Electronic Brake Control Module: Description and Operation

ABS/TCS CONTROL UNIT

The malfunction information related to ABS or ABS/TCS is transferred through the CAN communication line from ABS actuator and electric unit or ABS/TCS control unit to ECM.





The control unit computes the wheel rotating speed by the signal current sent from the sensor. Then it supplies a DC current to the actuator solenoid valve. It also controls ON-OFF operation of the valve relay and motor relay. If any electrical malfunction should be detected in the system, the control unit causes the warning lamp to light up. In this condition, the ABS will be deactivated by the control unit, and the vehicle's brake system reverts to normal operation.

Be sure to erase the malfunction information such as DTC not only for ABS actuator and electric unit or ABS/TCS control unit but also for ECM after the ABS or ABS/TCS related repair.

ABS/TCS COMMUNICATION LINE

This CAN communication line is used to control the smooth engine operation during the ABS or TCS operation. Pulse signals are exchanged between ECM and ABS actuator and electric unit or ABS/TCS control unit. Be sure to erase the malfunction information such as DTC not only in ABS actuator and electric unit or ABS/TCS control unit but also ECM after the ABS or ABS/TCS related repair.

TCS Function
Drive wheel slippage is detected by the 4-wheel rotating speed signal. When the wheel slip becomes excessive, the TCS operates, causing the SLIP indicator lamp to flash. And, at the same time, fuel-cut and throttle opening signals are sent to the ECM and a signal requiring a change in the shift schedule is sent to the TCM. When the TCS OFF switch is used to cancel TCS function, the TCS OFF indicator lamp will light. (TCS does not activate.) In case of a malfunction in the TCS, both the SLIP indicator lamp and the TCS OFF indicator lamp will light, while shutting down the TCS system operation. The vehicle will operate in the same way as a vehicle not equipped with the TCS.