Good morning all-

I did a dyno about 6 months ago and immediately afterwards, my ABS INOP light came on and has been on since. I have since had the opti/waterpump replaced so the battery was disconnected which I would have thought would clear it.

Any thoughts on why and how to clear it?

This is a '97 LTI M6.

Thanks

 

The usual cause for this is the rear wheel speed sensor connection was disturbed or disconnected when they tied down the rear end on the dyno. You should get under and take a look.

 

A dealer can scan the electronic brake control module (EBCM) for codes, using a Tech 1 or 2, or a decent brake shop should be able to read it with a Snap-On or similar brake system scanner. A lot of possibilities, making guessing relatively non-productive. But, check the center high mounted brake light (CHMSL) for a burned out bulb.