Over the last 3 years we have had ongoing issues with our truck going into limp mode. We have spent thousands of dollars at dealerships and mechanics trying to troubleshoot the issue. Several occasions while trying to merge onto the freeway the truck would slip into limp mode causing us to have other drivers slam on their breaks almost hitting us. We had 2 cars in January of 2023 veer off the side of the road. We pulled over and thankfully they missed hitting one another. We just couldn't speed up to get out of their way. We cant believe their hasnt been a safety recall on the TCM for these trucks. GMC started doing Service bulletins in 2013 about the TCM causing the limp mode issues. There are dedicated facebook groups with over a 1,000 followers who are experiencing the same issues with these TCM's. Someone is going to die if they havent already. Several collisions, involving the years affected, are being re-investigated to determine why the vehicle slowed abruptly causing a fatal accident. A class action lawsuit is gaining momentum because GM will not do anything about the TCM.

- Sequim, WA, USA

While the vehicle was in motion on a city street, the fuel management system failed almost causing me to be in an accident. The engine sounded like it was blowing up with metal on metal sounds, loss of control and power. I had my vehicle transported to an authorized mechanic and he determined the fuel management system had failed and the engine would have to be rebuilt. I spent over $3000 to have it repaired and it still leaks oil and has issues with providing correct engine power and control. It is not safe nor dependable.

- Tipp City, OH, USA

Active fuel management system failed as I was driving down the street. Engine stuck in 4 cylinders. Sounded like it was going to blow up it was rattling so loud. Rapid loss of power and torque as a result.

- Tipp City, OH, USA

Life threatening safety problem: While merging into high-speed traffic on [xxx] in charlotte nc, my 2010 GMC Sierra rapidly decelerated from approximately 65 mph to 10 mph. Two tractor-trailer trucks going at least 70 mph narrowly avoided rear-ending me. Only the lack of traffic on there right side prevented a major disaster. My dashboard showed a engine power is reduced/service traction control/service sabilitrak warnings, and the engine idled erratically as I maneuvered off the to the side of the highway. There was no throttle response. This engineer design put the safety and lives of many at risk by dumping engine power to what is the equivalent of slamming on the breaks at high speed without warning. In April 2018, approximately 8 months ago, I had the exact same problem while driving in my neighborhood road. An authorized dealer completed a $679 replacement of my throttle-body gasket and gas pedal assembly (see attached receipt). The truck drove without issue until this incident. I didn't think this was a serious safety issue because it did not happen at high speed. Now, I have the same problem occurring at a high rate of speed on the highway. Finally, the dealer explains that there are multiple issues that can cause this malfunction and they are now completing another $600+ repair, replacing multiple parts (repair bill not yet available). Based on this troubleshooting and repair history, a consumer is never getting a guaranteed permanent fix for this problem. This begs the obvious question, of why is there a designed malfunction that jeopardizes safety in this manner? parts of this document have been redacted to protect personally identifiable information pursuant to the Freedom Of Information Act (FOIA), 5 U.S.C. 552(B)(6).

- Charlotte, NC, USA

The contact owns a 2010 GMC Sierra 1500. While driving approximately 40 mph through a snow bank, the check engine and traction warning indicators illuminated. The stability track indicator signaled the system to be off and needed servicing. The contact had not taken the vehicle to the dealer. The contact spoke with a certified mechanic who stated that the throttle body, brake sensor switch, and faulty air intake system failed and needed to be replaced. The vehicle was not repaired. The manufacturer was made aware of the failure and directed the contact to NHTSA and/or the dealer. The VIN was unknown. The approximate failure mileage was 11,458.

