ANTI-LOCK BRAKE SYSTEM DIAGNOSIS SYSTEM

  1. DESCRIPTION

    When troubleshooting a vehicle with a diagnosis system, the only difference from the usual troubleshooting procedure is connecting the GTS to the vehicle and reading various data output from the skid control ECU (brake actuator assembly).

    The skid control ECU (brake actuator assembly) records DTCs when it detects a malfunction in itself or in its circuits.

    To check for DTCs, connect the GTS to the DLC3 on the vehicle. The GTS can be used to clear the DTCs, activate various actuators, and check the Freeze Frame Data and Data List.

    1. Check the battery voltage.

      Standard Voltage

      11 to 14 V

      If the voltage is below 11 V, recharge the battery before proceeding to the next step.

    2. Check the DLC3.

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  2. DIAGNOSIS

    1. If the skid control ECU (brake actuator assembly) detects a malfunction, the ABS warning and/or brake warning lights will come on in order to warn the driver.

    2. DTCs are simultaneously stored in memory. The DTCs can be read by connecting SST between terminals TC and CG of the DLC3 and observing the blinking pattern of the ABS warning light, or by connecting the GTS.

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    3. This system has a Test Mode (signal check) function.

      The DTCs can be read by connecting SST between terminals TS and CG of the DLC3 and observing the blinking pattern of the ABS warning light, or by connecting the GTS.

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  3. WARNING LIGHT INITIAL CHECK

    1. Release the parking brake.

      Note:

      Before releasing the parking brake, use wheel chocks to secure the vehicle.

      Tip:

      When the parking brake is applied or the brake fluid level is low, the brake warning light comes on.

    2. When the ignition switch is turned to ON, check that the ABS warning and brake warning lights come on for approximately 3 seconds.

      Tip:

      • If the warning light and indicator light check result is not normal, proceed to troubleshooting for the ABS warning and brake warning light circuits.

      • If any of the indicators remains on or does not come on, proceed to troubleshooting for the light circuits listed below.

      Trouble Area

      See Procedure

      ABS warning light circuit (Remains on)

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      ABS warning light circuit (Does not come on)

      Click here

      Brake warning light circuit (Remains on)

      Click here

      Brake warning light circuit (Does not come on)

      Click here