I had the same problem. There is a small part in the rear axel that needs to be replaced/reset. It is a sensor. I was told I could do it myself, but didn't want to mess anything up so I took it to the dealer. $45 later, no brake light on.
Check your brake fluid reservoir. On some vehicles, if they leak fluid out, the parking brake light comes on as a warning.
you ask it to stop
I have a 1800 vectra and the break light comes on when traveling then goes off, is this the brake shoes or pads wearing out.
The red " BRAKE " light in your dash comes on if the parking brake / emergency brake is on and also if the BRAKE FLUID LEVEL in the brake master cylinder located in your engine compartment is LOW
that means your brake fluid is low
HOLD Foot Brake on and pull hand brake on and off 5 or 6 times there is also a cable adjuster under centre console remove box at rear to get to it you may need to service calipers if brake wont adjust hand brake works off front brakes not rear
It should go on when the brake is on and off when you release the brake.
Probably the level of brake fluid in the reservoir is low. This is telling you the brakes need service.
The brake light switch is broken or out of adjustment.
you need a new brake pressure differential switch
Light is usually comes on, when there is a problem with pressure in brake lines. Inspect the brake fluid level, and check for leaks.
You take your foot off the brake pedal.