does anyone know what would make the abs inop light go on? it doesnt come on all the time once in awhile, i did have 2 bigger tires on the back but i have the same size now on all 4. if i turn the car off and start it again the light goes off.also does anyone know how to fix it? thanks for your help

 

May be a bad sensor. Bad news is, the ABS sensor is integrated with the wheel hub.

I wound up replacing both my fronts (one bad bearing, one bad ABS sensor).

You might get a reading from a scanner to say which one.

 

Oh, and if it matters, the ABS system resets every time you turn on the car - so the light will go out at start-up, but come back on in a few dozen yards of driving. It may also cause a braking issue if you start off going downhill.

 

have your alternator checked. When i had my camaro, i installed a new head unit, my abs light came on guages acted all funny and finally it wouldnt start, so i brought it to be tested and sure enough it had gone south and wasnt charging the battery.

 

Iwould go withtraumadog's response. 9 times out of 10 it is a wheel speed sensor and or wheel bearing or the wiring to the sensor. I don't see how the alternator would cause this problem and no other problems??

 

Its free to test your alternator... whats the harm?

 

lol yeah I guess... but hes trying to fix his ABS light and the alternator has nothing to do with the abs light lol.

 

So explain why when my alternator started todie after i installed my headunit the ABS light came on and then when i got a new one it turned off?

 

Get your ABS system scanned to find out where in the flow-tree the problem lies. In my case, my '95 had a bad ABS Motor Pack an easy replacement to do yourself, but I paid to have the ABS diagnosed to zero in on the problem.

 

Well man maybe because your ABS control module wasn't getting enough voltage/amperageto it because your alternator wasn'tkeeping the battery chargedand itrecognized the problem and turned the light on.... But you also said your gaugeswere going crazy too, and there would also be other symptoms if the alternator was bad on his car like your car for instance no start, dead battery low voltage output ect..... Just trust me dude his problem is not the alternator. I am a GM mechanic and I have never seen an alternator turn the ABS light on and ONLY the ABS light.

The bestway to find the problem is to take it to a dealer or shop and have them hook it up to a tech 2and see what the problem is.