GMC Sierra 3500 check engine light comes on

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 Sep 5, 2025 · Transmission · FL

While driving on the interstate we were exiting to pull into a rest area while slowing down the rear wheels momentarily locked up and the truck downshifted hard and abruptly with that happening the check engine light came on along with a decreased power message. We pulled into a parking spot during so we tried to shift into reverse and it didn’t want to shift into reverse, we tried this for a while. We finally got it into reverse and we were able to back out of the parking spot. When we tried shifting to drive we encountered the same issue. The vehicle did not want to go into drive. Once finally into drive it did not want to shift into any higher gears. It was essentially stuck in one of the gears. We made it to a GMC dealer on the next exit -we drove on the side of the interstate to get there- when we arrived we had them run the codes and they told us it was a transmission control valve which GMC has had a major recall on. While we had this “fixed” at a different dealership previously in march of 2025 it only entailed “updating the software” involving the transmission control valve. We had to leave the truck at the GMC dealer that we were able to ‘limp’ to in Crestview FL. We’ve been told our truck now needs an entirely new transmission that is going to cost $7,000. We had a similar issue right after the “software update for the transmission control valve” on march 20, 2025. The software was updated roughly a week before that incident which seemed to have cleared itself because it was momentarily and never happened again until now. Our safety was at risk because we had to drive on the side of the interstate to get to a shop because we were out of town and a tow truck was going to cost between 600-1000 dollars to get home.

Filed Jun 1, 2025 · Transmission · WA

Formal Complaint Against General Motors and Dealership – Ongoing Warranty Issue and Vehicle Inoperability To Whom It May Concern, I am writing to formally escalate a serious and unresolved issue regarding my vehicle, and the lack of meaningful action taken by both General Motors (GM) and an authorized dealership. My case is not isolated, it mirrors the experience of thousands of other GM customers facing the same known mechanical defect, as widely documented in online forums and communities. On [XXX], I purchased a used 2023 GMC Sierra 3500 Denali with approximately 25,000 miles from a dealership. The vehicle included the original factory warranty, and I also purchased an extended warranty for additional coverage. On [XXX], at approximately 26,000 miles, the truck unexpectedly entered limp mode and the check engine light came on while I was driving with my children. Please note—this truck is equipped with the Allison Transmission, which is marketed as one of the most reliable transmissions available. I immediately took the vehicle to Blade Chevrolet in Mount Vernon WA, the nearest dealership, where it remained for nearly a week before a diagnostic was completed. I was informed by the lead mechanic, Jason Visten, that the issue was a failed valve body solenoid #1—a component he clearly identified as a known and widespread issue within GM’s system. Mr. Visten further stated that GM has not been responsive to the dealership's requests for this part, which is currently on national backorder with no estimated timeline for availability. I was even told this specific part is being built for new vehicle production and are being prioritized over parts needed for warranty repairs, leaving my truck unusable and indefinitely sidelined for up to a year per Blade Chevrolet. I contacted GM Customer Service directly and received the same generic response. Also worth mentioning I almost got rear ended cause of limp mode activation and transmission locked up. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA

Filed May 21, 2025 · Brakes, Engine · LA

Engine started skipping, then service parking brake light came on, then service engine light came on and speed dropped to 44 mph.

Filed May 16, 2025 · Transmission · CO

Transmission issues 5/5/2025, bearly 15,000 miles on it, was excelerating from a stop heading down hill when rear tires locked up, engine downshifted, engine light and limp mode flashed across my screen. threw it into nutral and coasted to next signal and pulled into gas station back parking lot. No codes pulled. called dealer to share and they knew exactly what was wrong with transmition value body problem. but is my transmission ok? Towed to dealer, no fix in sight. 7th vehicle at dealer with same problem. Others been there for months waiting on same part. Thank God I wasn't towing anything, but now I have to pay for rental and they say they are waiting on parts??

Filed May 13, 2025 · Transmission · 36,000 miles · OK

The contact owns a 2024 GMC Sierra 3500. The contact stated that while driving on the highway at 50 MPH, the vehicle lost automotive power and failed to exceed 50 MPH. The contact stated that the check engine warning light was illuminated. The vehicle was taken to a local dealer where the vehicle was diagnosed, and the contact was informed that the transmission valve body was faulty and needed to be replaced. The vehicle was not repaired. The manufacturer was not notified of the failure. The approximate failure mileage was 36,000.

Filed May 2, 2025 · Electrical, Engine · CA

The contact owns a 2024 GMC Sierra 3500. The contact stated that the exterior lights of the vehicle were flashing erratically, and the tailgate was opening unintendedly. The contact stated that while driving at various speeds, the vehicle experienced erratic transmission shifts, and the vehicle was jerking and made an abnormal clunking sound. The check engine warning light was illuminated. The contact pulled over to a truck stop and parked the vehicle. The contact stated that the battery became fully drained while parked with the windows rolled down in snowy weather. The contact stated that after waiting 6 hours for AAA to arrive, the vehicle jump-started. The contact stated that the battery had drained on several occasions. The vehicle was taken to the dealer, where it was diagnosed that the two batteries needed to be replaced. The vehicle was repaired; however, the failure persisted, and the vehicle overheated while driving. The contact stated that GMC OnStar was contacted and informed the contact that diagnostic trouble codes related to the transmissions were retrieved. The vehicle was taken to another dealer Weston Buick GMC (22555 SE Stark St, Gresham, OR 97030) to be diagnosed. The vehicle was being diagnosed. The vehicle was not repaired and remained out of the contact's State of residence. The contact related the failure to an unknown recall; however, the VIN was not included. The manufacturer was notified of the failure and covered vehicle rental expenses that allowed the contact to return to their residence. The contact stated that the vehicle was used for load transportation, and the failure had caused both the contact and her husband to be stranded while delivering loads, which caused lodging expenses and loss of wages. The failure mileage was unknown.

Filed Apr 30, 2025 · Transmission · 63,000 miles · VA

The contact owns a 2024 GMC Sierra 3500. The contact stated that while driving at 30 MPH, there was a loud pop and the vehicle jolted, after which the vehicle started to lose motive power. The contact was able to pull over to the shoulder of the roadway, where the failure persisted. The check engine warning light was illuminated. The vehicle was towed to the dealer, who diagnosed a failure with the transmission valve body. The vehicle was not repaired due to a lack of parts availability. The manufacturer was notified of the failure, a case was opened, and the contact was referred to the federal safety agency Hotline for assistance. The failure mileage was 63,000.

Filed Apr 25, 2025 · Transmission · 33,800 miles · FL

The contact owns a 2023 GMC Sierra 3500. The contact stated that while hauling a trailer and driving approximately 40 MPH, the contact attempted to merge into traffic and the message "Restricted Power Mode" was displayed. During the failure the transmission failed to properly shift into a higher gear, and the vehicle failed to exceed 67 MPH. The contact stated that later while driving at an undisclosed speed, the check engine warning light illuminated. The vehicle was towed to the local dealer who diagnosed that the transmission valve body was faulty and needed to be replaced. The vehicle was not yet repaired. The manufacturer was notified of the failure. The failure mileage was 33,800.

Filed Oct 30, 2024 · Brakes, Electrical · TX

Various warning lights are coming on sincve I purchased this vehicle, such as ABS, engine power reduced, oil changing service, service engine light, service trailer brake system, wheel tracking, service ESC, passing gear cuts out. My vehicle has been in the shop many times and is in the shop now. I have a deep concerned for the safety performance of this vehicle for myself and my family.