Operations

Control Module Inputs:

Control Module Bus Inputs:

The value from TCM is given for automatic transmission
The value is calculated in the engine management system for manual gearboxes
See also Bus and diagnostic communication, Technical data, Control module connections, refer to Powertrain Management.

Control Module Outputs (Part 1 Of 2):

Control Module Outputs (Part 2 Of 2):

Control Module Bus Outputs:

See also Bus and diagnostic communication, Technical data, Control module connections, refer to Powertrain Management.






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 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.

Power Supply

Battery voltage (+30 circuit)





+30 voltage goes via fuse 2 (342a) to pins 17 and 18 on the control module.

Battery voltage (+15 circuit)
+15 voltage goes via fuse 19 (22a) to pin 15 on the control module. When the +15 voltage is applied to pin 15, the control module is activated.


Diagnostics
If the voltage drops below 9 V DC for at least 0.5 seconds at vehicle speeds above 6 km/h (3.7 mph), diagnostic trouble code C1532 will be generated and the TCS and ABS functions will be disengaged at the same time as the warning lamps for ABS, brake fluid, central warning and TCS OFF go on.


Control module ground





The control module is grounded via pin 19 to grounding point G2. The pump motor is grounded through pin 16 to grounding points G30 and G40 (G42 RHD).


Diagnostics
If there is a break in the circuit to pin 19, 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. Communication with the diagnostic tool is not possible.
If there is a break in the circuit to pin 16, diagnostic trouble code C2465 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.