GMC Sierra 3500 loss of power problems

Filed Sep 28, 2026 · Steering · TN

While operating my 2024 GMC Sierra EV Edition 1 at approximately 21,000 miles, a "Service Power Steering" warning appeared. Steering effort initially increased and then rapidly progressed to a near-complete loss of power steering assist. The steering wheel became extremely difficult to turn, making anything more than a gradual sweeping turn nearly impossible. I was able to safely exit the roadway into a parking lot. After shutting down and restarting the vehicle, steering assist returned to normal. No crash or injury occurred, but I believe this represents a significant safety risk because loss of steering assist at highway speed could result in loss of vehicle control.

Filed Sep 25, 2026 · Electrical, Engine · PA

Vehicle lost power, seemed to slip while pulling hills, Exhaust brake didn't seem to work. Dealer determined cause by DTC P209. Tested injector circuit, found loose terminal tension at injector number 6 connector. Replaced Cylinder # 6 injector connector. Did have multiple warning lights. Also submitting because Service Bulletin 23-NA+027 covered up to 2023. Believe it's an ongoing issue since vehicle is a 2024.

Filed Jul 30, 2026 · Transmission · WA

Since I purchased this truck in 2023 brand new as a 2024 the shifting has been very abrasive. It shifts far excessively harder than it should and I have brought this to the dealership’s attention many times. Now I am finding out that there is a massive recall on this vehicle’s transmission because of these issues that have been happening. The error codes are P0700 and P0747 The Engine and Transmission System is not performing as expected. An issue has been detected in the Transmission System that transfers power from the engine to the drive wheels. You may experience reduced power or shifting issues.If the vehicle is continually driven with the check engine light on, the emission controls might not work as well, the vehicle fuel economy might not be as good, and the engine might not run as smoothly. This could lead to future repairs.

Filed Jul 10, 2026 · Fuel system · FL

The vehicle experienced a catastrophic fuel system failure involving the high-pressure fuel pump and related fuel system components. While driving, the engine began stalling and lost power, making the vehicle unsafe to operate. The failed components were replaced during repairs; however, the repair records, photographs, and additional documentation are available for inspection upon request. The failure created a significant safety risk because the vehicle stalled unexpectedly while being driven, resulting in a sudden loss of power. This placed the occupants and surrounding motorists at risk by reducing the driver's ability to safely control the vehicle or move it out of traffic. The problem was confirmed by an independent repair facility, which documented extensive metallic contamination (metal shavings) throughout the fuel system. Photographs and videos taken during the inspections document metallic contamination within the fuel system. From our understanding, cp4 pump failure has been a common issue.

Filed May 15, 2026 · Engine, Transmission · TX · crash

While out of Town driving back home Wheel lock up on my 3500hd dually 2023 gmc .. vehicle had shudder effect and from 75 to 25 mph drasticly and engine reduced power light came on and wouldn’t come out of drive and then after stopping vehicle To cement parking safety block the vehicle had multiple codes for valve body and transmission failure relating to the na242454441 issue on previous year models and gmc is not working properly on a resolution but admitting that it is having the exact issue of previous models and with this issue I was promised for full replacement at no cost I am currently working with executive team to help fix the issue that the dealership in Levelland Texas is not honest about what codes are within parameters when infact have A dtc code reader and was able to get a photo and have history of code showing etc

Filed Apr 4, 2025 · Engine · MI

Driving my vehicle in the mountains pulling a 16000 lb 5th wheel trailer, the engine goes into Reduced Engine Power due to a Turbo Vane Position sensor / Turbo Over Boost or Under Boost fault. This has happened 4 times in the last 3 months and has nearly caused an accident following each occurrence. The vehicle is a 2016 GMC Sierra 3500HD with the 6.6L LML Duramax Diesel engine with 75000 miles. I believe the Reduced Engine Power protection is far to abrupt in the loss of Engine Power to safely move the vehicle out of the flow of traffic. During each occurrence I was in the left lane of a 2 lane expressway attempting to pass a much slower vehicle going up a 5-8% grade and was unable to complete my pass due to the loss in propulsion which nearly caused an accident.

Filed Jul 2, 2024 · Engine, Fuel system · 68,000 miles · NJ

The contact owns a 2022 GMC Sierra 3500. The contact stated that the check engine warning light was illuminated intermittently. The contact stated while driving approximately 50-70 MPH, the check engine warning light illuminated. Additionally, the contact noticed that the vehicle was experiencing reduced power and performance. The vehicle was taken to the dealer, where the NOx sensor was replaced and a manual DPF regeneration was performed. The vehicle was repaired and remained at the dealer. The contact related the failure to GM Campaign Number: N212351211. The manufacturer was notified of the failure and informed the contact that the vehicle was not covered. The manufacturer referred the contact to the federal safety agency Hotline for assistance. The failure mileage was approximately 68,000.

Filed Jul 17, 2023 · Engine, Fuel system · AZ

I own a 2016 GMC 3500 Diesel that had a serious mechanical breakdown while traveling on the freeway. The truck lost all motive power and needed to coast across 4 freeway lanes. Once towed to a local GMC Dealer, they diagnosed the problem as the Bosch CP4 fuel pump internally came apart while driving. I have to have this vehicle working so I got it repaired at a cost of $16,145. This is a known issue and losing all power while at highway speeds could have caused a serious incident. Please address this issue before someone dies.

Filed Nov 3, 2022 · Acceleration, Electrical · MA

Transmission control module failed. Reduced power to vehicle to first gear. Blinkers, speedometer door locks, and other Safety and driving devices did not work. Check engine turned on. Device is held at some gmc dealerships nationally however they will not sell the part to have the truck repaired.

Filed Oct 25, 2021 · Acceleration, Engine · CA

While towing our trailer, truck went into reduced power mode, regen message displayed; check engine light came on; loud bag occurred and hissing from under the hood. Truck slowed to 3 mph so we pulled to shoulder and turned the vehicle off. Truck had blown the hose off the the turbo. We reclamped and restarted. Displayed check engine light, reduced power & regen message to keep driving however truck wouldn’t go over a 3mph crawl. Truck lost all power, everything shut down and wouldn’t restart. No dash lights, no error, no crank, no power. We were dead on the highway in the truck lane while towing. This Truck goes into reduced power mode every time it tries to regen and we have had it to the dealer multiple times however, the problem continues to get worse. When it does regen, sometimes it takes hours. Dealer says needed a manual regen & that is their solution. Yet problem persists.