Control module: Notes

The control module is integrated into the TC/ABS unit and has a 31-pin connector.

A wheel sensor at each wheel sends a wheel-speed signal to the control module.

ABS (Anti Block System) means that the solenoid valves (inlet/outlet valves) and the return pump govern the hydraulic brake pressure when one of the wheels has a greater retardation than the others. The hydraulic brake pressure can be kept constant or be reduced so that each wheel can attain maximum braking force against the road surface.

EBD (Electronic Brake-force Distribution) means that the control module distributes the braking force between the front and rear wheels through solenoid valves (inlet/outlet valves).

TCS (Traction Control System) means that the control module always utilizes maximum friction on the driving wheels during acceleration. A limited amount of wheelspin is modulated by braking and requesting torque limitation from Trionic. The control module activates the pressure increase valve and pressure relief valve as well as the return pump to create and govern pressure to the driving wheels that are to be braked during wheelspin exceeding a specified limit.

The control module is continuously powered from the +30 circuit and is adapted for a voltage of between 9 V DC and 16 V DC during operation.

When the ignition switch is turned to ON, the control module is activated and the ABS, TCS OFF and TCS lamps come on as a function test. They go out after 3-5 seconds if no faults are present in the systems.

Always ground yourself, e.g. on the engine block, before touching the control module and avoid touching the terminal pins.

The control module incorporates the following components:

• Main relay
• Pump relay