Century 2002 Anti-Lock/Trac off/SES

[biged77]

The Anti-Lock, Trac off and Service Engine Soon (left one) come on after I have started the car and the car has gone from a few feet to a mile or two (sometimes more). The cruise control works fine and no brake lights are out. The computer says it is a left front ABS sensor. It costs $400-$500 to replace this sensor (requires wheel hub replacement). What are the chances that this won't fix the problem? Before the 3 warning lights come on the headlights dim intermittently and there is an intermittent low pitched noise but after the warning lights come on these no longer occur. I am afraid that the problem may be in the ABS control system instead of the sensor. Should I seek out a repair shop (or the dealer?) that can do diagnostics on the ABS system to make sure the wheel sensor is the problem or should I just go ahead and get the sensor replaced and hope for the best? Does a bad or intermittent wheel sensor cause symptoms like I described? Anyone who has had a similar problem and your experience in getting it fixed (or not fixed) would be appreciated.

[sierrap615]

check the sensor for rust or metal shavings(it has a magnet inside). check the toner ring for damaged teeth. if both check out fine ether replace the wheel sensor or send it off for a full diagnositic(dealership). without the EXACT code thats about all i can say.

[biged77]

Originally Posted by sierrap615

check the sensor for rust or metal shavings(it has a magnet inside). check the toner ring for damaged teeth. if both check out fine ether replace the wheel sensor or send it off for a full diagnositic(dealership). without the EXACT code thats about all i can say.

Thanks for the suggestion.
I tried to check the sensor but can't see it because it is inaccessible (down inside the wheel hub). If the toner ring is at the wheel this is inaccessible too. I finally checked on replacing the wheel hub. I called the dealer and asked if he had any anti-lock brake test equipment or would just rely on the diagnstic code (which says the left front wheel sensor is bad). He said he would replace the wheel hub, cost about $650-700 then go from there if this didn't do it. I had a local repair shop replace the wheel hub for $300. The problem is still there. So the way I see it I saved $350-400, right?

Seriously, what should I do next? I have seen some anti-lock test equipment on the Web but apparently no shops around here have any.

Is there a GM website that could give me some advice on this problem? It is a safety issue and it would seem that more information would be available. I can't see taking it to the dealer and waiting on the bill which might be a good portion of the car's value after they are finished.

[sierrap615]

Originally Posted by biged77

He said he would replace the wheel hub, cost about $650-700 then go from there if this didn't do it.

i would never go to that dealership again, throwing parts at a problem is not the way to fix something, expecially when its electrical and $700 of a customers money. if i was doing the job the test equitment would be nothing more then a scantool and a DMM, or an osilioscope at most. if you have said tools i can guide you threw it, or take it to a different dealership.

[biged77]

I have a DMM and will buy a scantool. What next? Any help is appreciated.

[biged77]

Latest on anti-lock saga: I had the left wheel hub replaced. Cost $300.00 The symptoms after replacement were the same, still have the same lights lit. I then took it to another shop for more troubleshooting. The scantool still says the left wheel sensor code comes in intermittently, which is consistent with the anti-lock light coming in after driving a few seconds/minutes. They could find nothing else wrong with their equipment. I then checked with the Buick dealer on the cost of anti-lock parts. There are two parts, a control module and a valve module. They are each about $650-700. The next step is to take it to the Buick dealer to see if they can find out which one is bad (if either), and then get a used part and replace it. For some reason I don't have much confidence that this will fix the problem either. For the time being I have disconnected the anti-lock module. This makes the break light come on but that's better than listening to the strange noises the anti-lock system makes before the various lights come on.

[stevens2789]

Did you ever get your problem fixed? I have a 98 Intrique that just started the same combination of lights.

[UncleBob]

very old post....but I'll put it here anyway...

as untiutive as it is, its probably the ignition switch. Had a very simular problem on a car I was working on, and it had a large voltage drop through one of the contacts in the switch. Car also had a stalling problem...but thats the only difference from your discription.

Replace the switch and all was good.