TCS Traction Control System
The TCS traction control system also known as ASR is used to prevent wheel spin and loss of traction. These systems control wheel spin during acceleration and are typically an add on to the ESC electronic stability control system. The TCS system controls and restores traction on slippery surfaces.
The ABS, ESC, and TCS systems share the same WSS wheel speed sensors. The TCS program also requires two additional solenoids in the hydraulic modulator assembly. These additional solenoids isolate the brake circuits to the drive wheels from the non-drive wheels during wheel spin. An electric pump and accumulator are used to apply the wheel brake on the wheel that has lost its traction. If one of the wheels were to loose traction, the pressurized fluid is used to apply the brakes on the wheel that is spinning.
These systems use an actuator to reduce power at speeds above 30mph by closing the throttle on vehicles with electronic throttle controls, retarding timing, or decreasing fuel injector pulse width. This not only helps the vehicle regain traction but also helps to prevent damage and overheating of the brake system. They utilize 4 channel ABS wheel speed sensor systems. This just means that there is a wheel speed sensor for each wheel.
The system includes an indicator light that flashes while the system is active or the vehicle is loosing traction. In most systems, the flashing amber light is a normal response and there is nothing for the customer to be concerned. It is used to inform the driver the system is active because these systems react so fast the driver is often unaware the wheel is beginning to spin and vehicle is losing traction. If the ABS and traction control light illuminates continuously, then the system should be scanned for any related codes. Most of these systems have a deactivation switch if traction control is not desired, for instance in deep snow.
