Vehicles With Automatic Traction Control (ATC)

Automatic Traction Control (ATC) is only on vehicles with front wheel drive.The function of automatic traction control requires that the control module - J104 - exchanges data with the engine and transmission control modules (i.e. control modules communicate with each other).

The communication link employs:
Transfer of data via CAN -Bus . The CAN-Bus consists of only two wires through which all necessary data is transferred.

Automatic traction control prevents the driven wheels from spinning (slipping) under acceleration by reducing engine performance. It is active over the total speed range. The EDL and ATC functions act together to assist acceleration.

With certain engine versions, ATC also incorporates an over-run torque-limiting function (MSR). MSR prevents the driven wheels from locking (skidding) due to excessive engine braking, e.g. when shifting down from 3rd to 2nd gear. The engine braking effect is reduced via idle speed control. Not all vehicles are equipped with MSR.

If required, ATC can be switched off and then on using the ATC push-button switch in the center of the instrument panel. The switch has no influence on the MSR. Automatic traction control is automatically self-activated the next time the ignition is switched on. When ATC is deactivated, the ATC warning light is switched on in the instrument cluster. During actual control operation, the indicator light flashes three times per second.





1-Warning lamp - K86
2-ATC push - button switch

Malfunction:
Indicator light does not light up when ATC is switched off via ATC switch.

Malfunction causes could be:
^ ATC switch faulty go to Electrical testing, Test Steps No. 17 and 18.
^ ATC warning light - K86 faulty go to Electrical testing, Test Steps No. 17 and 18.
^ Open circuit in wiring from contact 15 of control module -J104- to instrument cluster go to Test Steps No. 17 and 18. Electrical Test Table
^ Short circuit to positive in wiring from contact 15 of control module - J104 to instrument cluster go to Test Steps No. 17 and 18. Electrical Test Table

Automatic traction control indicator light lights up, after ignition is switched on and none of the above-mentioned complaints exist:

Malfunction cause could be:
Wiring from contact 15 of control module -J104- to instrument cluster (for activation of ATC indicator light) has a short to ground :go to Test Steps No. 17 and 18. Electrical Test Table

System, checking via indicator lights









1) only for vehicles with ATC

^ K14: Indicator light for parking brake
^ K47: Indicator light for ABS (right arrow)
^ K118: Indicator light for brake system (left arrow)
^ K155: Indicator light for ATC 1)





1) only for vehicles with ATC

CAUTION: After indicator light for ABS - K47 and brake warning light - K118 light up, the electronic brake regulation (EBV) is no longer functional and the rear wheels can lock up (skid) under light braking.