ABS Control Module With TRACS / STC

ABS Control Module With TRACS (Traction Control System)/STC (Stability And Traction Control)





The control module for ABS with TRACS/STC also contains two micro-processors and the four outlet valves and four inlet valves used in the standard ABS control module. The difference (software aside) is that the control module has two extra valves. One valve (Separation Valve-SV) separates the master cylinder from the brake circuit. The other valve (Hydraulic Shuttle Valve-HSV) opens the connection to the brake fluid reservoir during traction control.

ABS control module with DSTC (dynamic stability and traction control)





The ABS control module with DSTC has twelve valve coils for the hydraulic valves, of which four are outlet valve coils, four are inlet valve coils, two are used for traction control and two more are for DSTC. When replacing the ABS control module in a car with DSTC, the control module must be calibrated according to the instructions for VADIS vehicle communication or manually via a test drive.
Configuring the control module
From model year 2000 the ABS control module with DSTC is factory programmed with software for several models. The central electronic module (CEM) provides information about the car configuration on the Controller Area Network (CAN) in the car. The ABS control module for DSTC reads the information and uses it for configuration during the first ignition cycle.

ABS hydraulic modulator





The ABS hydraulic modulator is located in the engine compartment.
The ABS hydraulic modulator consists of a pump motor and the hydraulic valves which control the pressure to the different hydraulic brake circuits. During ABS control these valves limit the brake pressure to each wheel individually to prevent the wheels from locking. If necessary the valves operate with the hydraulic pump. During stability and traction control the pump and valves combine to supply brake pressure.
There are diagnostics for the pump motor.

Note: The illustration shows the hydraulic modulator for ABS and ABS with TRACS/STC. The hydraulic modulator for ABS with DSTC looks slightly different. The pump motor connector is integrated in the ABS hydraulic modulator.