ELECTRONICALLY CONTROLLED BRAKE SYSTEM TRC does not Operate

DESCRIPTION

When ABS, TRC or VSC is operating, the skid control ECU (brake booster with master cylinder assembly) blinks the slip indicator light to inform the driver that slippage occurred.

When in VSC off mode, or TRC and VSC are disabled, the multi-information display in the combination meter assembly displays "Traction Control Turned Off" and the VSC OFF indicator light illuminates to inform the driver.

When a communication malfunction with the ECM is detected, TRC and VSC are disabled. Also when the system is malfunctioning, TRC and VSC are disabled and the indicator lights of related systems illuminate.

CAUTION / NOTICE / HINT

Note

When replacing the skid control ECU assembly, perform initialization and calibration of the linear solenoid valve.

Click here

PROCEDURE


  1. BRAKE PROBLEM CHECK


    1. Check if the slip indicator light was illuminated when TRC did not operate.

      OK
      The slip indicator light was illuminated.

      Tech Tips

      When a DTC is stored, the slip indicator light is illuminated and TRC does not operate due to the fail-safe function.

    2. Check the operation condition of the VSC OFF switch (No. 2 combination switch assembly) when TRC did not operate.

      OK
      The VSC OFF switch (No. 2 combination switch assembly) had been operated to turn off TRC when TRC did not operate.

      Tech Tips

      When the multi-information display in the combination meter assembly displays "Traction Control Turned Off", TRC does not operate.

      Result
      Proceed to
      OK
      NG

    OK

    END

    NG

  2. CHECK DTC


    1. Clear the DTCs.

      Click here


      Chassis > ABS/VSC/TRC > Clear DTCs

    2. Turn the engine switch off.

    3. Turn the engine switch on (IG).

    4. Check the DTCs (electronically controlled brake system) that are output.

      Click here


      Chassis > ABS/VSC/TRC > Trouble Codes
      Result
      Result Proceed to
      DTCs are not output. A
      Electronically controlled brake system DTCs are output. B

    B

    REPAIR CIRCUITS INDICATED BY OUTPUT DTCS Click here

    A

  3. CHECK VEHICLE


    1. Operate the VSC OFF switch (No. 2 combination switch assembly) and check that the multi-information display in the combination meter assembly displays "Traction Control Turned Off" and the VSC OFF indicator light illuminates in accordance with the operation of the switch.

      OK
      The multi-information display in the combination meter assembly displays "Traction Control Turned Off" and the VSC OFF indicator light illuminates in accordance with the operation of the switch.
      Result
      Proceed to
      OK
      NG

    NG

    INSPECT VSC OFF SWITCH CIRCUIT Click here

    OK

  4. PERFORM TEST MODE (SIGNAL CHECK) INSPECTION (SPEED SENSOR CIRCUIT)


    1. Using the GTS, perform a Test Mode (Signal Check) inspection sensor check and check that speed sensor Test Mode (Signal Check) inspection items change from incomplete to complete.

      Click here


      Chassis > ABS/VSC/TRC > Utility
      Tester Display
      Signal Check
      OK
      Speed sensor Test Mode (Signal Check) inspection items change from incomplete to complete.
      Result
      Proceed to
      OK
      NG

    NG

    INSPECT AND REPAIR MALFUNCTIONING SPEED SENSOR CIRCUIT

    OK

  5. PERFORM OPERATION CHECK DRIVING


    1. Operate the VSC OFF switch (No. 2 combination switch assembly) and check that the system is not in TRC off mode or VSC off mode.

    2. Check that no DTCs are output and that each warning light is not illuminated.

    3. Start off the vehicle on a low friction surface and check that TRC operates when attempting to make the drive wheels slip.

      OK
      TRC operates when slip occurs when starting off.

      Note


      • Even when the system is normal, VSC may not operate when the vehicle speed is low or TRC may not operate due to a malfunction. Make sure that only the drive wheels slip during the procedure.

      • When confirming that the slip indicator light blinks, do not slip the drive wheels longer than necessary. Whether TRC operated or not can be checked by reading the Freeze Frame Data when the system operated.

      • Pay attention to your surroundings when performing the procedure and depress the accelerator pedal with caution.

      Result
      Proceed to
      OK
      NG

    OK

    USE SIMULATION METHOD TO CHECK Click here

    NG

    REPLACE SKID CONTROL ECU ASSEMBLY for RHD: Click here
    REPLACE SKID CONTROL ECU ASSEMBLY for LHD: Click here