ABS light after car alignment

[gadan]

My Venture 2000 ABS light was coming on after checking a bad rotor in the front brakes. I was almost ready to replace the front rotos to correct the problem next weekend but I took my car to Pep Boys for a wheel alignment (because the car was puling to the right, a totally different problem) and now the light is always on since the moment you start the car, the system does not perform a check anymore. I asked the PepBoys technician and he said he did not touch anything. I'm sure he touched something when he did the alignment but I don't know what. Any ideas??

[AJT1961]

Does your van also have traction control? If not, check the wiring harness plugs in the rear of each of your front hub assemblies to (1) make sure they are both plugged in, and if they are (2) that they are not corroded. (If you have traction control, this is probably not the problem because it would cause the TCS light to come on as well). The Haynes manual probably has a troubleshooting procedure for this problem which I'll post if I can remember where I put it.

[gadan]

Originally Posted by AJT1961

Does your van also have traction control? If not, check the wiring harness plugs in the rear of each of your front hub assemblies to (1) make sure they are both plugged in, and if they are (2) that they are not corroded. (If you have traction control, this is probably not the problem because it would cause the TCS light to come on as well). The Haynes manual probably has a troubleshooting procedure for this problem which I'll post if I can remember where I put it.

Thanks very much for your help, I found that one of the wires was cut and that's why the light was on, I put toghether the cables temporarily and put electrical tape, I need to fix it in the future but for now works fine.

[phipps]

Originally Posted by AJT1961

The Haynes manual probably has a troubleshooting procedure for this problem which I'll post if I can remember where I put it.

We are having problems with the ABS light after a head on collision. The dealer says the front hub needs replaced.

Do you have the troubleshooting procedure still? I'd like to try that route before replacing the hub.

[AJT1961]

The Haynes Manual does not have a procedure because you need a special electronic tester to determine if the speed sensor in the hub is bad. I suppose it is possible, but I'd make the dealer show me exactly how he is diagnosing this problem. In other words, I'd have to see the mechanic unplug the hub, plug some kind of tester into the hub, and get a bad reading that is different from the opposite side hub. It could happen. The manual does say that before you bring it to a dealer, you should check the fuses, all of the plugs and wiring between the hubs, the electronic brake control module (EBCM) (under the dash) and the hydraulic modulator/motor pack (mounted on the master cylinder), as well as the brake light switch wiring. Hubs are routinely replaced if they have taken any kind of hit in a collision, but that is usually because of bearing damage (which you can hear while driving). I'd be really surprised if it was anything more than a wiring problem simply because of the laws of probability. Of course you'd probably never know because after they replace the hub and the problem is still there, they'll then find and fix the wiring problem. Dealer hubs are such a rip-off. Aftermarket hubs (e.g Autozone, etc) are a fraction of the price. Last one I bought cost me around $100 and took me about an hour to replace. Good luck and let us know how it turns out.

[phipps]

Thanks for the info. I haven't had a chance to actually take a look at the hub and wiring yet.