With ABS/TCS

MUTUAL COMMUNICATION
The Anti-Lock Brake System/Traction Control System (ABS/TCS) allows for mutual communication between the two systems.
1. The ABS consists of electronic and hydraulic components. It allows for control of the braking force so locking of the wheels can be avoided.
a. Improves proper tracking performance through steering wheel operation.
b. Eases obstacle avoidance through steering wheel operation.
c. Improves vehicle stability.
2. The TCS controls engine torque via throttle and fuel-cut control systems and A/T shift schedule, preventing the drive wheels from spinning. This, in turn, prevents the vehicles rear end from skidding to either side, resulting in improved starting ability, acceleration, as well as overall vehicle stability.





Anti-Lock Brake (ABS) Operation
^ When the vehicle speed is less than 10 km/h (6 MPH) this system does not work.
^ The Anti-Lock Brake System (ABS) has a self-test function. The system turns on the ABS warning lamp for 1 second each time the ignition switch is turned "ON". After the engine is started, the ABS warning lamp turns off. The system performs a test the first time the vehicle reaches 6 km/h (4 MPH). A mechanical noise may be heard as the ABS performs this self-test. This is a normal part of the self-test feature. If a malfunction is found during this check, the ABS warning lamp will stay on.
^ While driving, a mechanical noise may be heard during ABS operation. This is a normal condition.





Traction Control System (TCS) Operation
This system has a secondary throttle valve which is opened/closed by a throttle motor. This is in addition to the primary throttle valve linked to the accelerator pedal. The opening angle of this valve is feed-back controlled by the secondary throttle sensor. The secondary throttle valve is normally kept in the fully opened position. When a slip of the drive wheels is detected by the wheel sensor, the TCS control unit determines the optimum opening position of the secondary throttle valve. The Throttle Actuator Control (TAC) Module then closes the secondary throttle valve to the correct position according to this information. It then reduces the engine output torque, and so avoids occurrence of slip. At the same time, a signal sent from the TCS control unit allows the ECM to cut fuel supply. The TCS control unit needs the primary throttle valve position signal to determine the secondary throttle valve opening position. The TAC module receives the throttle sensor position signal through the ECCS control module (ECM), and the TAC module sends the signal to the TCS control unit. If the TAC module detects trouble in the throttle valve control system, it de-energizes a relay located up-stream of the throttle motor power supply. The secondary throttle valve is then opened fully by means of a return spring. In this case, ordinary vehicle operation is assured by the functioning of the primary throttle valve. At the same time, the TAC module stops sending the throttle position sensor signal to the TCS control unit.





Secondary Throttle Fully-closed Position Self-Learning Control
When a certain condition occurs with ignition switch ON, the TAC module checks for operation of the throttle control system. It does this by fully closing the secondary throttle and then opening it fully. Simultaneously, the TAC module reads the secondary throttle position sensor output values at both the fully closed/opened positions. This data is used for self-diagnosing the secondary throttle driving system. The same data is also used for improving the control accuracy of the secondary throttle. This learning control is performed at the moment the ignition switch is turned "ON" under the following conditions:
^ The automatic transmission is set in "N" or "P" position.
^ The accelerator pedal is released completely.