- Riverhead, NY, USA

The contact owns a 2010 GMC Sierra 1500. While driving approximately 55 mph, the traction control and stabilizer warning indicators illuminated. The engine made a knocking noise and the vehicle failed to accelerate at the desired rpms when the accelerator pedal was depressed. The contact took the vehicle to jim faulk motors (1201 N 2nd St clinton, mo 64735; 660-956-0076 or 877-819-4482) where it was diagnosed that the engine failed and needed to be replaced. The vehicle was repaired, but the failure recurred. The contact returned the vehicle to the same dealer where it was diagnosed that the engine failed and needed to be replaced again. The vehicle was not repaired. The manufacturer was made aware of the failures and stated that, due to the warranty expiring, they were unable to assist with the repair. The approximate failure mileage was 178,000.

- Knob Noster, MO, USA

At ~ 54,000 miles, the vehicle experienced increased oil consumption and lost compression on two cylinders. This vehicle has only been subjected to highway mileage of about 30 miles/day on average and has been properly maintained. The damage was to the extent that cylinders had to be replaced and it took the dealership 25 days to repair. A coworker had the same engine issue on his Chevrolet Silverado with the same 5.3 liter engine at ~ 45,000 miles. A cursory search of the internet will reveal that this is not an isolated incident. The overwhelming majority of owners comments that I have researched believe that it is caused by the active fuel management system failing to properly lubricate components when the engine cycles between 4 and 8 cylinders. GM disavowed any knowledge of these incidents when contacted. The service department of my local GMC dealership disavowed any knowledge also although I presented them over a dozen pages of GM owners group web pages with description of the same engine failures. However, when their mechanic was questioned as to whether he was repairing the problem or merely exchanging damaged parts, he replied "it won't happen again, we do this all the time". this tells me that my vehicle is not the first that they have seen with this problem.

- Madison, AL, USA

Engine light came on - took to dealer - was told it was PO455 code evap failure - evap vent valve stuck open. Was told that it was a known problem but not covered by GMC - cost $501.17

- Ronkonkoma, NY, USA

While driving down a steep hill, lost engine power and truck speed was dramatically reduced. Dash warning "reduced engine power" displayed. Could not accelerate. This could have resulted in a an accident because this situation caused difficulty controlling the vehicle.

- Wenatchee, WA, USA

As I was driving the truck seemed as if it turned off, all the gauges went down appearing of the truck was off and not running. The truck was still running, but the engine did not have power or acceleration. Continued to drive till I was at a safety zone. Turned it off and did not want to start no more I took the battery cable off and put it back jump start it and everything went back to normal.

- Santa Teresa , NM, USA

Saturday, July 27, 2013, our 2010 GMC Sierra K1500 caught fire and was completely destroyed as my husband was driving on the interstate. As smoke began to fill the cab and the "check engine" light came on, he attempted to brake so that he could escape, but the brakes were gone, and the brake pedal went all the way to the floor. Imagine his terror as he realized that at age 65, he may have to jump out of the truck or be consumed by a fire. He was able to down-shift to slow the truck enough to use the emergency brake to get the truck stopped just in time to escape from the truck and get far enough away to avoid bodily injury as the truck and our belongings burned completely. We are gravely concerned that the truck, which was purchased three years ago this month, and had only 18,000 miles on it, clearly was a risk to our lives and the lives of others. We have three adult children and seven grandchildren & often had one or more of them with us as we traveled in this vehicle. Had we needed to unbuckle the babies from their car seats and/or assist the toddlers in getting out, the outcome may have been very different, and it haunts us to know that this could have been the case. All had ridden in this truck in the weeks preceding yesterday's fire. As my husband headed home to Montana at the completion of his travel to visit our children and grandchildren, he ascended, then descended "lookout pass" on I-90 at the Montana/Idaho border - a pass that is steep and very busy with summer vacation travel as well as consistent heavy semi-truck travel. The curves on lookout are treacherous: The rate of accidents and semi-truck rollovers on the curves is high without an extraordinary event such as a burning vehicle. If our truck had caught fire even three or four miles earlier as he was descending the pass, the outcome is almost unthinkable.

- Kalispell, MT, USA