2024 GMC Sierra 2500

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)

This vehicle exhibits the same failure described in NHTSA Recall N232426400 — spontaneous unlatching after rain due to water intrusion into the exterior tailgate release switch. I’m requesting a goodwill replacement under GM bulletin # N232426400 as the failure mechanism and part are identical. It has caused brake failure and nearly killed me because of battery drain while driving. All American Chevrolet of Midland Texas is refusing to solve the problem and says no recall is available.

Problem #1: Trailer brakes failed while pulling 40' fifth wheel trailer. Was driving at about 50MPH on a 55MPH road and was approaching a stop light. I went to apply my truck and trailer brakes simultaneously and quickly found out I had "lost" my trailer brake. This happened another two times within the next 10 mile trip to my house. I immediately disconnected my trailer and took my truck to the shop. The GMC Dealer fixed this issue, however, it is both scary and extremely dangerous to the public when something like this happens on a brand new truck. Problem #2: Right around 30,000 miles I was driving (unloaded) down the road at about 35MPH when I felt a hard clunk in the transmission followed by grinding noises - immediately a notice flashed on the dash stating the truck went into reduced acceleration and the check engine light came on. I brought my truck to a local GMC Dealer to be serviced on June 19th and they advised me it was the Allison transmission valve body. The part has been on back-order and my truck is still at the dealership sitting in the back lot with at least 4 other 2024 HD models. I called GM twice to inquire about Safety Recall N242454440 (covering 2020-2022 GM Vehicles) and recommend that it get extended beyond 2022 since the problem with the transmission valve body has not been resolved yet. I have not heard anything back from them since that call back in June.

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

Trailer brake controller will intermittently stop working. “Check trailer wiring” will show up randomly on the display and no trailer braking will be available. This has happened with 3 different trailers. The trailer wiring was gone over and the issue is with the truck. Trailer brakes work with other trucks and aftermarket trailer brake controllers. GMC and dealer were notified and no fix is available. Researching online there are several complaints about this. The trailer brake signal should default to being sent similar to all aftermarket trailer brake controllers. This would be much safer rather than not sending the brake signal at all. This HD truck is rated to tow trailers over 20,000lbs and without trailer brakes it causes an extremely dangerous situation. I was forced to pull over on the highway and purchase an aftermarket trailer brake controller to continue safe travel.

I purchased a 2024 GMC 2500 HD truck to pull a 2021 8,000 lb gvw camping trailer that is equipped with electric trailer brakes. My trailer has functioned perfectly related to the trailer brakes with my previous vehicle (2011 Toyota Tundra). With the GMC 2500, at approximately 3000 miles on the vehicle, a “trailer brake disconnected or disabled” and “check trailer wiring” warning began popping up on my information center of the truck. The trailer braking system would not function, though all other functions of the lighting and camera systems to the trailer worked indicating that the wiring and grounding were not an issue with the trailer. The brake system would intermittently return to normal. And then this warning and disconnected condition (i.e. no functioning trailer brakes) would return. This occurred rapidly, and very frequently. GMC has acknowledged a problem with some vehicles with this problem by publishing a TSB that purports to correct this issue (23-NA-149) that recommends replacement of the trailer brake control module (part no. 212327200000019B). I had this repair performed while on a trip in South Dakota away from my home state in Arkansas and the truck and trailer functioned as normal for approximately 3000 miles of towing. However, the issue has returned and my local GMC dealer repair shop (Little Rock, AR) places the blame on the trailer and not the truck. Towing with this 2024 GMC 2500 HD is very unsafe to the occupants and any others on the road due to loss of braking while towing a heavy load or navigating steep grades with a trailer equipped as described. This problem is now all over GMC/Chevy truck forums and is not just me or my combination. This issue is gonna get people killed.

The contact owns a 2024 GMC Sierra 2500. The contact stated while driving at an undisclosed speed, the sun struck the solar panel used to charge the battery, and the surge from the battery entered the pigtail going through the truck, and disconnected the brake module, causing it to become disengaged from the vehicle. The contact took the vehicle to the camper and vehicle dealer who both stated there was no issue for concern. The vehicle was not repaired. The manufacturer of the camper and the vehicle were made aware of the issue. The vehicle failure mileage was 8,000.