Which parts fail
Components named in complaints (accelerator pedal, throttle, sudden acceleration, cruise control).
Mileage when the problem started
Owner reports
Selected complaints filed with NHTSA by 1999 GMC Sierra owners, lightly cleaned up (personal details are redacted by NHTSA).
Tl contact owns a 1999 GMC Sierra. While driving approximately 40 MPH, the contact depressed the brake pedal but the vehicle did not slow down; therefore, he used the emergency brake to stop the vehicle. He then noticed brake fluid on the floor of the vehicle. The vehicle was towed to a local repair shop. The contact received minor bruises due to the sudden stop. The vehicle had not been repaired at the time of the complaint. The failure and current mileages were approximately 142,000.
Accelerator pedal sticking when attempting to accelerate, the gas pedal sticks requiring more than average force to engage. This becomes a dangerous situation in parking lots or close quarters, such as in traffic as it May lead to a collision with nearby vehicles or woes yet, a nearby pedestrian. This condition started slowly and gradually became worse until it happens at almost every initial accelerate from start up.
While applying the accelerator pedal the pedal stuck, and vehicle failed to accelerate. Vehicle was taken to the dealer for inspection, and mechanic determined that the accelerator pedal needed to be oiled. This was the same excuse given by nultiple dealerships and consumer's extended warranty company. Consumer claimed had many cars and never was there a need to oil the accelerator.
I am having trouble with my throttle when attempting to accelerate from idle. It feels as though something is sticking, then suddenly releasing once enough pressure is applied to the accelerator pedal. This results in the vehicle lunging forward every time.
While pulling inside of the driveway and coasting along, engine just roared up and vehicle accelerated. Vehicle jumped over landscape timbers and hit basement wall. Also, front brakes locked up, but back wheels were still moving and in motion.
Gas pedal sticks occasionally when accelerating. Driver must apply force to pedal causing truck to lunge. I am just putting today's date as the incident date, however it has been happening since I purchased the truck.
Throttle plate sticks at idle requiring additional force to release. This caused vehicle to fail to come out of idle at red lights and intersections. Dealership charged me repeatedly for cleanings and argued with me regarding TSB's about the throttle. I was told I was not supposed to have that information and it didn't matter. I was told throttle body systems are normal maintenance and the throttle body needed replacement every 10,000 miles. The drivers seat (manual) would unexpectedly release throwing me into the steering wheel. Plastic part broke from seat track. Dealership failed to fix, damaged the seat further trying to grind on the track and hammered seat track in the closed position to force the seat from moving. Charged me for damaging the seat. …
GMC Sierra has been in shop to many times to keep track of. Truck also has a problem with sticky throttle body which has been dangerous.GMC gave extended warranty in 2000 bacause of problems also issued customer appreciation certificate if I wanted to buy new GM product.service manager told me to cut my losses and but a new one.GMC will not do a thing for me. Contacted nys attn. General about problems.GMC now has their legal core calling me at home . I have asked them to buy vehicle back research the parts and assembly to protect other owners. GMC says sorry . I asked them how they could warranty rust thru for 100,000 but could not protect ABS from corrosion, GMC response was hey you live in new york state. And they are under no financial obligation what so ever
When attempting to pass another vehicle on an incline at speeds of 55mph to 65mph the transmission shifts into second gear and revs the engine up to 4500 rpms and doesn't increase the speed because it is running at its peak speed in second gear causing me to have to let up on the accelerator and try to get back behind the vehicle I was trying to pass.this same downshifting also occurs when using the cruise control.the dealer did not want to test drive the vehicle on a similarly inclined road to duplicate the problem because he didn't have another vehicle like mine to compare it to.the defect in this transmission could easily put me in a head accident situation and needs to be addressed immediately.
Accelerator pedal sticks at idle takes great pressure to move. When it breaks free pedal goes full travel (to floor) idle to full throttle immeadiately. Very rare occurance starting 2 years ago, beginning to be very frequent when engine is cold and starting to occur even when engine is warm. Very dangerous, as pedestrians and other vehicles are at great risk of collision as vehicle accellerates rapidly. Please look at this as it appears to be a very common occurance from the auto forums I have looked at. Vr/ lcdr robert c buzzell, us navy. Dt
NHTSA investigations
Throttle sticking
There is no summary currently available
Throttle sticking closed
This investigation involves the general motors corporation (GM)throttle body (tb) utilized in model year (my) 1999-2002 silverado, sierra, tahoe, suburban, avalanche and yukon (subject vehicle(s)) with 4.8l, 5.3l, and 6.0l engines. The tb valve May intermittently stick in a closed position.in such a situation, an operator May apply additional accelerator pedal force to increase engine speed.the application of…
Acceleration complaints in other Sierra years
Frequently asked questions
How common are acceleration problems on the 1999 GMC Sierra?
NHTSA has 39 complaints about the speed control & acceleration of the 1999 GMC Sierra, 7% of the model year's 600 complaints. The component named most often is accelerator pedal (20 mentions).
Is there a recall for 1999 GMC Sierra acceleration problems?
No. NHTSA lists no speed control & acceleration recall for the 1999 GMC Sierra, though it has 5 recalls for other components. If the problem is widespread, a repair may still be covered by an extended warranty or a manufacturer service bulletin — ask a dealer.
At what mileage do 1999 GMC Sierra acceleration problems start?
Half of the complaints with a recorded mileage happened before about 32,000 miles, and 33% before 25,000 miles.
Is it dangerous?
Owners linked 2 crashes, 0 fires and 1 injury to speed control & acceleration problems on this model year. If you notice symptoms, have the car checked before driving further.
Source: U.S. National Highway Traffic Safety Administration (NHTSA) — owner complaints through October 20, 2026, recalls and defect investigations; fuel economy from the EPA. Complaints are unverified reports and are not proof of a defect. How we rate model years.