2024 GMC Sierra 2500 Complaints

UNKNOWN OR OTHER — Filed 06/04/2026

The tailgate opens unexpectedly, it can be inspected but it is in for repairs on 6/15/26. There was luggage in the back and it could have fallen out on the freeway. The problem has not been repeated by the dealer, but it has occurred several times in the past. The vehicle had not been inspected by others. There was no warning that the tailgate opened. They start to occur randomly several months ago.

FORWARD COLLISION AVOIDANCE — Filed 06/08/2026

Unexpected braking at highway speeds. This has at least 50 times at highway speeds. The truck has experienced repeated false Forward Collision Alerts and un-commanded Automatic Emergency Braking events. Adaptive Cruise Control frequently detects roadside objects and vehicles in adjacent lanes, particularly on curves. The vehicle has never had windshield replacement, front-end damage, suspension modifications, or aftermarket accessories. This is creating a safety hazard because the truck brakes unexpectedly in traffic at any speed.

POWER TRAIN — Filed 06/04/2026

I was merging onto the highway in my 2024 GMC Sierra 2500HD AT4X equipped with the 6.6L Duramax engine at about 50mph when the gauge cluster emitted a “Reduced Acceleration Drive With Care” message followed by a check engine light. The check engine light presented indicated a “P0747” and “P0700” code. The vehicle was then stuck in 5th gear at highway speeds. Luckily there was no traffic present during this event due to the reduced acceleration of the vehicle and confusion caused to the operator. This could have been a dangerous situation due to the sudden change in handling of the vehicle. I have since then had the vehicle towed to the dealership in which it was purchased from for them to do their investigation to see how to fix the issue. This is a very well known issue with these GM heavy duty pickups. There is currently a recall on these trucks for this exact issue but my truck at this point in time is not included in said recall. I believe the recall is for 2020-2022 vehicles. Mine happens to be a 2024 which uses the same transmission as the older model vehicles in the recall. There are many other owners of these trucks like myself who have experienced this exact same issue. I’m sure this isn’t the first time this issue has been reported either. Something must be done about this.

ELECTRICAL SYSTEM,SERVICE BRAKES — Filed 03/13/2026

Intermittent trailer disconnect and loss of electric trailer brake output while towing Airstream. The truck is connected to the trailer through the seven Way plug. There are no modifications to the truck. This is a safety hazard as I pull a 9000+ lb trailer. Trailer connection drops momentarily and integrated trailer brake controller loses communication with trailer brakes. I went on a 5000 mile trip and my trailer brakes were connecting in disconnecting consistently. Every time there was a disconnection or connection the vehicle would “ding ding. This virtually happened consistently while we were on this long trip. During the trip, we tried to wedge the plug tight and zip tie the door shut, attempting to keep the plug tight. My truck is at the dealership, waiting on a “tool“. This is the second time it has been in the shop for this issue. I supplied a picture of the dash message after it got tired of connecting and disconnecting. I feel this is a serious safety issue. Thank you, [XXX] INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

ELECTRICAL SYSTEM — Filed 02/02/2026

IOK Radio Module failing. Would happen 10 times in less than 5 miles. Vehicle has been seen 3 times before diagnosing as IOK Radio Module failure. Inhibits hands free calling, total loss of all audio including safety chimes, dropped emergency call capability, multiple software updates have failed to resolve it. Vehicle is still under warranty. Serviced at Garrett Motors in Coolidge, AZ

ELECTRICAL SYSTEM,UNKNOWN OR OTHER — Filed 03/18/2026

IOK Radio Module failure. Inhibits hands free calling, total loss of all audio including safety chimes, dropped emergency call capability, multiple software updates have failed to resolve it. Vehicle is still under warranty.

AIR BAGS — Filed 04/26/2026

Driving back to camper in the late evening and was listening to music and gps was on the screen when I was going approximately 32mph when headliner airbags on both sides went off causing me to hit my brakes and veer into the ditch. I was able to maintain pretty good control but did hit either a rock or stick or something that punctured my wheel sidewall. Unsure if a tree limb then got caught and tore off my bedcover that then left a small dent on the c column on the passenger side. I was able to put my truck in 4wd to get back fully into the roadway and walk about to see potential damage. At that time I only saw my tire was loosing air and bedcover was off aside from the airbag deployment. I slowly made my way home to assess further during complete daylight. I was not injured other than a cut on the hand due to the bedcover and a headache from the deployment. No hard hit or collision and truck did not make contact with tree trunk or any front end damage that would ordinarily come from someone going into the ditch. Reached out to a shop to have them check it out and see if they can see any reason why those airbags would have deployed without force then causing an incident

ELECTRICAL SYSTEM,ENGINE,BACK OVER PREVENTION — Filed 10/01/2024

The contact owns a 2024 GMC Sierra 2500. The contact stated while reversing, the rear-view camera displayed a blank screen. The 4WD system engaged unintendedly, and the park assist sensor was inoperable while an unknown message was displayed. Additionally, the vehicle lost motive power while driving. The check engine warning light was illuminated. The vehicle was towed to the dealer, who replaced an unknown module and reset the computer, but the failure persisted. The contact stated that the vehicle was taken to the dealer five times, but the failure recurred after several unknown repairs. The vehicle was not repaired. The contact had requested for a buyback from the dealer, but no assistance was provided. The manufacturer was made aware of the failure. The failure mileage was approximately 8,000.

