This bulletin applies to a host of 2010-2014 GM vehicles (Chevy, Buick, Cadillac, GMC). A customer may comment that the vehicle brake lights remain on with the vehicle off and the battery going dead while parked.
A possible cause may be the installation of an aftermarket mechanical theft deterrent device that interacts with the brake pedal. Theft deterrent devices that mechanically attach to the brake pedal may move the pedal from its released position, causing the brake lights to stay on.
Prior to replacing any parts, confirm with the customer whether they use any type of aftermarket theft deterrent system.