The Office Of Defects Investigation (ODI) opened this investigation on model year (MY) 2002-04 Chevrolet Trailblazer vehicles.GM reports that other vehicles sharing this platform and brake lamp design are the MY 2002-2004 Chevrolet Trailblazer ext; GMC Envoy, XL, xuv; Oldsmobile Bravada and 2004 Buick rainier.complaints allege that the rear brake lamp does not operate when the brake pedal is depressed.there is no indication to the driver from inside the vehicle that one or more brake lamps bulbs are not functioning.GM found that heat from the bulb could deform the lamp socket, produce electrical arcing and an inoperative bulb.to correct the condition, GM changed the bulb to a bulb that transmits less heat to the socket and changed the socket to a thermoplastic polymer to improve thermal stability.these changes were implemented into production vehicles on October 1, 2003.GM implemented a special policy by notifying consumers that if they should experience a brake lamp failure to go to their GM dealership to have the circuit board containing the brake lamp replaced along with new bulbs.this policy is good for the first 6 years or 72,000 miles of the life of the vehicle.ODI will upgrade this investigation to ea 04-021 and include the above mentioned vehicles.
