2020 GMC Sierra 2500 Powertrain (other) Problems

While driving down a highway doing between 45 and 55 mph the transmission suddenly and completely faulted causing the truck to come to a complete stop. Just enough power to get to the shoulder luckily. The transmission had basically completely blown out, fluid everywhere. The insurance company did not find any comprehensive damage. The entire transmission needs to be replaced. There were no indicators showing any problems, no alerts, no warning whatsoever. Mechanics said there was a lot of metal coming out of the transmission. The truck is currently in a mechanic shop awaiting the new transmission, so at this time it is available for inspection. The safety issue here is that it happened on a busy highway, and the vehicle was no longer drivable so it needed to be towed causing more time spent on the side of the road.

NHTSA ID

11723197

Incident

Feb 18, 2026

A couple times I heard loud clanking coming from rear brakes. One time in particular I was trying to stop and it felt line someone had ran into my truck but must have been the rear wheel locking up

NHTSA ID

11718162

Incident

Jan 30, 2026

Torque converter in my transmission we out, causing my gears to grind and lose power. Slight rumbling sound under the front passenger seat, First dealer (Palmen Motors, Kenosha WI) told me there was nothing wrong with the vehicle and no transmission error codes exist. Second dealer (Parks GMC, Greenville SC) indicated that i need a complete new transmission. Part is on backorder for the last 4 weeks and I am without my vehicle. No ETA for new part or any information on why it failed prematurely.

NHTSA ID

11693346

Incident

Jun 13, 2025

The contact owns a 2020 GMC Sierra 2500. The contact stated that while driving approximately 70-80 MPH, the transmission downshifted, and the rear wheels locked up. The contact was able to coast to the side of the road. The contact was unsure if a warning light had illuminated. The vehicle was towed to the dealer, where it was diagnosed and determined that the transmission had failed and needed to be replaced. There were metal shavings found mixed in with the transmission fluid; however, the vehicle remained with the dealer unrepaired. The contact was informed by the dealer that the warranty had expired, and the vehicle could not be repaired. The manufacturer was notified of the failure but declined to assist in covering the cost of the repair. The failure mileage was approximately 166,000.

NHTSA ID

11679851

Incident

Jul 11, 2025

Mileage

166,000 mi

The contact owns a 2020 GMC Sierra 2500. The contact stated that while her husband was driving 30 MPH, the rear wheels locked up and the vehicle skidded to a complete stop. No warning lights were illuminated. The vehicle was towed to the dealer, who diagnosed a failure with the transmission. The contact was informed that the transmission had imploded and needed to be replaced. The vehicle was not repaired. After investigating the failure, the contact related the failure to NHTSA Campaign Number: 24V797000 (Power Train); the VIN was included but the vehicle had not been repaired. The manufacturer was not notified of the failure. The failure mileage was 125,000.

NHTSA ID

11671648

Incident

Jun 28, 2025

Mileage

125,000 mi

What component or system failed or malfunctioned, and is it available for inspection upon request? - Transmission Valve Body resulting in a P0700 & P0747 code. Yes currently installed in vehicle. How was your safety or the safety of others put at risk? - When the vehicle goes into a limp mode to protect the transmission and rear-wheel lock up, the truck shuttered and hard downshifted. Speed limit is restricted to 5th gear only. I've been instructed by GM to continue driving and using the vehicle until the problem happens again, knowingly putting myself and others at risk on a second failure that could happen at any time. Has the problem been reproduced or confirmed by a dealer or independent service center? Yes this is a common problem with a recall #N242454440, NHTSA 24V-797. Has the vehicle or component been inspected by the manufacturer, police, insurance representatives or others? Mine has been rejected by GM. Although I documented and photographed the failure codes, I cleared them from the vehicle in order to attempt to safely get to the dealer and prevent further damages. Were there any warning lamps, messages or other symptoms of the problem prior to the failure, and when did they first appear? At the time of failure yes, check engine light and codes from an engine monitor coinciding with the known problems. Engine speed / power was reduced to allow only 5th gear.

NHTSA ID

11668939

Incident

Jun 20, 2025

After the transmission recall was completed, I’m now having erratic shifting. Having the recall adding software monitoring for a hardware issue is inadequate. Now that I am out of warrentee, gm has not resolved the issue and now I am having shifting problems.

NHTSA ID

11661620

Incident

May 12, 2025

The contact owns a 2020 GMC Sierra 2500. The contact received notification of NHTSA Campaign Number: 24V797000 (Power Train); however, the part to do the recall repair was not yet available. The local dealer was contacted. The contact stated that the manufacturer had exceeded a reasonable amount of time for the recall repair. The manufacturer was not made aware of the issue. The contact had not experienced a failure. Parts distribution disconnect.

