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Control module

Control module


The control module is an integral part of the ABS unit and has a 26-pin connector.

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

The ABS functions such that if the speed of a wheel is retarded more than that of the other wheels, the solenoid valves and return pump modulate the hydraulic brake pressure. The pressure can either be held constant or be reduced to enable the maximum braking effect to be achieved by each individual wheel on the prevailing road surface.

The EBD function incorporated in the control module controls the distribution of the brake force between the front and rear wheels by means of solenoid valves.

The control module receives a continuous power supply from the +30 circuit and is designed for a working voltage of between 9 and 16 V.

When the ignition key is turned to ON, the control module is energized and the ABS warning light comes on as part of the function test. If the system is OK, the light will go off after 3-5 seconds.

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 and the other ABS-system components.

If an internal fault occurs in the control module, diagnostic trouble code C1605 will be generated, the ABS warning light will come on and the ABS system will be disabled.