My brother and I just spent a lot of time troubleshooting a problem
with my 2001 Pontiac Grand Prix GTP. The ABS (anti-lock braking
system), the TCS Off (traction control system) and the service engine
soon warning lights were all illuminated on the dash.
I put together a troubleshooting web page with all of the possible
solutions and pictures to help illustrate the procedures.
Here's the link -
http://www.paulstravelpictures.com/GM-ABS-TCS-Off-Dash-Warning-Lights/index.html
I hope it helps someone save a bit of money and time.
Cheers,
Paul Michaels
Ft. Lauderdale, FL