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Control module

Control module


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.

The ABS (Anti Block System) function entails the solenoid valves (inlet/outlet valves) and the return pump modulating the hydraulic brake pressure whenever the retardation of one of the wheels is greater than the others. The hydraulic brake pressure can be maintained at a constant level or reduced so that each wheel is able to employ maximum braking force from the road surface.

EBD (Electronic Brake force Distribution) entails the control module governing the distribution of the braking force between the front and rear wheels using solenoid valves (inlet/outlet valves).

The TCS (Traction Control System) function entails the control module always utilizing maximum friction for the driving wheels during acceleration. A limited wheelspin can be modulated using the brakes and a request to Trionic for engine torque limitation. The control module activates the pressure increase valve, pressure relief valve and return pump to create and govern the pressure to the driving wheel to be braked when the wheelspin exceeds the permitted 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


Main relay

The integral main relay supplies power to the solenoid valves and pump relay and cannot be replaced separately.

Pump relay

The integral pump relay supplies power to the return pump and cannot be replaced separately.

Diagnostics

The control module monitors its own internal functions as well as the components of the TC/ABS system.

If an internal fault occurs in the control module, diagnostic trouble code C1605 will be set, the TCS and ABS functions will be disabled, and the warning lamps for ABS, brakes, and TCS OFF will light up as well as the central warning lamp.