2023 GMC Sierra HD owner complaints

I was driving on the interstate and had just exited to refuel. As I was re-entering traffic, I accelerated to merge, and suddenly, as I was about to pull in, I felt and heard a massive metallic crash, like the entire transmission had dropped. The engine sounded abnormal, and immediately, the dashboard flashed a warning: 'Engine Power is Reduced.' The check engine light came on, and I got messages saying the transmission needed service and to schedule an appointment. I called my dealership and took it in as soon as possible. After they held the truck for a while, the service manager told me a critical part was on indefinite backorder with no fulfillment date. He handed back my keys, saying they'd reach out when it arrived. I asked if it was safe to drive, and he said yes. Later, driving fro

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.

2023 GMC Sierra Duramax Diesel with 10 speed Allison Transmission with 28,000 miles can't be driven. Currently at the dealership due to a transmission valve body problem, codes P0700 & P0747. While driving I felt a hard shift and the truck jerk. The engine light came on and my truck went into low power mode. Let it sit over night and truck would shift fine. This happened 3 times over a 1 month period. After getting to the Chevy dealer they told me the issue is with he valve body and said they have been having multiple trucks come in with the same problem. They have a truck in there since May (4 months!) They told me there is no ETA for the part. I've read this is a common issue happening on 2023 & 2024 trucks like mine. I've read that the problems have been going on for over 1 year. This i

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 .

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 NHTSA 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?

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.

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 & jer

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 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.

The valve body inside the transmission has failed and GM has known it to fail but they have done nothing about it. My vehicle has been in the shop for 2 months because of it and “parts are on back order” it’s terrible i’ve bought this vehicle in august and it’s constantly been inside the shop for various issues. My transmission lost 7th gear and it came to an immediate stop in the road because of it. tires screeching and all. truly embarrassing that you can spend 83,000$ on a truck and it be such a peice of junk.

I rely heavily on this vehicle for my business and within 1 year of ownership, the vehicle broke down on the highway allowing it to only run @ 30mph. After finally locating a dealer who could evaluate the vehicle in less than 1 week, I was informed that the part was unavailable and they indicated, "it could take 1 month or 3 months to receive." Following multiple conversations, I was forced to open a claim with GM Customer Care. While trying to get information, I was, at one point, told that "although the code indicates failed transmission control module, it doesn't happen all the time and if I wanted to drive it I could come and take it until the part arrives." That really told me alot about how GM representatives view SAFETY while when it happened, I was on Interstate and nearly got

The contact owns a 2023 GMC Sierra 2500. The contact stated while driving approximately 40 MPH, the vehicle shook abnormally twice and then switched to Low Power Mode. The contact stated there was no warning light illuminated. The contact had the vehicle towed to a local dealer, where it was diagnosed and determined that the transmission valve body needed to be replaced. The contact stated that the valve body had failed within one and a half year. The contact requested that the entire transmission be replaced. The manufacturer was informed of the failure and declined to replace the transmission. The vehicle was not repaired. The failure mileage was approximately 42,000.

Two times with my truck, the transmission has locked up solid while towing a heavy load almost causing my load to shift and wreck my truck in traffic. It happened at 60k miles and again at 68k miles. The truck shutters and then locks up solid on the transmission, then after a second of sliding, it releases and goes into limp mode. This is a serious issue when it is uncontrollable. It felt like my trailer had broken loose and slammed into the cab when it happened. I'm sure it wasn't good on the truck in general. A code scanner read P0747 code and it appears that GMCs recall does not cover my truck in another recall for the same issue with 20-22 model trucks. It is happening all the way up to the 25 year models from what I read.

The contact owns a 2023 GMC Sierra 2500. The contact stated that while driving at an undisclosed speed, the contact smelled an abnormal odor. The vehicle was taken to the dealer; however, no failure was found. The contact stated that while driving at an undisclosed speed, the contact heard an abnormal sound and smelled an abnormal odor. The vehicle was taken back to the dealer, who diagnosed the vehicle with an oil leak; however, the dealer was unable to determine the location of the leak. The manufacturer was not made aware of the failure. The failure mileage was approximately 6,000.

Shift to park message displayed while attempting to shut off engine after shifter was in the park position, accessory would not turn off even after driver door opened and could not leave vehicle.

The contact owns a 2023 GMC Sierra 2500. The contact stated that while the vehicle was in reverse(R), the split-screen view of the overhead of the vehicle and the rear of the vehicle were distorted or was not showing an image on the display screen. The contact stated that the failure was intermittent but was a recurring failure. The contact had taken the vehicle to a local dealer, where it was diagnosed and determined that there was no failure of the camera found. The contact stated that the dealer had removed and re-installed the camera. The vehicle was repaired; however, the failure reoccurred. The manufacturer was informed of the failure. The contact researched online and related the failure to TSB Number: 23-NA-169. The failure mileage was approximately 35,000.

I sent a certified 3 page letter along with 4 pages of supporting documentation on April 25th, it was received and signed for on 4/30 at 10:16 am. I have still not received a response. I called to follow up and the reference number is #1516488, they told me to file the case online. I have copy of the letter I can resend via email or upload here.

Defective valve body We took in our vehicle for issues with the engine. We were not able to drive it over 50 mph it only has 22,000 miles. The dealership has had the vehicle since August 13th. They have had the vehicle for 9 weeks. They said that neither them or customer [XXX] (CASE # [XXX]). Can locate a valve body, to replace the defective one. We were made aware that we had an issue when our check engine light came on. We proceeded to have a diagnostic done thru on-star. Then immediately took it to the dealership for repair. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

When dealer took apart my rear brakes the parking brake shoe lining was un bonded from the shoe 26,000 miles and seems to be a defective part

Bought the truck brand new. within a week the service trailer brake warning light came on. has been to the dealership 3 times and they still cant fix it. This affects towing of the trailer with no trailer brakes.