NHTSA ID

11658105

Incident

May 1, 2025

The contact owns a 2020 GMC Sierra 2500. The contact stated that the vehicle was under NHTSA Campaign Number: 24V797000 (Power Train) and the vehicle was repaired. The contact stated that after the recall repair, the transmission started shifting hard. The vehicle was taken to the dealer, and the contact was informed that the transmission module would reprogram and adjust independently. The contact stated that a week later, while driving approximately 45 MPH, the vehicle started to run rough, and the message engine power reduced was displayed. The transmission fault, parking brake system alert, service parking brake, and the check engine warning light illuminated. The vehicle was towed to the dealer, who diagnosed the vehicle and determined that the fuel injector was open, causing high resistance in the connector for cylinder #4. The transmission could not be diagnosed until the injector was repaired. The manufacturer was informed of the failure and opened a case. The failure mileage was 125,000.

NHTSA ID

11655399

Incident

Apr 7, 2025

Mileage

125,000 mi

ODI # 11646185 My truck on [XXX] leaked transmission coolant from the jumper line leak( which this part is recalled but not for my VIN #) $400.61 dollars and left me stranded in the middle of the highway and had to be towed. After the repair and checking the transmission was discovered it was ruined because of the leak. So now I have to have a new transmission installed at Jennings in Beardstown IL to the cost of $7363.39. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

NHTSA ID

11648985

Incident

Mar 2, 2025

Transmission not shifting correctly. Have had the recall software update. Two new valve bodies and still not shifting correctly. Transmission is known to lock up.

NHTSA ID

11648752

Incident

Feb 3, 2025

My truck had been sitting idling for about 20 minutes on a job site on flat level ground. I turn around for whatever reason and my truck is driving forward with on one in it but my dog. The truck ran into an out rigger on my crane. I had 3 of my employees there that witnessed this happen. I got into my truck and the shifter was in drive. Somehow my dog was able to shift my truck into drive from park while it was sitting idle. I have 3 eye witnesses as well as pictures of the incident. I have pictures but was no able to upload them to they portal.

NHTSA ID

11646739

Incident

Jan 10, 2025

The contact owns a 2020 GMC Sierra 2500. The contact stated while driving 30 MPH, the engine revved while the vehicle lost motive power in the middle of the road. The contact was unable to pull over to the side of the road. The vehicle was restarted but was undrivable. An unknown warning light was illuminated. The contact stated that while the vehicle was being towed, there was a significant amount of fluid leaking onto the ground. The vehicle was towed to Ryan's Repair, where it was diagnosed with a fractured transmission cooler line. The vehicle was not repaired. The mechanic related the failure to an unknown recall. The dealer was not notified of the failure. The manufacturer was notified of the failure, but no assistance was provided because the VIN was not included in the TSB. The failure mileage was approximately 112,000.

NHTSA ID

11646185

Incident

Mar 2, 2025

Mileage

112,000 mi

The contact owns a 2020 GMC Sierra 2500. The contact received notification of NHTSA Campaign Number: 24V797000 (POWER TRAIN); however, the part to do the recall repair was not yet available. The local dealer was contacted. The contact stated that the manufacturer had exceeded a reasonable amount of time for the recall repair. The manufacturer was made aware of the issue. The contact had not experienced a failure. Parts distribution disconnect.

NHTSA ID

11645276

Incident

Oct 24, 2024

The contact owns a 2020 GMC Sierra 2500. The contact received notification of NHTSA Campaign Number: 24V797000 (POWER TRAIN); however, the part to do the recall repair was not yet available. The local dealer was contacted. The contact stated that the manufacturer had exceeded a reasonable amount of time for the recall repair. The manufacture was made aware of the issue. The contact had not experienced a failure. Parts distribution disconnect.

NHTSA ID

11642616

Incident

Dec 24, 2024

The contact owns a 2020 GMC Sierra 2500. The contact received notification of NHTSA Campaign Number: 24V797000 (Power Train). After reading the context of the recall, the contact stated that the proposed remedy of a software update was not an adequate repair for the rear wheel lock-up failure. The contact stated that the safety of the vehicle could not be trusted and believed that the vehicle was unsafe to operate. The local dealer was made aware of the issue and confirmed the recall remedy. The contact was referred to the manufacturer for further assistance. The manufacturer was made aware of the issue and the contact proposed a buyback offer for the vehicle which the manufacturer denied. The contact was provided a case number. The contact had not experienced a failure. Parts distribution disconnect.

