The 2002 Grand Prix came with a safety feature known as anti-lock brakes. Anti-lock brakes use individual sensors on the wheels that record and calculate wheel speed. These sensors report to the main anti-lock brake module and ultimately keep the brakes from locking if they are applied suddenly or in poor driving conditions. These sensors are connected to the wheel, or to the brake assembly on the wheels. Wires run from the sensors to the ABS control module via a plastic wiring harness. If the ABS warning light goes off on the dash, first the wheel that is giving the warning has to be identified. Once you do that, the wiring harness and the sensor need to be checked.
Instructions
- 1
Drive the Grand Prix to an auto parts store and have a diagnostic test run to determine which wheel sensor is triggering the ABS warning light. The diagnostic is free and does not take long.
2Have the attendant run the trouble codes from the diagnostic test through the computer system. This will pinpoint the faulty wheel sensor, and may be able to tell you whether the sensor itself is bad or whether there is an electrical short in the wiring system.
3Bring the vehicle home and use a jack to jack up the wheel where the faulty wheel sensor is. Lower the vehicle onto a jack stand.
4Use a lug wrench to remove the lugs and wheel.
5Slide underneath the Grand Prix and disconnect the plastic wiring harness from the sensor. To disconnect the harness, squeeze in on the two tabs on each side and then pull it out firmly.
6Connect the test light sensors to the plastic wiring harness. If the test light comes on, it means the wiring harness is good and that the problem is with the actual speed sensor itself.
