2017 GMC Sierra 3500 Problems

Trailer brake system connection warning Intermittent when towing it will say trailer not connected, while still having a secure 7 pin connection. This causes me to loose trailer brakes. My camper is nearly 14,000 lbs. Very dangerous situation. Happened since new. Was into / complained to GM service dept over 6 times.

SERVICE TRAILER BRAKING SYSTEM. Faulty control in the dash. Known issue per mechanic but no recall issued. Safety issue as trailer brake may not function properly when towing as a result

My truck is affected by GM’s engine block‑heater safety recall (NHTSA 21V‑496 / GM N212329840) addressing a risk of short circuit and potential engine‑compartment fire at the heater cord/terminal connection. GM’s interim action has been to remove/disable the block‑heater cord, which my dealer did, and then marked the recall “completed.” As a result, the NHTSA VIN tool shows 0 unrepaired recalls, even though no actual repair/restored functionality exists and GM continues to advise owners not to use the block heater until parts are available. Safety concern / impact: I live in a cold‑weather area and purchased this diesel expecting a functioning block heater for reliable cold starts. Disabling the heater has removed an intended cold‑weather safety/starting aid for multiple winters without a final fix. GM’s bulletin explicitly allowed dealers to disable the cord to close the recall, rather than provide a repair, leaving owners without the feature indefinitely. Suspiciously, I have also had to replace glow plugs on this truck sooner than traditional wear / failure rates would demand - including one glow plug that has been replaced twice in short span of time (should have lasted years). I continue to monitor GM’s recall portal; still no parts/remedy schedule. Please review whether GM’s chosen remedy—disabling a safety‑related feature and closing the recall—is adequate and within a reasonable time under the Safety Act. If not, I request NHTSA open a Recall Query into remedy adequacy and timeliness so owners receive a real repair (replacement heater/cord/connector) or appropriate alternative remedies.

Trailer brake system connection warning Intermittent when towing it will say trailer not connected, while still having a secure 7 pin connection. This causes me to loose trailer brakes. My camper is nearly 14,000 lbs. Very dangerous situation. Happened since new. Was into / complained to GM service dept over 6 times.

The contact owns a 2017 GMC Sierra 3500. The contact stated that while shifting from park(P) to drive(D), the engine revved, but the vehicle failed to move forward. There were no warning lights illuminated. The vehicle was towed to a certified mechanic, who determined that the vehicle needed to be diagnosed by a dealer. The mechanic was able to shift the transmission into manual drive mode, allowing the contact to drive the vehicle to the residence. The dealer was contacted and informed the contact that the VIN was not under recall. The vehicle was not repaired. The manufacturer was informed of the failure and referred the contact back to the dealer for assistance. The failure mileage was approximately 120,000.

The contact owns a 2017 GMC Sierra 3500. The contact stated while driving 30 MPH, there was smoke and a squealing sound coming from the passenger’s side rear wheel. The vehicle was taken to the residence and the contact observed fluid on the axle tube. The contact stated that the axle as taken apart and the wheel bearings were in pieces. The contact stated that the axle nut had unintendedly backed off. The vehicle was not diagnosed or repaired. The manufacturer was notified of the failure. The failure mileage was approximately 25,000.

My truck is affected by GM’s engine block‑heater safety recall (NHTSA 21V‑496 / GM N212329840) addressing a risk of short circuit and potential engine‑compartment fire at the heater cord/terminal connection. GM’s interim action has been to remove/disable the block‑heater cord, which my dealer did, and then marked the recall “completed.” As a result, the NHTSA VIN tool shows 0 unrepaired recalls, even though no actual repair/restored functionality exists and GM continues to advise owners not to use the block heater until parts are available. Safety concern / impact: I live in a cold‑weather area and purchased this diesel expecting a functioning block heater for reliable cold starts. Disabling the heater has removed an intended cold‑weather safety/starting aid for multiple winters without a final fix. GM’s bulletin explicitly allowed dealers to disable the cord to close the recall, rather than provide a repair, leaving owners without the feature indefinitely. Suspiciously, I have also had to replace glow plugs on this truck sooner than traditional wear / failure rates would demand - including one glow plug that has been replaced twice in short span of time (should have lasted years). I continue to monitor GM’s recall portal; still no parts/remedy schedule. Please review whether GM’s chosen remedy—disabling a safety‑related feature and closing the recall—is adequate and within a reasonable time under the Safety Act. If not, I request NHTSA open a Recall Query into remedy adequacy and timeliness so owners receive a real repair (replacement heater/cord/connector) or appropriate alternative remedies.

this vehicle is garage kept and meticulous maintained, has 136,000 miles, original owner, brought to dealer for an oil leak, they said exhaust are frozen and won't come out after heating etc. they have to replace exhaust manifolds! Bolts should not seize is the head of a garage kept vehicle that's heated! Being a mechanic many years ago I have never seen this happen! this is the first year for the new engine, On a internet search I found it's not uncommon, and the bill is going to cost me over $8000 !. Thank you, [XXX] INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

The contact owns a 2017 GMC Sierra 3500. The contact received notification of NHTSA Campaign Number: 21V496000 (Equipment) however, the part to do the recall repair was not yet available. The local dealer was contacted. The contact stated that the manufacturer had exceeded a reasonable amount of time for the recall repair. The manufacturer was made aware of the issue. The contact had not experienced a failure. Parts distribution disconnect.

WHILE DRIVING DOWN A MOUNTAIN ROAD WITH A 5TH WHEEL ATTACHED IT APPEARED THAT THE REAR BRAKES ON THE DRIVERS SIDE WERE SMOKING, I PULLED OVER TO ALLOW IT TO COOL. WE FOUND A GMC DEALERSHIP AND PROCEEDED THERE VERY SLOWLY STOPPING A NUMBER OF TIMES TO ALLOW THE BRAKES TO COOL DOWN. 2 MILES SHORT OF GMC, THERE WAS A LOUD POP AND A TIRE HAD BLOWN. WE PULLED OVER AND WHILE CALLING ROADSIDE ASSISTANCE NOTICED FIRE UNDER THE TRUCK. WE PUT IT OUT WITH A FIRE EXTINGUISHER BEFORE THE FIRE DEPARTMENT ARRIVED. WE WERE TOWED TO THE DEALERSHIP. THE BRAKE CALIPER CAME APART, THE REAR AXLE BROKE (POSSIBLY MELTED FROM HEAT AND FIRE?). GM INITIALLY STATED 4 DAYS TO REPAIR, NOW THEY THEY ARE SAYING 3 WEEKS AS THEY HAVE TO BUILD A NEW AXLE. IF WE HAD NOT HAD THE EXTINGUISHER THE TRUCK, RV AND MEADOW WOULD HAVE ALL GONE UP IN FLAMES AND WHO KNOWS THE DISASTER THAT COULD HAVE OCCURRED IF THIS HAPPENED ON THE MOUNTAIN ROAD. THIS VEHICLE ONLY HAS 17,000 MILES, 11 MONTHS OLD AND HAS HAD ALL ROUTINE MAINTENANCE PERFORMED AT GMC DEALERS. I HAVE MORE PICTURES BUT AM UNABLE TO UPLOAD THEM.

HEADLIGHTS SHAKE OR FLICKER AT THE SLIGHTEST BUMP OR CRACK IN ROAD. GM IS AWARE OF THE PROBLEM BUT HAS NO FIX NOR DO THEY PLAN TO.