Operation CHARM: Car repair manuals for everyone.

Vehicle Damage Warnings

General information

Control modules

Connecting disconnecting control modules






Always switch off the ignition before connecting or disconnecting a connector or the test box to a control module.






Temperature

The control module must not be heated to above 80° C. Remove control module when staving for example.

Arc welding

Disconnect connector from control modules when arc welding. Remove control module before carrying out any arc welding work close to it.

Replacing

Do not replace a control module without checking its wiring and components. The new component may be damaged in the same way as the old one.

Mechanical outline

Wheel bearings






Wheel bearings must be free of play. If there is too much play in bearings, this may affect signals from the wheel sensors to the control module, and cause wheel sensor DTCs to be posted.

Pulse wheel






It the pulse wheel is loose or damaged, this may affect signals from the wheel sensors to the control module, and cause wheel sensor DTCs to be posted.


Wheel sensors






If wheel sensors are loose or badly fitted, this can affect signals to the control module. Wheel sensors must be firmly in the correct position relative to the spindle/wheel shaft (sensor towards end position), otherwise wheel sensor DTCs may be posted.

Wheel stuck






It a wheel will not move or sticks when moving off or driving because the brakes are badly adjusted, sticking or frozen solid, this may cause wheel sensor DTCs to be posted.

Brake discs






In cars fitted with TRACS, the control module continuously monitors how much TRACS is used, and uses this data to calculate the estimated brake disc temperature (on the driving wheels).

If TRACS is used so much that there is a risk of overheating the brake discs, a DTC may be posted.