Table 1 shows one common electrical system related problems of the 2026 GMC Sierra 1500.
| Problem Category | Number of Problems |
|---|---|
| Electrical System problems |
Three different times now (most recent: 10/22/2026), I have had my truck completely shut off when coming to a stop on the highway/interstate. I always have auto start/stop disabled when I drive. When it happens, a message shows on the dash that says press start button. No other codes or check engine light. Thankfully it has started every time, but this is obviously a serious safety concern. After the second time it happened, I had the dealer (woodhouse Buick GMC omaha) look at it on 9/14/2026, but they couldn't find anything since there were no codes. I'm not sure if it is an electrical issue or this is related but my audio will stop working at times as well. Nothing from the radio or any blinker sounds. Sometimes it's static with a high pitch noise. 2026 GMC sierra elevation 5. 3 ecotec3 v8 10 speed.
The contact owns a 2026 GMC Sierra 1500. The contact stated that while the vehicle was stopped, the gps was not operating as intended. The system failed to update after 15 minutes. The vehicle was difficult to start and had failed to start on another occasion. The vehicle was taken to the local dealer, and an update was forced and the battery was charged. The vehicle was scheduled for a fourth repair. The failure mileage was approximately 7,329.
While driving the truck it randomly shuts down, message on dash says shift to park to restart. No check engine light comes on or any other message. When it does this, the truck goes into park. It has been to the dealership 3 times and has not been fixed!.
Since I purchase this truck I've been having no audio twice a week. Dealer has no fix GMC knows they have issues and still they are selling this vehicles. Took a trip to [xxx] a storm was moving in and we had no audio to alert us I also believe with no audio we have no blinkers we almost cause an accident. Information redacted pursuant to the freedom of information act (foia), 5 u. S. C. 552(b)(6).
The vehicle lost power after sitting for a week. Start up with a jump, but the battery doesn't hold a charge after that.
The contact owns a 2026 GMC Sierra 1500. The contact stated that while driving approximately 60 mph, the transmission unexpectedly downshifted and the vehicle decelerated to 10 mph. No warning light was illuminated. The contact pulled over to the shoulder of the road, and the vehicle was towed to a local dealer. The vehicle remained with the dealer for additional diagnostic tests and unknown recurring failure codes. In addition, the contact stated that the failure worsened and occurred while his wife, sister-in-law, niece, and child were present inside the vehicle. The vehicle was not repaired. The manufacturer was made aware of the failure, and a case was filed. The failure mileage was approximately 7,500.
The contact owns a 2026 GMC Sierra 1500. The contact stated that while driving 35 mph, the vehicle stalled. Additionally, the wheels locked up, and transmission made a screeching sound. The contact was able to restart vehicle after approximately 5 minutes. The failure was recurrent. The vehicle was towed to the dealer, but the dealer was unable to duplicate the failure. The dealer replaced an unstated module that was damaged during the failure. The manufacturer was contacted by phone and was made aware of the failure. The failure mileage was approximately 6,000.
I was driving on 96 w. In slow traffic on the freeway when the vehicle put itself in neutral and shut off.
What component or system failed or malfunctioned, and is it available for inspection upon request? the truck has lost power unexpectedly while driving, and lately I've also noticed some lag when I accelerate. The truck is available to be inspected. How was your safety or the safety of others put at risk? the truck suddenly lost power while I was driving and told me to restart the vehicle. Losing power unexpectedly almost caused me to get stuck in an intersection and could have caused an accident in a busy shopping center. Has the problem been reproduced or confirmed by a dealer or independent service center? no. I took it to the GMC dealership after the second time it happened, but they couldn't get it to do it again and said there were no codes showing. They told me to bring it back if it happens a third time. Has the vehicle or component been inspected by the manufacturer, police, insurance representatives or others? yes. I took it to the GMC dealership to have it checked after the second power-loss issue happened. Were there any warning lamps, messages or other symptoms of the problem prior to the failure, and when did they first appear? when it lost power, the truck prompted me to restart the vehicle. I have also recently started noticing some lag when accelerating and starting the vehicle. There was no warning before it happened.
6 month old, 9,000 miles 2026 Sierra 1500 with duramax 3 liter suffered an engine control module failure 4 hours into a 12. 5 hour drive home from family vacation. First a transmission service warning flashed, then an emissions system failure with a forced speed reduction warning. This happened with two children and a dog in the vehicle. Onstar did diagnotics and said I had to see a dealer. Fortunately one was nearby and they determined the engine control module needed to be replaced--but I was 8. 5 hours' drive from home with kids and dog and would have had to stay for 2-4 days awaiting parts and repair. I traded the truck at the dealer for a new vehicle and drove that home. This was a major safety concern traveling with children and a dog on a nearly 100 degree day. And it was a brand new vehicle.
