2023 GMC Sierra 2500 transmission problems

Filed Nov 3, 2026 · Electrical, Steering · WI

When vehicle is shifted into Park you are not able to remove the key. I have taken the vehicle to 5 different dealers, and no one can fix the problem. Many forums show the exact same problem - something in the steering column is defective. Began happening in 2023 with only 12,000 miles on the vehicle.

Filed Jul 7, 2026 · Brakes, Electrical · AK

On XXX, I was towing my camper to Copper Center, Alaska from Palmer, Alaska when my truck experienced a full transmission shut down which put the truck into "Reduced Power Mode". We descending down the road right next to Victory Bible Camp (64741 Victory Rd, Sutton-Alpine, Ak 99674) when the exhaust break turned off and the truck decreased power and the Check Engine Light illuminated. The Diagnostic that was produced by OnStar revealed 3 different codes. ( P0700 TCM, P0747 Pressure Control Solenoid A is stuck in the "ON" position, C116b faulty brake pad wear sensor.) I called GMC of Palmer and GMC OnStar advisor, both informed me that the truck needed to be towed. My safety concerns is this.... I had minimum cell phone signal and not a gas station or service station within MILES. I was on the side of the Alaska Highway 1 which is a major thoroughfare for traffic going to and from [XXX]. Thankfully there were a few kind folks that pulled over to offer assistance. My truck is a 2023 GMC Sierra 2500hd with only 26,262 Miles on it. I purchased this vehicle XXX. (It Still has the Temporary Tags on it.) If had been in a different part of Alaska when this transmission failed to function properly then we could be talking about a life or death situation. Especially, if my child was with me. I was hauling my camper that weighed ATMOST, 7,000 pounds. This is less than 40% of the trucks ability. I feel that this could put someone into a dire situation had they not had the experience with emergency situations like I have had. (Prior Military Service). I have also filed a complaint with GMC Motors. Case# XXX. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

Filed Jan 24, 2026 · Transmission · PA

Driving at approximately 30-35MPH merging in traffic, the transmission shuttered and went into reduced power mode. ECM reported a 747 code and valve body failure.

Filed Jan 12, 2026 · Transmission · MO

Summary of Issue On [XXX], my family and I departed Kansas City, Missouri, for a camping trip to Great Smoky Mountains National Park (Cades Cove), Tennessee, approximately 800 miles away. We were towing a 2020 Forest River Salem FSX/RTX travel trailer, estimated at approximately 6,000 pounds loaded, using a Reese weight distribution hitch with integrated sway control. This load was well below the rated towing capacity of the vehicle. On [XXX], while driving without the trailer attached, the vehicle displayed multiple warnings including “Reduced Engine Power” and a transmission system alert. I immediately pulled over, shut the vehicle off, and restarted it. The warnings persisted. I cautiously drove approximately five miles to Twin City GMC, where the vehicle was diagnosed with a failed transmission valve body. Dealer and Manufacturer Response The service manager at Twin City GMC informed me that the required valve body was on national backorder, with multiple vehicles ahead of mine, and that wait times had reached up to three months. To confirm, I contacted Molle Chevrolet (Blue Springs, MO) and Randy Curnow GMC (Kansas City, KS). Both dealerships independently confirmed that this was a known and recurring issue, and that extended backorders for the valve body were common. I was informed that GMC could provide a daily rental allowance, but the rental vehicle would not permit towing. With my family, three dogs, and travel trailer stranded 800 miles from home, this option was not viable. As a result, I was effectively forced to trade in my truck and purchase a replacement vehicle to safely return home. Manufacturer Awareness and Complaint History GMC has demonstrated awareness of this issue through service bulletins, widespread owner reports, and media documentation addressing transmission valve body failures and parts shortages. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

Filed Sep 11, 2025 · Transmission · 44,546 miles · WV

The contact owns a 2023 GMC Sierra 2500. The contact stated that while driving approximately 35 MPH, the vehicle went into LIMP Mode, and the message "Service Transmission" was displayed. The vehicle was taken to the dealer, where it was diagnosed that the transmission valve body rod had failed. The valve body rod was replaced. It was unknown whether the vehicle was repaired. The vehicle remained at the dealer. The manufacturer was not notified of the failure. The failure mileage was approximately 44,546.

Filed Sep 7, 2025 · Transmission · MO

Bought a 2023 gmc sierra 2500 duramax. Went into limp mode took it to dealership the transmission was bad so they replace transmission after 3 month of dealer having my truck . Got the truck back still having issues with transmission not shifting right and the rear tires locking up at highway speeds .

Filed Sep 4, 2025 · Transmission · TX

The transmission control mod is bad. This is a persistent problem and that's why it is on back order for up to a year. It is unethical to not issue a recall as customers have to continue to pay for the vehicle while not getting a replacement of equal capabilities. I bought a 3/4 ton truck to haul for work, not getting something that can do the same while a pay $1000+ a month is wrong. For the federal safety agency not to get involved, issue some sort of recall, and allow GM to continue to take people's money while their vehicles depreciate is wrong. Is this so the government can get paid back from GM for the bailout 15 years ago?

Filed Jul 17, 2025 · Acceleration, Transmission · OH

This issue is pertaining to the valve body in my 10-speed transmission. While I was traveling home, the truck experienced a “wheel lockup”. The transmission shifted down aggressively, then putting the truck into limp mode. I had to travel the rest of the way home with a max speed of 35 mph. I have been without this truck for 3 months waiting on parts. This is absolutely unacceptable from gm. Extremely unsave.

Filed Jul 9, 2025 · Transmission · GA

While driving the vehicle, I entered onto the interstate, as I accelerated into the flow of traffic, (approximately 45-50 mph) my truck suddenly and unexpectedly jerked and “clunked” extremely hard, I thought I had ran over a large object, approximately 5 seconds later it jerked and “popped” loudly. At that time the reduced engine power and check engine light came on causing my vehicle to suddenly slow down to 20 mph and almost being rear ended by a tractor trailer truck traveling the speed limit that had to hit his brakes e trebly hard to avoid a rear end collision. After removing my truck from the flow of traffic, I turned it off, exited the vehicle to see if I had ran over something, I did not. Cranked it up, no signs on the dash, as I started back to the travel lanes, it “surged & jerked” the reduced power and check engine light came back on. Once I got the truck to the dealership, the service manager informed me he knew exactly what it was, the transmission valve body was no longer good. He also informed me that my truck was now number 28 in line just at that dealership for the same issue and repair, then added that GM is out of stock on the parts and back order status.

Filed Jun 27, 2025 · Transmission · IN

The contact owns a 2023 GMC Sierra 2500. The contact stated while driving 35 MPH, the vehicle gear shift was shifting independently, and the contact noticed the vehicle was shaking and the vehicle went into limp mode. The check engine lights illuminated. The contact pulled over to the right side of the road turned the vehicle off and then turned the vehicle back on and the failure persisted. The contact the gear shift was stuck in fifth gear. A dealer was contacted. The vehicle was taken to the dealer where it was diagnosed that the valve body needed to be replaced. The vehicle was not repaired. The manufacturer was notified on the failure and opened a case. The contact was referred by the manufacture to report the failure The approximate failure mileage was 50,823.