My 2006 Silverado 2500HD Duramax Diesel in now stuck in Park. It started with my brake lights not working and no power to rear brake lights. Replaced the Brake Pedal Switch per suggestions on the net and still no brake lights but now I can't shift out of Park.
When I disconnect the wiring harness to the switch then I can shift normally. I replaced the switch 2 more times with the same results.

Any ideas are welcome. Thanks.

 

can you hear the brake shift interlock clicking when you apply the brake pedal? This device prevents shifting out of park unless the brake pedal is pressed.

 

No, I can't hear any clicking, but then again my hearing isn't what it used to be. Where is the brake shift interlock located? Thanks for your quick reply.

 

You can usually hear them if you listen, they are in the column.

But it sounds like something related to your brake switch which your lights and brake lock are tied to.

Are you sure you're getting a good part? Might need to check the wiring and see if something is cut or skinned.