Electronically Controlled Brake System
BRAKE CONTROL: ELECTRONICALLY CONTROLLED BRAKE SYSTEM: PRECAUTION
NOTICE:
When disconnecting the cable from the negative (-) battery terminal, some systems need to be initialized after the cable is reconnected Repair Instruction - Initialization.
1. TROUBLESHOOTING PRECAUTIONS
(a) When there is a malfunction with terminal contact points or a problem with part installation, 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 this system may be influenced by malfunctions in systems other than the brake control system, be sure to also check for DTCs in other systems.
2. HANDLING PRECAUTIONS
(a) Do not remove or install the electronically controlled brake system parts such as the steering angle sensor, yaw rate sensor or brake pedal stroke sensor except when required, as they need to be adjusted correctly after removal and installation.
(b) Be sure to complete preparation before work and confirmation after work by following the directions in the repair manual when working on the electronically controlled brake system.
(c) Be sure to remove and install the skid control ECU, brake actuator, brake accumulator pump, each sensor, etc. with the engine switch off unless otherwise specified in the inspection procedure.
(d) Be sure to remove the 2 main relays before removal and installation, or replacement of the electronically controlled brake system parts.
(e) The removal and installation of the brake actuator, brake accumulator pump, master cylinder or stroke simulator as well as other procedures can cause the fluid level to drop below the fluid reservoir port. If this happens when performing such work, be sure to remove the 2 connectors of the brake accumulator pump before the bleeding of the air in the pipeline is completed.
HINT
* When the pump motor is operated with the air in the brake actuator hose, bleeding of the air becomes difficult due to the air in the actuator.
* The skid control ECU may operate the stroke simulator and drive the pump motor even when the engine switch is turned off.
* Even with the engine switch turned off, the skid control ECU can be operated for 2 minutes after the brake operation is finished.
(f) When removing the main relay and motor relay:
(1) With the engine switch off and the driver door closed, wait for 2 minutes without depressing the brake pedal. Make sure the brake control system is off. Then remove the 2 relays.
HINT
Just before the brake control system turns off, the pump motor will operate for several seconds to prepare for its next operation.
(g) When removing and installing the skid control ECU, brake actuator, brake accumulator pump and each sensor, be sure to check that the normal display is output in the Test Mode inspection and in DTC output inspection after installing all the parts.
3. DTC PRECAUTION
(a) Warnings for some DTCs cannot be cleared only by repairing the malfunctioning parts. If the warning is displayed after repair work, the DTC should be cleared after turning the engine switch off.
NOTICE:
If a part is still malfunctioning even after the DTC is cleared, the DTC will be stored again.
4. CHASSIS DYNAMOMETER PRECAUTION
(a) Disable TR(A)C and VSC control when using chassis dynamometer.
When testing with a drum tester such as a speedometer tester, a combination tester for the speedometer and brake, a chassis dynamometer, or when jacking up the rear wheels and turning the wheels, enter the "Inspection Mode" with the Techstream and change to traction control off mode and VSC system off mode.
CAUTION:
If the vehicle is tested in normal mode on the drum tester, the traction control and VSC system may cause the vehicle to jump out from the drum tester.
NOTICE:
* Check that the multi-information display shows the TR(A)C OFF display.
* Check that the VSC OFF indicator light illuminates on the combination meter.
* For safety, secure the vehicle with restraint chains while using a drum tester.
* When performing procedures related to VSC OFF switch operation, make sure the mode is VSC OFF mode.
5. CAN COMMUNICATION SYSTEM PRECAUTION
(a) The CAN communication system is used for the data communication between the skid control ECU, the steering angle sensor, the yaw rate and acceleration sensor and other ECUs. If there is trouble with the CAN communication line, corresponding DTCs in the communication line will be output.
(b) If the DTC in the CAN communication line is output, repair the malfunction in the communication line and troubleshoot the electronically controlled brake system while data communication is normal.
(c) Since the CAN communication line has a specific length and route, it cannot be repaired temporarily with a bypass wire, etc.
6. PRECAUTIONS WHEN USING TECHSTREAM
(a) When using the Techstream with the engine switch off to troubleshoot: Connect the Techstream to the vehicle, and turn a courtesy light switch on and off at 1.5 seconds intervals until communication between the tester and vehicle begins.
(b) After all DTCs are cleared, check if the trouble occurs again 6 seconds after the engine switch is turned on (IG).
7. PRECAUTIONS WHEN REPLACING SKID CONTROL ECU (INTERNAL GATEWAY ECU) WITH ANOTHER VEHICLE'S ECU OR WHEN CHANGING OPTIONAL EQUIPMENT
Using Techstream:
(a) When replacing the skid control ECU (internal gateway ECU) with another vehicle's ECU, check the optional equipment which uses CAN communication of the other vehicle.
HINT
In the gateway ECU, there is information on the optional equipment which uses CAN communication. If the optional equipment of the original ECU and ECU that was used in the other vehicle are different, it is necessary to initialize the ECU that was used in the other vehicle with Techstream to clear the optional equipment information. If not initialized, a DTC may be output.
(1) Connect the Techstream to the DLC3.
(b) If the optional equipment is different than the other vehicle, initialize the skid control ECU (internal gateway ECU).
(1) Connect the Techstream to the DLC3. Menu: Body Electrical.
(2) Select the following item from the System Select Menu: Body Electrical.
(3) Select either of the following items: ECM Gateway, ECB* Gateway or Gateway (main body ECU).
HINT
*: Electronically controlled brake
(4) Select the following item from the Utility Selection Menu: Initialization.