2021 GMC Sierra 1500: stuck in gear or won't shift

Filed Oct 30, 2026 · Engine, Steering · 34,000 miles · AK

The contact owns a 2021 GMC Sierra 1500. The contact stated that while driving 45 MPH, there was an abnormal knocking sound coming from the vehicle. The vehicle started hesitating, and there was a loss of power that became worse over time. Additionally, the “Service Engine” and “Power Train” warning lights were illuminated. The messages “Loss of Steering Assist - Be Alert” and “Service Parking Brake” were displayed. The following day, the vehicle was driven in LIMP Mode to the dealer and was diagnosed with engine failure. The contact stated that there was an ongoing the federal safety agency investigation associated with the 6.2L engines. The failure mileage was approximately 34,000.

Filed Oct 15, 2026 · Engine · 110,900 miles · KY

The contact owns a 2021 GMC Sierra. The contact stated that while driving at 60 MPH, a reduced power mode warning message unexpectedly illuminated, and the vehicle unexpectedly entered limp mode. The contact stated that the temperature gauge indicated a high temperature and the vehicle was overheating during the failure. The vehicle was taken to the dealer, where it was diagnosed that the control valve had failed and needed to be replaced. The vehicle was not repaired. The dealer informed the contact that this was a known failure and escalated the issue to the manufacturer for further assistance. The contact stated that the failure was associated with Technical Service Bulletin (TSB) N252508340 and believed the repair should have been covered under warranty. The manufacturer was made aware of the failure via telephone and website. The contact was also referred to the federal safety agency for further assistance. The approximate failure mileage was 110,900.

Filed Sep 30, 2026 · Engine · IA

There is an known issue with the coolant control valve that causes the truck to enter "limp mode" that dangerously reduces the engine power. The part is not recalled but there is a special extended warranty, N252508341, up to 15yrs or 150,000 miles for 2021-2022 GMC 1500 trucks but my VIN is excluded from this for some reason. I would like this investigated.

Filed Sep 28, 2026 · Transmission · NY

The transmission overheats on this vehicle shutting the vehicle into “limp mode” this is extremely dangerous when at interstate/highway speeds and the vehicle slows it self down to a dangerously low speed and all other vehicles around are traveling at a high rate of speed, this has happened twice, it has also happened while in back roads and tractor trailers have had to swerve to avoid a collision.

Filed Sep 28, 2026 · Electrical, Engine · 98,000 miles · OK · 1 injury

The contact owns a 2021 GMC Sierra 1500. The contact stated that while the vehicle was parked, the battery charge indicator to zero. The vehicle lost motive power, and the vehicle was unable to exceed 30 MPH while driving. The vehicle was driven in LIMP Mode. The battery saver mode message was displayed before and during the failure. The vehicle then failed to restart. The vehicle had been repaired a year prior to the failure. The contact's blood pressure became elevated due to the issue. The failure mileage was approximately 98,000.

Filed Aug 28, 2026 · Engine · 81,000 miles · OK

The contact owns a 2021 GMC Sierra 1500. The contact stated that while driving at 60 MPH, the vehicle began to shake uncontrollably. A knocking sound was heard from the engine, and the vehicle entered limp mode. No warning lights illuminated. The contact was able to coast the vehicle to the residence. The vehicle was later towed to the dealer, where it was diagnosed that the engine failed and needed to be replaced. The contact associated the failure with the federal safety agency Campaign Number: 25V274000 (Engine and Engine Cooling). The vehicle was not repaired. The manufacturer was notified of the failure and informed the contact that the VIN was not included in the recall, and the contact was advised to file a complaint with the federal safety agency Hotline. The failure mileage was 81,000.

Filed Jun 17, 2026 · Engine, Fuel system · MI

While driving my vehicle, the engine and transmission lost power and the check engine light came on. The vehicle went into limp mode and engine propulsion was limited. Had I been traveling at a faster speed, this would have been very unsafe. After coming to a stop, placing the transmission in reverse did not move the vehicle and there was a grinding noise. I was able to savely move forward in limp mode, but the shifting was harsh. I was able to find an empty parking lot to safely park. The truck was towed to Jim Winter dealership in Jackson MI for inspection.

Filed May 30, 2026 · Driver assistance, Engine · FL

The truck randomly will not detect that it was shifted into park. Shifting between gears and back to park does not automatically fix the the issue and has taken up to 10 mins to turn the truck off. The adaptive cruise controls stopped working and can still use regular cruise control. Just not adaptive. It appears greyed out. The truck has thrown the error code: P1098, Engine Coolant Control Valve Position Sensor Minimum Stop Performance. The truck would go into limp mode until the error was cleared. This error has appeared 4 times over the past five months. The most recent date of it happening was today. 06/30/2026

Filed Mar 24, 2026 · Electrical, Engine · 75,000 miles · TX

The contact owns a 2021 GMC Sierra 1500. The contact stated that while driving approximately 50-65 MPH on an incline, the contact believed that the transmission was slipping or there was a misfire coming from the engine. The contact stated that the vehicle failed to restart automatically after the engine AUTO Start/Stop system was engaged after a complete stop. Additionally, the contact stated that after driving for a while, the vehicle went into LIMP Mode. The check engine warning light and other warning lights were illuminated. The vehicle was taken to the dealer to be diagnosed. The contact related the failure to GM Campaign Number: N252515590 (Corroded Ground Strap); however, the dealer had informed the contact that the vehicle was not covered because the VIN was not included and there was no warranty coverage on the vehicle. The vehicle was not yet diagnosed or repaired. The manufacturer was notified of the failure and referred the contact to the federal safety agency Hotline for assistance. The failure mileage was approximately 75,000.

Filed Feb 20, 2026 · Engine · 119,000 miles · TX

The contact owns a 2021 GMC Sierra 1500. The contact stated that while operating the vehicle, the check engine warning light illuminated and remained illuminated. While driving at various speeds, the vehicle entered LIMP Mode, causing the vehicle to decelerate. Additionally, the radiator fan was continually activated while operating the vehicle. The vehicle was taken to the local dealer, who diagnosed that the coolant control valve was inoperative and needed to be replaced. The vehicle was not yet repaired. The manufacturer was notified of the failure, but no assistance was offered. The failure mileage was 119,000.

Filed Jan 25, 2026 · Transmission, Wheels · LA

4 months after bring my truck back to the dealership for a body valve issue on the 10 speed transmission. The truck went into limp mode while I was driving.

Filed Jan 20, 2026 · Engine · MO

For the second time since I have owned the vehicle that was purchased brand new. The engine seized during driving on the highway and began making loud noises that was knocking and jerking the vehicle. The issue occurred initially around 15,000 miles and was diagnosed as lifter failure, was repaired and returned in July 2022. At 64,000 miles on January 15, 2026, while on an interstate the engine did the same thing and the vehicle went into limp mode. It has been diagnosed as lifter failure this second time and is awaiting appropriate repairs. Both incidents put myself in passengers at danger due to the nature in which the vehicle entered limp mode on the highway.