Operation
Control module inputsABS 5.4 Control Mopdule Inputs:
^ Voltage (~30 circuit) (I).
^ Voltage (~15 circuit) (20).
^ Ground (G30, G2).
^ Wheel sensors, front (298RL, 298FR).
^ Wheel sensors, rear (298RL, 298RR).
^ Brake-light switch (29).
^ Data link (445).
Control module outputs
ABS 5.4 Control Module Outputs:
^ Wheel speed, FR (430).
^ Wheel speed, RL (540).
^ Return pump (547).
^ ABS warning lamp on MIU (540).
^ Data link (445).
^ Wheel speed, FL (430/505/589/595).
ABS 5.4 Control Module Outputs:
^ Inlet valve, FL (547).
^ Outlet valve, FL (547).
^ Inlet valve, RR (547).
^ Outlet valve, FR (547).
^ Inlet valve, RL (547).
^ Outlet valve, RL (547).
^ Inlet valve, RR (547).
^ Outlet valve, RR (547.
Control module overview
ABS 5.4 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.
Turning the ignition switch to ON activates the control module. The control module causes the ABS lamp to come on as a function test. It goes out after 3-5 seconds if no faults are detected.
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.
Diagnosis
The control module monitors its own internal functions and the other ABS-system components.
In the event of an internal control module fault, diagnostic trouble code Ci605 will be generated and the ABS system disconnected at the same time as the ABS lamp, the brake fluid warning lamp and the central warning lamp come on.
ABS 5.4 Power Supply Diagrams:
Power supply
Battery voltage (+30 circuit)
Current (+30 circuit) is supplied to control module pins 17 and 18 via maxi fuse 2 (342a).
Battery voltage (+15 circuit)
Current (~15 circuit) is supplied to control module pin 15 via fuse 19 (22a). The control module will be activated when current (+15 circuit) is applied to pin 15.
Diagnosis
If the supply of current is below 9 V for at least 0.5 seconds at a vehicle speed above 6 km/h, diagnostic trouble code C1532 will be generated and the ABS system disconnected at the same time as the ABS lamp, brake fluid warning lamp and the central warning lamp come on.
ABS 5.4 Control Module Grounds:
Control module ground
The control module is grounded via pin 19 to grounding point G3.
The pump motor is grounded through pin 16 to grounding point G2.
Diagnosis
If there is an open circuit on pin 19, the ABS function will be disconnected at the same time as the ABS lamp, brake fluid warning lamp and central warning lamp come on. No communication with the diagnostics tool is possible.
If there is an open circuit on pin 16, diagnostic trouble code C2465 will be generated and the ABS function disconnected at the same time as the ABS lamp, brake fluid warning lamp and central warning lamp come on.