Brake Abs Warning Light problems of the 1999 Chevrolet Lumina

Concern: 1999 low mileage Chevrolet Lumina. Problems with the abs and traction control systems. Corrosion or defective wheel sensors can cause total loss of braking at slow speeds. My customer explained that his abs light was on for several months. He had driven threw his fence after turning into his driveway. He mentioned that he would lose all braking if the traction control and abs light came on at the same time, the abs and traction control unit was actuating. It was my understanding that if the abs light was on in all vehicles the abs would drop out of the braking system rendering the vehicle with conventional brakes. I guess this is not true with some late model gmã‚s. I have learned that diagnosing intermittent wheel sensors and wiring is a daunting task. The vehicle we worked on had a defective right front wheel sensor. We scoped the signal from the sensor and it showed perfect amplitude, voltage and wave form. Further testing showed it read open with an ohmmeter. Unless the circuit is completely open or shorted testing the wheel sensors and wiring with an ohmmeter or a scope is useless at times. In the past following a gm trouble code flow chart was useless, the fix was to rewire and replace the suspect parts. . I feel that gm should recall these vehicles. Or at least offer the replacement parts including a reprogrammed traction control/abs controller at a reasonable price. Searching the archives I found one other late model gm with the same type of problems and loss of low speed braking. 1997 pontiac grand am engine: 2. 4 l / 146 cid / 4 cyl / gas / dohc fuel: fuel injection ignition: distributorless trans: 4-speed automatic transaxle (electronic) mileage: 95,000 mi VIN: 1g2ne52t9vc861506 time. Today customer comes in with a complaint of clicking, loss of pedal, and no stop. Customer was in today we got the abs to actuate and he said thats what it was doing.