REPLACE BRAKE BOOSTER WITH MASTER CYLINDER ASSEMBLY Click here

    B

    REPLACE BRAKE BOOSTER WITH MASTER CYLINDER ASSEMBLY Click here

    C

    REPAIR OR REPLACE HARNESS OR CONNECTOR