GMC Complaints

Display suddenly says "Steering assistance reduced, drive with care" Temp gauge goes to C and stays there. Radiator fans speed up and stay on after the car has been turned off. Dealer unable to find a diagnostic code for the problem.

Model: Sierra Denali Ultimate Engine: 6.2L V8 VIN: [XXX] Mileage at Most Recent Incident: Approximately 52,000 miles Safety Complaint Summary I am submitting this complaint to report a recurring loss-of-propulsion and engine power event involving my 2023 GMC Sierra Denali Ultimate equipped with the 6.2L V8 engine. This vehicle has experienced two separate incidents in which it suddenly lost power while being operated at highway speeds. During both events, the vehicle unexpectedly lost propulsion without warning and without any apparent driver input or mechanical indication beforehand. No warning lights, check-engine lights, reduced-engine-power messages, service transmission messages, or other warning indicators were displayed prior to the failure. The vehicle simply lost power while traveling in traffic. During both occurrences, I was forced to safely maneuver the vehicle to the shoulder of the roadway while rapidly losing speed among surrounding traffic. Once stopped, the vehicle would not resume normal operation until it was restarted. After restarting, the vehicle appeared to operate normally; however, the fact that this condition has now occurred twice raises significant concerns regarding the reliability and safety of the vehicle. Safety Risk This condition presents a significant and immediate safety risk because sudden loss of propulsion during highway operation can leave the driver unable to maintain speed, safely merge, maneuver, or avoid surrounding traffic. The unexpected reduction in speed creates the potential for rear-end collisions, loss of vehicle control, or other traffic accidents, particularly when operating on high-speed roadways. Because the vehicle provided no warning before losing power, there is little opportunity for a driver to take preventive action. Additional Information • Vehicle: 2023 GMC Sierra Denali Ultimate • Engine: 6.2L V8 • VIN: [XXX] • Approximate Mileage: 52,000 miles • Number of Incident INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 55

The lifters on my 2023 GMC Sierra failed and damaged my engine. The truck has approx 78,000 miles. I do have an extended warranty to 100,000 miles. I got the truck to my GMC Dealer who confirmed the problem was lifter failure. There might be camshaft damage but will have to tear the engine down. It seems like GMC is dragging there feet. It is known the lifters are a problem on this engine but GMC continues to sell them. There was no warning that the lifters would fail. The lifters could have failed while driving at high speeds and the driver could loss control.

The contact owns a 2023 GMC Terrain. The contact stated while driving at an undisclosed speed, the check engine warning light illuminated and the engine stalled. The contact attempted to drive the vehicle to the shoulder of the road, the engine seized. The contact stated while attempting to start the vehicle, the vehicle failed to start. The contact The vehicle was towed to an independent mechanic where it was diagnosed with a failed fuel pump. The contact was informed that the fuel pump needed to be replaced. The failure reoccurred. The vehicle was towed back to the independent mechanic where it was diagnosed with a failed fuel injector. The contact was informed that the fuel injector needed to be replaced. The vehicle was repaired. The failure reoccurred. The vehicle was taken back to the dealer where it was diagnosed with a failed Number 3 fuel injector. The contact was informed that the fuel injector needed to be replaced. The parts were ordered, and the vehicle was being repaired. The dealer was made aware of the failure. The manufacturer was not made aware of the failure. The failure mileage was approximately 45,000.

The contact owns a 2021 GMC Yukon. The vehicle was taken to the local dealer for a routine oil change. While driving, the oil low light illuminated. The vehicle was burning an excessive amount of oil. The local dealer was contacted again, but the vehicle was not diagnosed or repaired. The manufacturer was contacted, who referred to the local dealer. The failure mileage was approximately 149,000.

I again have noticed intermittent pulsing at low to medium speeds. At roughly 1k-2k rpm the engine at or about 10-20 mph is pulsating or hesitating with an obvious pulse which you can see on the tachometer as well (bouncing.) It seems like there is either a computer, fuel flow or electric issue. Also, at speeds up to the 40 mph range, this is happening as well. Yesterday while towing a small 7'x12' empty dual axle trailer I noticed it again, I occasionally use my trailer to haul small loads up to 4500lbs. This has happened before but this time I decided to notate this on your site, since reading about ongoing problems with the 2020 6.2L GMC Sierra 1500. I was aware of the other following years, 2021-2024? issues and that is why I purchased this 2020 year model. My truck will be available for inspection when the request is sent to me. Safety was not an issue, I ran my truck most of the day. I have not yet notified my Chevrolet dealer, Roger Dean, Cape Coral, FL. My truck has not yet been inspected for this issue. There were not any lights or warnings on display at time of incidents. Thank you, [XXX] [XXX] [XXX] INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

My engine with less than 5,000 miles died (engine was blown). While driving on highway engine died and wheels locked and almost caused a major accident. I had to get a tow and bill cost me 700.00. GMC is giving me the run around. Dealer stated that engine will need to be replaced. GMC is doing nothing to assist me, I have a car note with no truck GMC is the biggest scam.

This vehicle was bought brand new and has received proper maintenance from one dealership since purchasing. I had to replace the thermostat and radiator before owning the vehicle three years. Within two years of owning the vehicle, my battery went out, which I thought seemed a little early. Then shortly after, I noticed that my locks weren’t engaging when I took my car out of park. Then my car wouldn’t even lock. When I tried to do it on the door control, nothing happened, then when I used my key to do it, it caused the alarm to go off and I couldn’t get it to stop. This resolved after a day, and then it rained again, and it started again. This time, my car wouldn’t unlock and I was trapped in my vehicle and had to open the trunk to get out. This is a known issue according to GMC with no fix. I took it to the dealer, and the codes were saying BCM and told it was being replaced but instead was “serviced”. This issue has begun again, and now I’m being told the locks are the issue and not the BCM, and that may not be covered under warranty. Not being able to get out of your vehicle or not being able to lock your car is a safety issue for passengers leaving them vulnerable to theft, someone entering their car while they’re in it and hurting them. I have had so many issues out of this vehicle and I do not believe I should have to pay for a repair that is a safety issue KNOWN TO THE COMPANY. I feel unsafe driving this vehicle now and it doesn’t even have 60k on it. So I’ve estimated on the date of the first incident and the new one just Happened this week. The information about this issue can be obtained from my dealership and GMC as it is a known issue with no real fix.

I would like to document it took 7 trips to set the monitors after a failed smog check. That is 21 time going from 55 miles a hour to coasting to 20 miles a hour. on a freeway. Three times per trip at 2:00 - 3:00 in the morning. Also my Catalytic Converter went out at 26,000 miles. It should last 70,000 - 100,000 miles or 10 years. Catalytic Convertor was replaced by dealer. Will i have to replace it every 26,000 miles?

The contact owns a 2024 GMC Acadia. The contact stated that while back out of his driveway while in reverse(R), the contact hit another vehicle that was also parked in the driveway. The contact stated that back over prevention sensor failed to alert him that a vehicle was in his vicinity; also the vehicle did not apply the automatic braking system when closely approaching vehicle. The contact stated that the failure cause significant damage to both vehicles involved in the collision. The vehicle had yet to be diagnosed or repaired for the failure. The dealer nor the manufacturer had yet to be notified of the failure. The failure mileage was approximately 17,500.