2005 Chevy Tahoe, Brake Lights Come On w/Headlights

My brake lights come on and stay on when the headlights are on. Was told that the bcm controls this. Dealer wants more money than I have to replace. A new one will have to be programmed by the dealer so I'm told. Does anyone have any information that might be helpful. Thanks BigJon

Do you have separate plugs for the brake and tail lamps? What are the chances somebody got them mixed up?

I wish it was that simple. During the day when I press the brakes my park lights come on/off with brake lights.

Sounds like a bad ground on the brake lamp harness.

I'll try secondary ground for tail/brake lights

X2 with Mr. I.

x3 with Mr I. Usually however a bad ground results in a dimmer light - ie, it is the tail-light filament that glows, not the brake (assuming brake-tail common grounding). [Traditionally, your front parkers should also glow when the brake (light) is applied.] But if extra switching is used (relays or transistors etc), then full brightness is possible.