Antilock Brakes / Traction Control Systems: Service Precautions

BRAKE CONTROL / DYNAMIC CONTROL SYSTEMS: ELECTRONICALLY CONTROLLED BRAKE SYSTEM: PRECAUTION

1. TROUBLESHOOTING PRECAUTIONS

(a) 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.

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

(c) 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.

2. HANDLING PRECAUTIONS

(a) 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 except when required, as they cannot be adjusted correctly after removal or installation.

(b) 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.

(c) Be sure that the power switch is off when removing and installing the ECU, actuator, each sensor, etc. unless it is specified otherwise in the inspection procedure.

(d) If the brake booster with master cylinder (skid control ECU and brake actuator) 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 Techstream, also check that system functions and signals received by the ECU are normal using Test Mode.

(e) If the brake pedal is depressed before the brake control system is prepared to operate, the pedal stroke may seem unusually long or short. This is due to the fact the stroke simulator cut solenoid has not yet operated and is not a malfunction.

After the power switch is turned on (IG) or the brake pedal is depressed twice or more, the stroke simulator will operate and the brake pedal stroke will remain consistent.

3. DTC PRECAUTION

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

NOTICE:
If a DTC part is still malfunctioning even after the DTC is cleared, the DTC will be stored again.

4. CHASSIS DYNAMOMETER PRECAUTION

(a) Enter Inspection Mode to disable TRAC and VSC control when using a chassis dynamometer Component Tests and General Diagnostics.

NOTICE:
* Make sure that the slip indicator lights blink (Inspection Mode is activated).
* Secure the vehicle with a lock chain for safety.
* When performing procedures related to VSC OFF switch operation, make sure that the mode is VSC off mode.

5. CAN COMMUNICATION SYSTEM PRECAUTIONS

(a) The CAN communication system is used for the data communication between the skid control ECU, the steering angle sensor, yaw rate and acceleration sensor and other ECUs. If there are any problems in the CAN communication line, corresponding DTCs in the communication line are stored.

(b) If any CAN communication line DTCs are output, repair the malfunction in the communication line and troubleshoot the electronically controlled brake system when data communication is normal.

(c) 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.