The vehicle would shudder when trying to accelerate. I almost was hit by a semi truck trying to merge onto the freeway. Made an appointment with the mechanic then a couple days later I was at a stop sign and the vehicle would not accelerate at all. I placed in park the tried shifting back into drive and still nothing. I had to turn the vehicle on and off twice before I was able to shift it in drive an it actully would accelerate. Even then it would shudder and not accelerate fully. Very dangerous. Just hit 100k miles. GMC Certified Mechanic said the transmission is shot and needs to be replaced. Cost to replace over $6,000 Bought the truck in 2020 for $35,500 and just paid it off.

- Redding, CA, USA

Lost of acceleration at a set speed the throtal stopped to increase the speed and just flooped to floor. When the speed slowed to a set point, acceleration control returned. When it hit the high setting it again lost control to increase speed. This happened every time I reached the drop off speed. Why dose this happen"?" one time I was on a highway passing two trucks on a upgrade when this happened the #2 truck went to pass #1, the #2 truck was on my rear thank god acceleration returned. I reported this occurance to manufacture & to "NHTSA" over a year ago. I got "no" answers or responce from anyone!!!

- Feasterville Trevose, PA, USA

The contact owns a 2017 GMC Sierra 1500. The contact stated that while accelerating at 85 mph, the vehicle independently decelerated to 70 mph without warning. The contact stated that the throttle no longer operated as needed. The contact had taken the vehicle to faulkner Buick GMC trevose (4427 E street rd, feasterville-trevose, pa 19053) on two occasions however, the mechanics were unable to diagnose the failure. The manufacturer was also notified of the failure and informed the contact that they had never heard of such a failure. The contact then spoke to an independent mechanic who informed him that the defect may be linked to a speed sensor and a computer malfunction. The contact then took the vehicle to another independent mechanic who reprogrammed the computer software. The vehicle was repaired. The failure mileage was approximately 19,906.

- Feasterville-Trevose, PA, USA

When stationary I pushed in on the gas throttle to go it didn't go so I pushed in a little more and it accelerated to fast then like it jumps. It also is shaking at certain speeds.

- Rainsville, AL, USA

The contact owns a 2017 GMC Sierra 1500. On several occasions, the accelerator pedal was depressed; however, the vehicle failed to respond. On one occasion, the gear shift lever was placed in reverse and the accelerator pedal was depressed; however, the rpms revved without the vehicle responding. The vehicle was taken to greg lair Buick GMC (16200 canyon dr, canyon, tx 79015, (806) 553-5706) on two separate occasions; however, the transmission technician was not available to diagnose the vehicle. The vehicle was not repaired. The manufacturer was not notified of the failure. The approximate failure mileage was 33,042.

- White Deer, TX, USA

The truck lurches forward as if the accelerator is being depressed while coming to a stop obviously while depressing the brake. This causes dangerous situations every day in traffic. I have not found any solutions to the problem online. Reprogramming computer and replacing other speed control modules has not solve the problem for other drivers.

- La Grange, NC, USA

The contact owns a 2017 GMC Sierra 1500. While driving 75 mph with the cruise control activated, the vehicle decelerated without warning. The vehicle was pulled over to the side of the road, waited approximately twenty minutes, and restarted the vehicle. The vehicle was taken to findlay Chevrolet Buick GMC (928-754-3400, located at 2565 laughlin view dr, bullhead city, AZ 86429) to be diagnosed, but the failure could not be duplicated. The manufacturer was made aware of the failure and stated that it would be investigated. The contact was not called back. The failure mileage was approximately 26,000.

- Bullhead City, AZ, USA

Vehicle has hard shift at 5-6 mph. Dealer stated could not find issue, and reflashed tcm.approx month later, at 10K miles, truck hard shifted from red light on highway, once up to 45 mph, shutdown. Steering wheel locked up, no brakes, no control of vehicle at 45-50 mph.dealer kept for one week, stated loose cable on starter from battery. Exactly 1K miles later (5 weeks), now at 11K miles, truck hard shifted at 5-6mph, and at 45-50 mph truck tried to shift in 4WD. All lights on dash came on as a result. Dealer has currently had the truck for two weeks and can not find issue. They supposedly consulted GM, and instead of sending an expert tech to help dealer find issue, advised dealer to replace ECM. Replacing ECM is the general answer to not sure what is wrong. This truck is a safety issue, as when it shuts off going 45-50 mph there is no control or brakes operational on the vehicle. GM will replace the ECM, and just like right now, will not be able to replicate the problem, and expect me as the consumer to take delivery back of the vehicle. Currently all of my documentation is in the dash of this truck, at the dealership. Trying to determine how myself as the consumer can help ensure this safety issue is corrected, and not passed on.

- Milner, GA, USA