TCS

TRACTION CONTROL SYSTEM (TCS) DESCRIPTION (IF EQUIPPED)
The Traction Control System is available on this vehicle. The main purpose of traction control is to reduce wheel slip and maintain traction at the driven wheels when road surfaces are wet or snow covered. The traction control system reduces wheel slip by braking the wheel that is losing traction. The system is designed to operate at speeds below 56 km/h (35 mph).

The Controller Antilock Brake (CAB) monitors wheel speed. If during acceleration the CAB detects front (drive) wheel slip and the brakes are not applied, it will enter traction control mode. The CAB performs the traction control function in the following sequence:
1. Closes the (normally open) isolation valves.
2. Starts pump/motor to supply volume/pressure to front hydraulic circuits (pump runs continuously during traction control).
3. Opens and closes build and decay valves to maintain minimum wheel slip and maximum traction.

The cycling of the build and decay valves works similarly to ABS except that they work to control wheel spin by applying brakes. ABS function is to control wheel skid by releasing brakes.

Two pressure relief valves allow pressure/volume to return to the reservoir when not consumed by the build/decay cycles. These are required because the pump supplies more volume than the system requires. -

If at any time the brakes are applied during a traction control cycle, the brake switch will trigger the CAB to switch off the traction control.

The traction control system will be enabled at each ignition cycle. It may be turned off by depressing the traction control switch. The traction control system function indicator will illuminate immediately upon depressing the traction control switch button. The indicator will flash during a traction control cycle. If the controller calculates that the brake temperatures are high, the traction control system will become inoperative until a time-out period has elapsed. When in this thermo protection mode, the traction control indicator will illuminate; however, a fault will not be registered.