1993 Pontiac Trans Sport Owner's Manual - Page 151

Your Driving and the Road Anti-Lock Brakes (CONTJ This light on the instrument panel will go on when you start your vehicle. Your anti-lock brake system has a twopart system check: * When you start your vehicle and begin to drive away you may hear a momentary motor or clicking noise and you may even notice that your brake pedal moves a little while thisis going on. This is theABS system testing itself. (You may also hear this noise if you leavethe ignition in the Run position for about four seconds before starting the vehicle.) If you have yourfoot on the brake pedal, this checkwon't happen until the vehicle goes about4 mph (6 krn/h) m m m or until you take your foot off the brake pedal. After an ABS stop, you may hear a clicking noise the next time the vehicle goes about4 mph (6 km/h). If there's aproblem with the anti-lock brake system, the anti-lock brake system warning light will stay on or flash. See the Index under Anti-Lock Brake System Warning Light. Here's how anti-lock works. Let'ssay the road is wet. You're driving safely. Suddenly ananimal jumps out in front of you. You slam on the brakes. Here's what happens with ABS. A computer senses that wheels are slowing down. The computer separately works the brakes at each front wheel and at the rear wheels. The anti-lock system can change the brake pressure faster than any driver could. The computer is programmed to mpke the most of available tire and road conditions. 150