1996 Mercury Cougar Owner's Manual - Page 172

During the Traction AssistTM function, which most often occurs during low speed acceleration on slippery surfaces, a noise may be heard coming from the engine compartment. This noise is created by the ABS pump and is normal and may last for a few seconds during the acceleration of the vehicle. In general, this system improves your vehicle's stability and acceleration performance when road conditions warrant. Traction AssistTM is fully effective up to approximately 25 mph (40 km/h). At 25 mph (40 km/h) the function begins to taper off until it no longer operates above 34 mph (55 km/h). If the Traction AssistTM system is cycled excessively, the system will shut down to prevent the rear brakes from overheating. During this shutdown period, the word OFF in the traction assist switch will be illuminated showing that the traction assist system is inoperative. A cooling down period is required to prevent damage to the rear brakes. This time period varies and depends on brake usage during the cooling down period. Anti-Lock braking is not affected and will function normally during the cool down period. NOTE: Traction-Lok axles are not an available option on vehicles equipped with traction assist. 172