TRAILER HITCHES — Filed 03/07/2026

The contact owns a 2022 Safe Haven 12-foot Flatbed Trailer. The contact stated that while driving approximately 10 MPH and towing the unloaded trailer with a 2024 GMC Sierra 2500, while slowing down to make a right turn, the trailer detached from the tow hitch ball. The contact stated that there were no warning lights illuminated. The contact stated that the aluminum arms on the hitch adjoined to the frame of the trailer was loose. The contact stated that because of the design of the hitch, the receiver that rests on the trailer hitch was not flush, and there was room for the trailer receiver to move up and down, causing the bolts to loosen. The contact called the manufacturer and was informed that it was the normal of the bolts. The trailer was taken to an authorized dealer, and the contact was informed that the trailer was attached incorrectly. The vehicle was not diagnosed or repaired. The failure mileage was approximately 1,200. The VIN was not available.

ELECTRICAL SYSTEM,FUEL/PROPULSION SYSTEM — Filed 03/09/2026

The vehicle went into low power mode and said to pull over. As soon as that message appeared the next warning appeared and said to shift to neutral and pull over immediately and attempt to restart. The vehicle immediately shut off after second warning before having time to pull over from first message. I was able to pull most of the way off the road as the vehicle had shut off there was no power steering and had limited ability to steer the vehicle. This all happened without advance warning or any other warning that there was an issue while traveling at over 75mph. Vehicle would not restart and needed to be towed. Dealer stated it was a fule control module that was hard to get due to a recall. But that my vehicle was not part of that recall.

ENGINE — Filed 01/14/2026

Oil cooler blew and mixed oil in coolant reservoir. Possibly causes overheating and engine seizure. This has been confirmed with a certified GM service center. The service center inspected fixed it then within 5 miles had to be returned to the dealer because it happened again.

TIRES — Filed 03/03/2026

Traveling on I-10 doing approx 75 mph head a loud boom and saw sparks coming from the read drivers side of the truck. Truck was riding a bit low on that side. Pulled over and determined the tire had blown up. Currently doing the insurance claim and repair as there was substantial damage to the truck. No crash or involvement by other motorists. Did not hit anything.

EXTERIOR LIGHTING — Filed 02/25/2026

The contact owns a 2024 GMC Sierra 2500. The contact stated that the taillights, brake lights, and turn signals, all failed to illuminate. The vehicle was taken to the dealer, who confirmed that the rear lights had failed and needed to be replaced. The contact decided not to have the dealer repair the vehicle because the dealer stated that the repair was not covered by the vehicle manufacturer. The vehicle was taken to another dealer, Terry Labonte Chevrolet (1401 Bridford Pkwy, Greensboro, NC 27407), who confirmed the failure and determined that the lights needed to be replaced. The vehicle was not repaired due to parts not being in stock. The manufacturer was made aware of the issue and confirmed the repair was not covered under warranty or recall. The failure mileage was approximately 70,000.

STEERING — Filed 02/26/2026

Power steering randomly cuts out very random and intermittent. So far only done at low speeds but worried if turning in an intersection and i lose steering.

POWER TRAIN — Filed 02/05/2026

Truck had 3 momentary rear wheel lock ups on the highway from 41 - 52 mph.

FORWARD COLLISION AVOIDANCE — Filed 02/05/2026

On 3 separate instances the past few months the truck slammed on brakes for no apparent reason. And 2 separate times the past week or so the truck suddenly and uncontrollably accelerated — first at gas a station convenience store and almost ran over old lady, secondly while waiting line on arterial entrance ramp!

UNKNOWN OR OTHER,ENGINE — Filed 12/22/2025

I own a 2024 GMC Sierra Denali Ultimate 2500HD diesel that has been out of service for 52 days due to an oil cooler / service bulletin related failure. The vehicle is under warranty. The required replacement part is on national backorder and, as of today, has not shipped. The current estimated ship date is February 17. During this time, neither the dealership nor GMC has provided proactive communication. I have had to repeatedly contact them for updates. This extended inability to repair a critical component, combined with the lack of parts availability and communication, raises concerns about the reliability of this system and the manufacturer’s ability to support safe operation of the vehicle in a reasonable timeframe. The truck is my primary vehicle and is intended for towing and transportation. Being unable to repair it for nearly two months due to parts unavailability presents a significant safety and reliability concern.

ELECTRICAL SYSTEM — Filed 01/27/2026

Onstage control module fail and drains batteries leading to power failure.

