OK little confused here :), you said in first post that trac/brake is on when parking brake is released?
Trac light is an error warning and may well be a wheel sensor, but would have to be scanned with a chassis scanner. Most autoparts stores only scan "P" codes (Powertrain). ABS/Trac will set a "C" (chassis) code.
I would go ahead and raise car, put on stands, and inspect wheel sensor connections, you may find one that is loose or secondary locking tang is broken.
Sunday, August 30th, 2009 AT 7:19 AM