ELECTRONICALLY CONTROLLED BRAKE SYSTEM PRECAUTION


  1. PRECAUTION FOR DISCONNECTING CABLE FROM NEGATIVE AUXILIARY BATTERY TERMINAL

    Note

    When disconnecting the cable from the negative (-) auxiliary battery terminal, initialize the following system(s) after the cable is reconnected:

    System See Procedure
    Lane Departure Alert System (w/ Steering Control)

    Click here

    Parking Assist Monitor System (w/o Parallel Parking Assist Function)
    Pre-collision System
  2. TROUBLESHOOTING PRECAUTIONS


    1. When there is a malfunction with terminal contact points or part installation problems, removal and installation of the suspected problem parts may return the system to the normal condition either completely or temporarily.

    2. In order to determine the malfunctioning area, be sure to check the conditions at the time the malfunction occurred, such as DTC output and Freeze Frame Data, and record it before disconnecting each connector or removing and installing parts.

    3. Since the system may be influenced by malfunctions in systems other than the brake control system, be sure to check for DTCs in other systems.

  3. HANDLING PRECAUTIONS


    1. Do not remove or install electronically controlled brake system parts such as the steering angle sensor, yaw rate and acceleration sensor or brake pedal stroke sensor assembly except when required, as they need to be adjusted correctly after removal and installation.

    2. When replacing the skid control ECU assembly, always install a new one.

      Note

      Do not use a skid control ECU assembly from another vehicle (vehicle on display, etc.).

    3. Be sure to perform preparation before work and confirmation after work is completed by following the directions in the repair manual when working on the electronically controlled brake system.

    4. Be sure that the power switch is off when removing and installing the ECU, actuator, sensors, etc. unless it is otherwise specified in the inspection procedure.

    5. While the auxiliary battery is connected, even if the power switch is off, the brake control system activates when the brake pedal is depressed or the door courtesy light switch is turned on. Therefore during servicing of the brake system components, do not depress the brake pedal or open/close the doors while the auxiliary battery is connected.

    6. The removal or installation of the brake actuator assembly, brake master cylinder sub-assembly or brake stroke simulator cylinder sub-assembly as well as other procedures can cause the brake fluid level to drop below the outlet port of the fluid reservoir. If this happens when performing such work, be sure to remove the 2 ABS motor relays until the brake lines and brake actuator hose have been bled.

      Tech Tips


      • If the pump motor is operated while there is air in the brake actuator hose, bleeding the air becomes difficult due to air in the brake actuator assembly.

      • The skid control ECU assembly may operate the stroke simulator and drive the pump motor even when the power switch is off.

      • With the power switch off, the skid control ECU assembly may operate for 2 minutes after operating the brake pedal.

    7. Removal of the ABS motor relay


      1. Wait for 2 minutes after turning the power switch off, operating the brake pedal and closing the driver door before removing the relays.

        Tech Tips

        The skid control ECU assembly operates the pump motor just before the brake control system shuts down in order to prepare the system for the next time it is operated.

    8. If the skid control ECU assembly or a sensor has been removed and installed, it is necessary to check the system for problems after the parts have been reassembled. Check for DTCs using the GTS. Also check that the system functions and signals received by the ECU are normal using Test Mode.

  4. DTC PRECAUTION


    1. Warnings for some DTCs cannot be cleared by only repairing the malfunctioning parts. If the warning is displayed even after repair work, the DTC should be cleared after turning the power switch off.

      Note

      If a DTC for a malfunctioning part reappears after it is cleared, then it has been stored again.

    2. When 2 or more DTCs are detected, perform circuit inspections one by one until the problem is identified.

  5. CHASSIS DYNAMOMETER PRECAUTION


    1. Enter Inspection Mode or VSC off mode to disable TRC and VSC operation when using a chassis dynamometer.

      Refer to Inspection Mode Procedure: Click here

      Note


      • Make sure that the slip indicator light blinks (Inspection Mode is activated).

      • Secure the vehicle with lock chains for safety.

      • When performing a procedure related to VSC OFF switch (combination switch assembly) operation, make sure that the mode is VSC off mode.

  6. BRAKE TESTER PRECAUTION


    1. When inspecting the brakes using a brake tester, the braking force of the rear wheels may be reduced.

      When the vehicle speed is 0 km/h (0 mph), the brake control system of the vehicle limits the rear brake fluid pressure to approximately 50% of the normal brake fluid pressure when driving the vehicle, in order to reduce energy consumption.

  7. CAN COMMUNICATION SYSTEM PRECAUTIONS


    1. The CAN communication system is used for communication between the skid control ECU assembly, steering angle sensor, yaw rate and acceleration sensor and other ECUs. If there is a malfunction in a CAN communication line, corresponding DTCs for the communication line are output.

    2. If any CAN communication DTCs are output, repair the malfunction, then troubleshoot the VSC system while communication is normal.

    3. In order to enable CAN communication, a specific type of wiring is used for the CAN communication lines. The wiring used for each communication line is a twisted pair of wires that have an equal length. A bypass wire should not be used, because the data being transmitted will be corrupted.