anti lock warning light stays on

The anti-lock warning light stays on when I drive my car.
The brakes still work perfect. I want to check my ABS sensor first, maybe it's just dirty. Is this easy? And where is the sensor located? And what other options do I have or what else can I check?

The sensors are on the front spindles behind the disks/hubs, and on the pinion shaft in the rear. The can get dirty, and the tone rings can also get dirty. The tone ring is on the inside of the front hub. I would also check the connectors on the wheelhouses. The connectors are usually yellow, and are prone to disintegrating when touched. You can get pigtails for the connectors, and solder them in.

If you are going to replace the sensors, you will probably have to drill the old ones out. They become one with the spindle, and self destruct when removal is attempted. When putting the new ones in, you might consider coating them with anti-seize before inserting them. There is one screw that holds them in place besides the corrosion that impedes removal. The sensor in the rear is not a high failure rate item, and I would not worry about it, except for the connector. The connector is the same type as the front ones on the wheelhouses. It is not exposed to heat like the front units, and does not deteriorate as quickly, but check it anyway.

The brakes will still work normally when the ABS light is on, but the ABS system is off line.

Thanks for your information. You were right about the front sensors, the were really hard to get out. The bolt went off very easy but the sensor it self was a pain in the ass.
I'm going to check the rear sensor later because I think that the problem of the 'anti-lock warning light' thats on, while driving, is caused by dirty front sensors. So, I'm going to order new cables with sensors. Does anyone know a cheap place, because $80 seems a lot for a little cable.

E-Bay generally has the lowest price, Around $60.00 a side. The right and left sensors are different, 88963120 and 88963121.

The ABS system will tell you what failure set the light to come on. You have to find someone with a Tech 1 tool.

Thanks Rob, you are right, left and right are different. How does a tech 1 tool work? I saw one for $22 on Ebay.

How does a tech 1 tool work?

It is basically a hand held device that interfaces with your on-board electronics and gives readouts and readings of what is going on in their innards. You can also do some manipulating of outputs with it. The key is that the Tech 1 requires different cartridges to talk to different systems and vintages of vehicles. There are (at least) different cartridges for the PCM, the BCM, and the Antilock system which is Bosch based and uses different communication protocol. Make sure the one offered has the correct plug-in cartridges for your application.

Also very unlikely you found one for $22. You might have found a single cartridge, but the whole system is very expensive. Here's one, for example:

http://www.ebay.com/itm/GM-Tech-1-scanner-/172823027010?hash=item283d0e1d42:g:svoAAOSwlY1ZKtKX

I do not think the sensors are cheap anywhere. Rock Auto is probably the cheapest, because shipping is cheap for small items.

Chevy freak '91 wrote:

The anti-lock warning light stays on when I drive my car.
The brakes still work perfect. I want to check my ABS sensor first, maybe it's just dirty. Is this easy? And where is the sensor located? And what other options do I have or what else can I check?

You could do the BD1 mod to fix the annoying constant light on in the dash.

Well, I've replaced both the ABS sensors and my 'anti-lock' lights doesn't stay on anymore. So the sensors were the cause of my problem. Thanks for all the help guys.

Now, I have another problem, sometimes my 'check engine soon' dashlight is on. But some periods of time it isn't on. It's hard to say when it is on or off.

Use a jumper on the ALDL connector from pins " A" and "B". Turn the key to ignition, but do not start the engine. The SES light will flash ("1" "2") 12 twice, then it will flash the two digit codes three (maybe only twice) times each, then it will flash 12 again.

It could be anything from the O2 sensor to the EGR valve. When you get the codes, post them, and you will get possible issues with the system. It is always cheaper to troubleshoot the system before you start throwing parts at it.