GM Service Manual Online
For 1990-2009 cars only

The purpose of the Delco Bosch 5.3 Antilock Brake System (ABS) is to minimize wheel slip during heavy braking. The Delco Bosch 5.3 performs this function by monitoring the speed of each wheel and controlling the brake fluid pressure to each wheel independently during a braking event. This allows the driver to retain directional stability and better steering capability.

The optional Traction Control System (TCS), option code NW9, also monitors rear wheel speeds and compares the rear wheel speeds to the speed of the front wheel speeds. If excessive front wheel speed is detected in either front wheels the TCS will be activated. The TCS uses the following to improved traction and vehicle stability:

    • Engine fuel control
    • Engine timing control
    • Front brake intervention

The optional Vehicle Stability Enhancement System (VSES) , option code JL4, monitors wheel speeds, lateral acceleration, and steering sensor inputs to determine a desired yaw rate. This desired yaw rate is compared to the actual yaw rate. The VSES tries to bring the values into agreement by selectively applying the front brakes.