ABS & Traction Control Lights on

[Wrj47]

Anti lock brake light and traction control light come on when starting car.

2000 Regal GSE - The anti-lock brake light and traction control light come on when starting car. This happens intermitently. The next time I start the car it doesn't come on. Then it will come on at a later time when starting the car. The car has 97000 miles. Assistance in identifying the problem will be appreciated.

[gmtech1]

To start, we will need the ABS code(s) posted. They must be read with a scanner capable of reading ABS codes. A basic OBDII code reader will not read ABS codes.

[Koscoe]

This sounds like a wheel speed sensor issue or the wires that lead into the sensor. Like gmtech1 said, you will have to get it scanned at a garage. Once you find out what wheel is out check out the wires really good. MY Grand Prix did have this issue. The wires were not broke all of the way through, but just enough where the sensor would pick up a signal some of the time and the other time make the lights come on. If the wires appear to be ok, then you will have to replace the hub becasue the sensor is integrated into the hub. Not too awful expensive or hard to replace. Let us know the results. If you need to replace the hub, RockAuto has good prices on these.

[mn_1]

If you buy a hub get the Timkin. They cost more but the cheapies dont last very long.

[012620]

Originally Posted by mn_1

If you buy a hub get the Timkin. They cost more but the cheapies dont last very long.

I agree with this statement. I tried a cheaper bearing but after a year I had to replace the bearing. I replace the cheap one with a Timkin Bearing I picked up on Amazon and at that time it did not cost that much more then the cheap bearing. Timkin is also USA made.

[Tech II]

I agree......there was a time these cheap bearings were being replaced just within months of each other......finally shop stopped selling them, because they were warranted, but we were eating the labor.....

But you need to read codes, to know which wheel speed circuit is at fault.....sometimes due to water intrusion, the harness AND bearing have to be replaced....

[jerroldk]

Hey guys, I've got the same yr make and model car with higher mileage. It has the same issue (Anti-Lock and Trac Off lights lit while running). When it began a number of weeks ago it was intermittent, but are on all the time now. I saw this post and decided to take it to a shop where they had a nice scanner. The ABS code (C1225/1232) was for a driver side speed sensor. He cleared the code and it came right back so we knew that was it.

I looked over all of the wiring for problems from the connector at the sensor through to the main wiring harness and saw no issues. So my question is, does this mean that the sensor inside the bearing is bad. They were National brand that I installed not two years back. Assuming the passenger side sensor is good due to the scan, for grins I checked the resistance across each speed sensor (passenger and driver side). They both yielded a value of 0.8. I also check the resistance on the leads leading back through the main harness to the control system for both sides. They too both matched at 1.8. I have no idea what these resistance values should read and am not even sure if checking for resistance will really tell me anything as to the condition of the sensor.

Does anyone have any valuable input for me here? I just don't want to drop the money for a new bearing to actually still have a wiring issue I never found.

[Tech II]

When the light is on constant, it is usually easy to diagnose....

In the GM shop I worked in, you would attach a scanner, see what the code is, and usually just driving in the parking lot and looking at data, more often than not, you got a zero reading for speed on that circuit....every GM tech had an old bearing on hand(usually removed because the bearing made noise, but the sensor was ok).....so with the scan tool on, you would rotate the bad wheel, and see zero....then you would just disconnect the harness from the bearing and attach it to your "test" bearing....you spin it and if you now see speed data, you know the bearing is bad....a very quick diagnosis.......also you would move the harness around as you spin the test bearing to see if it affects the reading......

The resistance reading of the harness means absolutely nothing......the resistance reading of the sensor had to be on "K" ohms to come up with that reading......another test, is to set your multimeter for AC voltage and compare sides as you spin the wheel at the same speed.........

Diagnosing becomes a problem, when the light is intermittant, and you get data during a test drive......taking a "snap shot" with a scan tool during a test drive(include sharp turns), and then plotting the data is useful....

Unfortunately, only GM and good shops have these scanners....