The brake warning light stayed illuminated after a cold start. No issues prior. We did have two brand new tires installed on the rear a couple days earlier. Could this be related?
Brake Warning Light on 2008 Chevrolet Trailblazer
The "red" brake light or the "yellow" ABS light? If it's the red brake light it could be, the parking brake not completely released, Make sure the pedal comes all the way up. Worn brakes making the fluid in the master cylinder low, check brakes replace if necessary and /or top off fluid. Or maybe even a brake light bulb out. If it is the yellow ABS light one of the wheel sensors, wiring, or connections could have been disturbed when doing the tires.