NHTSA ID

11641401

Incident

Dec 22, 2024

The contact owns a 2020 GMC Sierra 2500. The contact stated while driving 63 MPH, and towing a 15,000 lb. 5th Wheel RV, the contact heard the rear wheels make an abnormal squealing or chirping sound. The contact stated that the front end of the vehicle was pulling to the right. The contact adjusted the steering wheel to the left to compensate. The contact stated that the vehicle was losing motive power. The contact stated that the drive(D) symbol was flashing on the instrument cluster. The contact depressed the accelerator pedal; however, the vehicle failed to respond as intended. The contact exited the highway and stopped the vehicle. The contact had the vehicle towed to an independent mechanic. The mechanic scanned the vehicle but did not retrieve any fault codes. The mechanic researched online and informed the contact that the VIN was included in NHTSA Campaign Number: 24V797000 (Power Train) for a defective transmission control valve. The contact was referred to a dealer by the mechanic. The vehicle was not repaired. The contact had the vehicle towed to a local dealer who diagnosed the vehicle and determined that the transmission needed to be replaced. The contact was informed that the transmission was not covered for repairs if damaged while performing the recall repair. The vehicle was not repaired. The manufacturer was informed of the failure. The failure mileage was approximately 112,000.

NHTSA ID

11640707

Incident

Dec 28, 2024

Mileage

112,000 mi

The contact owns a 2020 GMC Sierra 2500. The contact stated while driving at an undisclosed speed, the accelerator pedal was depressed, and the transmission jerked. The contact stated that the transmission was skipping gear while shifting. The check engine warning light turned on and off. The contact received notification of NHTSA Campaign Number: 24V797000 (Power Train); however, the part to do the recall repair was not yet available. The local dealer was contacted. The contact stated that the manufacturer had exceeded a reasonable amount of time for the recall repair. The manufacturer was made aware of the issue. The failure mileage was approximately 114,000. VIN tool confirms parts not available.

NHTSA ID

11635928

Incident

Jan 7, 2025

Mileage

114,000 mi

The contact owns a 2020 GMC Sierra 2500. The contact received notification of NHTSA Campaign Number: 24V797000 (Power Train); however, the part to do the recall repair was not yet available. The local dealer was contacted. The contact stated that the manufacturer had exceeded a reasonable amount of time for the recall repair. The manufacturer was made aware of the issue. The contact had not experienced a failure. VIN tool confirms parts not available.

NHTSA ID

11634303

Incident

Oct 24, 2024

The contact owns a 2020 GMC Sierra 2500. The contact received notification of NHTSA Campaign Number: 24V797000 (Power Train); however, the part to do the recall repair was unavailable. The contact stated that the manufacturer had exceeded a reasonable amount of time for the recall repair. The dealer was contacted. The manufacturer was made aware of the issue. The contact had not experienced a failure. VIN tool confirms parts not available.

NHTSA ID

11631611

Incident

Oct 24, 2024

The contact owns a 2020 GMC Sierra 2500. The contact stated while driving approximately 65 MPH, the vehicle lost motive power. The contact stated that he had not depressed the brake pedal. The contact was towing a 20-foot flatbed trailer with a load of lumber of approximately 4,000 lbs. in weight. The contact stated there was no warning light illuminated. The contact pulled over with the vehicle still running and attempted to shift into drive(D) and reverse(R); however, the vehicle failed to respond. The contact stated that after shifting into drive(D), several unknown warning lights were illuminated. The contact had the vehicle towed to a local dealer; however, the vehicle was not diagnosed or repaired. The contact researched online and related the failure to NHTSA Campaign Number: 24V797000 (Power Train). The manufacturer was informed of the failure. The failure mileage was approximately 100,000.

NHTSA ID

11626451

Incident

Nov 16, 2024

Mileage

100,000 mi

There is an issue that is causing the batteries to die. This in return causes the Vehicle to go into Limp home mode with no warning. The "issue" was supposed to be resolved by the Dealer in March 2022. The resolution was that one battery was bad. The vehicle is equipped with two batteries. Each of which is sufficient to run the vehicle. A single battery failure should not have caused the truck to have a power limitation. Furthermore the issue was not resolved and General Motors and the Local dealership refuse to continue to work on the issue. This is even after filling complaints with BBB. As of November 2022 the issue has cause both batteries to go bad. The dealer has refused to work on the vehicle and it has been out of service for more than 30 days. Secondary issue. The dealer has refused to work on the vehicle but computer is locked by GM so that only GM equipment can see full scope of codes. This means I can not have third parties work on the vehicle. This is can get the vehicle stuck in areas where there is not GM facilities and GM will not provide any assistance as it is not under warranty. This has also prevented me from finding the actual resolution to the problem.

NHTSA ID

11499881

Incident

Mar 10, 2022