POWER TRAIN — Filed 01/14/2026

The transmission made a loud noise, resulting in a sudden decrease in speed while driving in traffic. Felt similar to being rear ended in a collision. The lights came on in my dashboard including the check engine light. Tried driving the vehicle and it would shift erraticaly rendering un-driveable. Had to be towed to my GMC dealership for service. The initial diagnosis is an issue with the "valve body". a quick search on the internet presented several other users with this issue in this model truck with this transmission. The service department also seemed to be aware of the issue. If it is so widely known, why would there not be a recall placed on these vehicles? I'm glad I had already dropped my son off at school and that I was not on a Main Street where I could safely pull over and wait for the AAA driver.

ELECTRICAL SYSTEM — Filed 01/04/2026

About 2-3 months ago I had a battery swell up and start smoking and making an awful smell in my truck. I took it to dealership and was informed that I needed a new battery and it was not covered under bumper to bumper warranty or my extended warranty which I thought was ludicrous. The truck is 18 months old. It does have 50,000 miles but I have yet to see one that isn’t at least prorated for five years. So fast forward to today and the other battery starts doing the same thing except this time my lights are going crazy. Brights on and off and on and off. I get back to my camp and the battery and wiring is smoking like crazy. I towed it to the shop. It’s been in there two weeks and the only thing they tell me now is that I need 2 new batteries and that’s all they can do until I agree to pay for the other one that isn’t under warranty (because I already paid 300 to change 1st one it’s under warranty for 5 years). So I told them to do it. It’s been there two weeks and not a damn thing has been done. Not even installed a new battery. I know because I went yesterday and they couldn’t open my tailgate to get my tools out. Probably the last GMC I purchase.

ENGINE — Filed 12/23/2025

Complete engine failure with no warning on major road in heavy traffic. Very dangerous situation to pull off safely. Vehicle was towed to dealer and confirmed engine is seized. Unknown cause at this time. Transmission has had valve body replaced prior to engine failure. Transmission still has shudder after valve body replacement and prior to engine failure.

ENGINE — Filed 12/28/2025

Constantly having to clean the map Senor to be able to drive pickup without service emissions alerting me to clean the map Senor or my truck goes in limp mode. This can’t be normal to have to clean this so much. My truck is fairly new and should not be having these issues. Put a scanner on my GMC and the code says P122D. I got on YouTube and I found MANY people complaining about my exact problem for quite some time!

POWER TRAIN — Filed 10/18/2025

Vehicle shudders while accelerating and a constant speed from 1000-3000 rpm. Vehicle will shudder/shake for hundreds of miles at highway speed. Vehicle shakes violently going up steep grade. Vehicle shake is so consistently random it makes passengers ill. Warranty claim denied by GM after issue was recognized by technician.

SERVICE BRAKES — Filed 12/01/2025

Premature brake pad wear on all Brakes. All break pads worn down and had to be replaced at or before 25,000 miles. No trailer pulling and only light driving. Dealer stated rotors needed to be turned as well due to extremely low brake life.

ELECTRICAL SYSTEM,SERVICE BRAKES,ENGINE — Filed 02/18/2025

024 GMC Sierra 2500 Denali Ultimate, which has suffered: •Five catastrophic engine failures at highway speeds. •Total brake failure, leaving the truck unable to stop. •Severe electrical malfunctions, including flickering headlights at night. •Retaliatory actions from General Motors after I refused to waive my legal rights. I have documented proof, including GM’s own service records, emails, and a 7-minute recorded statement from GM’s highest-level technician, confirming that GM installed the wrong computer module (1500 series instead of the required 2500 series) in my truck. Additionally, I have evidence that GM executives instructed technicians to conduct diagnostics, take apart the engine, and reassemble it—but NOT repair the defect—after I refused to sign an affidavit waiving my rights. Due to these failures, I suffered a dislocated shoulder in one of the incidents, and my [XXX] daughter remains traumatized to this day. Given the immediate danger this defect poses to other GMC Sierra 2500 owners, I respectfully request that NHTSA open an investigation and consider issuing a recall before a tragedy occurs. 1. Engine Failures Since 3,000 Miles – GM’s Own Work Orders Confirm Issue Since purchasing my 2024 GMC Sierra 2500 Denali Ultimate, I have experienced five catastrophic engine failures, all occurring while traveling at highway speeds (70 mph): •The truck suddenly lost power, dropping from 70 mph to 5-10 mph within seconds. •This created an immediate risk of being rear-ended or losing control on the highway. •GM’s own service records confirm that my engine issues began at just 3,000 miles. •GM dealerships misdiagnosed the issue FOUR TIMES, returning my truck to me in an unsafe condition. •The real cause was only identified after the FIFTH failure, when a GM-certified head technician finally determined that GM had installed the wrong computer module (1500 series instead of 2500 series). This means that for months, GM knew my vehicle w INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)