Questions and Answers

Pontiac Firebird Trans Am ABS Light On Q. Vince, The ABS Inoperative light functions as intended when starting the car up. However, after driving a tenth to a quarter mile, the light will come back on and stay on until the car is turned off. Speed and brake pedal application do not affect when the light comes on. I have put an ohm meter on each sensor and the wiring.

The resistance is equal on all three sensors and the wires running to the controllers. I have also cleaned the differential, differential speed sensor and changed the differential fluid. Running the vehicle at various speeds and lengths of time with the rear wheels off of the ground does not cause the ABS Inoperative light to activate.

Any suggestions?? This problem began after a muffler shop welded in a catalytic converter. Car has a single converter located on passenger side under the floorboard.

• 1995 Pontiac Firebird Trans Am
• 5.7 Liter LT1
• Automatic transmission
• 78,000 miles

Thanks,
Tom

A. You need to have the system scanned for diagnostic trouble codes. When that light comes on there should be something stored in the ABS module to help in diagnosing the problem.

Once we know what the code is, we will have a place to start troubleshooting.