The ABS light came on and when I stopped and turned the 2004 Silverado off a motor was still running underneath the truck (sounds like a whirring sound).. I disconnected the battery and then it stopped but I touch the cable to the battery post again and the whirring begins again. What is going on?
Make : Chevrolet
Model: Silverado 1/2 T Off Road
Explained in the question.
Is the noise just below the drivers seat area on the frame?
How many miles on the truck?
Yes, the noise is under the drivers seat area. The truck has 94,500 miles.
OK, the problem is the ABS module has a internal short that is keeping the abs motor running. This is a common concern on these trucks. Under the hood near the battery is a black box that has the fuses located inside. Remove the large fuse that is for the ABS. The cover of the fuse box has a label on it to show you what fuses are what. It should be a large (maxie) fuse and should be 50 or 60 amp. Remove the fuse and reconnect the battery. You can drive the truck like this, you will have normal braking but no ABS brakes.
To repair this issue, you need a new ABS module. The dealer will charge $600 to $800 for this repair. You can remove the module and send it out to have it repaired for about $150. Here is a website that can help you with the repair of the module. You remove it and send it to them and they will repair it. The site also gives directions on how to remove it. Let me know if you have any more questions on this issue.
15 YEARS AS GM TECH, TEAM LEADER/SHOP FOREMAN AT A GMC DEALERSHIP