GMC Sierra 2500 brake failure problems

Filed Jun 18, 2026 · Brakes, Steering · TN

Normal driving 40mph brake failure and power steering loss. Towed vehicle to dealership

Filed Oct 24, 2025 · Brakes, Electrical · TX

This vehicle exhibits the same failure described in the federal safety agency 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.

Filed Sep 1, 2025 · Brakes, Transmission · TX

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.

Filed May 30, 2025 · Brakes, Steering · NY

Experienced loss of power steering, loss of brakes

Filed Feb 18, 2025 · Brakes, Electrical · TX · crash · 3 injuries

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 the federal safety agency 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

Filed Jan 12, 2025 · Electrical · NH

Trailering a trailer with electric brakes. The vehicle intermittently reports connection issues where the brakes are temporarily disabled however the trailer lights are not effected. This leads to a period of time where there are no brakes on the trailer. Pretty confident we have eliminated the trailer as causing the issue.

Filed Jun 13, 2024 · Brakes · AR

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.

Filed May 30, 2024 · Electrical · NC

Brake control module disconnects trailer brakes while towing. Apparently a known issue with trailers equipped with solar battery chargers which have higher charge than vehicle battery. It feeds back into the trailer brake power module causing it to shut down. The vehicle has an integrated trailer brake controller as it is specifically designed with primary function as a tow vehicle. Shutting down the integrated trailer brake controller results in loss of trailer brakes. Not having trailer brakes is critically dangerous. GM has issued a TSB #23-NA-149 specifically addressing this known defect. Unfortunately, GM refuses to authorize its service technicians to replace the defective brake controller unless they experience the defect personally - the policy is to disbelieve the customer with the defective vehicle. Effectively, this requires providing the trailer to the service tech to drive around until the brakes fail, thus creating another dangerous situation for a tech who may or may not have experience driving vehicles over 50’ in length. Thus, it would appear the best remedy is to enforce a recall to replace the defective brake controller before someone is harm by loss of brakes, since GM requires its techs to encounter a loss of brakes before authorization of replacement of the known defective unit. This happened over 25 times during a trip last week. This fact situation reveals why your Administration actually exists - to protect the public from harm.

Filed Mar 20, 2024 · LA

GMC has a problem with the electronic brake controller on their 2024 Sierra 2500HD and 3500Hd trucks. All trailers are required to have trailer brakes. In addition the trailer must be equipped with an auxillary battery to activate the emergency breakaway brakes. If the voltage on this battery is higher than the towing vehicle battery, the vehicle controller can display a trailer wiring fault display. When this happens there are no brakes on the trailer. This fault happens intermittantly and can last between 10 seconds to 30 seconds. We constantly have this problem with our vehicle. On two occasions we were in an emergency situation towing a12,500 lb load and had no brakes. This is A SEVERE SAFETY CONCERN. The GMC dealer stated that the problem is because our trailer uses a regular car battery to work the hydraulics and the brakes. They stated that the controller pings the trailer to see is anything is connected and that the car battery can interfear with this signal. When this signal does not return the controller senses that no trailer is connected and disables the trailer brakes. The trailer that we have is new and it is wired according to industry standards. Thre are thousands of trailers on the road that have this configuratiion. We have inspected the trailer and cannot find wiring problems. We have towed the same tyrailer with two different trucks and do not have this problem. A quick search on the internet will reveal that many other people are experiencing the same problem.

Filed Nov 7, 2023 · Electrical · 55,756 miles · KY

The contact owns a 2017 GMC Sierra 2500. The contact stated that while his wife was driving at an undisclosed speed, the vehicle experienced a loss of power steering assist, and the brakes failed to stop the vehicle immediately. No warning light was illuminated. The vehicle coasted to the side of the road. When the contact arrived on the scene, he noticed that the generator pulley had detached. The contact then purchased a new generator, which he replaced himself. The vehicle was repaired. The manufacturer was not made aware of the failure. The failure mileage was 55,756.