The contact owns a 2026 GMC Sierra 1500. The contact stated that while at a stop light, the engine shut off to save fuel, but after releasing the brake pedal, the engine failed to restart. The contact shifted to park, and the engine restarted. The contact stated that the failure had occurred on several occasions after the fuel saving feature was deactivated. Additionally, the contact stated that the failure had occurred while slowing down and driving over a railroad track and hauling a trailer. The vehicle was taken to the local dealer on several occasions, but the failure was not duplicated. The manufacturer was notified of the failure. The failure mileage was 4,300.
The contact owns a 2026 GMC Sierra 1500. The contact stated that intermittently there was no sound while the turn signals were activated, and the radio and incoming calls failed to be audible. The issue often lasted all day or for an hour or two before returning to normal. The contact associated the failure gm technical service bulletin: pit6406 (or pit6406f), but the dealer stated the vehicle was not included in the bulletin and refused further diagnostic tests. The vehicle was taken to a dealer to reprogram the audio control module (acm) because the software was outdated, despite the vehicle being brand new. The reprogramming was completed; however, the failure was not resolved. The manufacturer was notified of the issue. The failure mileage was 3,657.
No sound at different times. No way to reset issue. TSB issued may 14, 2026 for known issue. As of July 6, no estimate on repair. Blinkers make no sounds, onstar can call but you cannot hear them. In event of accident, no communication.
5/08/2026: I stopped outside my garage. I then placed the truck in park and exited the vehicle while running. I went inside my garage and several minutes later, heard a crash. The truck had driven forward while unattended, and crashed into the corner of my garage, causing damage to both the building and the truck. Truck indicated it was still in park upon reentry. 5/11/2026 in a separate incident 3 days later, while driving at approximately 50mph, truck engaged in an automatic braking event with no discernible cause. Simply applied what felt like 100% braking for a split second, then released. 5/12/2026: truck taken to GMC for investigation. No codes in any modules detected. 9/20/2026: vehicle reports transmission fault, states it should not be driven. 9/21/2026: towed to GMC dealer. Found codes p17a8 and p189d and diagnostic code 6906361, internal fault within gearshift control module. Requested GMC pay for damage resulting from collision, as clearly the unattended driving appeared related to gearshift control, but was refused. GMC stated that unattended driving was not possible and did not result from the detected failures.
I had this truck as brand new for approximately 24 hours when it had a major failure. It had 450 miles on it at time of purchase, but was sold as new. While driving at 45mph it had a check engine light, service power steering message, lost power steering, lane departure system failure, and reduced power amongst several other lights on the dash. I limped the truck into a gas station parking lot. After turning the truck off, it would not restart. I unhooked the battery for a minute and hooked it back up. The truck did restart with no messages or check engine light. I was able to safely get it to the dealership. As a result of this issue, I forced the dealership to cancel the trade.
We bought the vehicle on February 28th and on march10th my husband was driving on his way to work on the i95 highway and the engine shut down. My husband was in the middle of the highway with a speed limit of 65. Traffic was able to slow not to cause any more accidents however he had to be towed and gm replaced the engine. Because it had not been 30 days in the shop. Due to gm abiding by lemon laws we were not able to qualify for a buy back. We have been fighting with them ever since. I was able to get a reimbursement of my first car payment. However, my husband is a general contractor and is absolutely terrified to accept jobs far away because we don’t know when the truck engine might give up again. All of the charging ports stop working a couple of weeks ago, we had to take it in for repairs. This is a $78,000 vehicle with 4 miles on it when we purchased it. I don’t know what it is worth now because the engine was replaced with in 10days of purchasing it. I need help!!!!!!!!!!.
Vehicle stalled in busy intersection in mckinney texas , unable to start are shift into a neutral position on transmission to remove from extreme dangerous intersection, sheriff advised that road side assistance that was contacted is not going to be in time (90min)to keep from causing an ongoing traffic backup , sheriff dispatched their own towing service to resolve the situation from getting extremely dangerous . Vehicle and my wife was towed to mckinney Buick GMC dealership.
2026 Sierra 1500 at4 with 3. 0l duramax diesel. Three major issues. 1. 2960 miles, thrust bearing failure caused low oil pressure and internal damage. Vehicle needs complete engine replacement. The truck is still at the dealer with no eta on engine arrival and replacement. 2. Vehicle has severe electrical issues. Battery replaced on second day of ownership due to over charge and smoking. The truck would randomly lose the ability to produce sound through infotainment system on start. This includes warning sounds and audible turn signal sound. Dealer said it’s caused by faulty amp which was replaced. 3. The truck shut off (full system shutdown) and the transmission failed over to neutral while driving on the highway and failed to restart. Barely restarted on second attempt. Dealer has no idea why it is doing it. However the vehicle was throwing multiple code related to transmission module failure, brake module failure, transmission module failure, etc.
The telematics module for the onstar system continues to stop working, I have had this truck in a dealership service center multiple times for them to reset the system (instead of replacing the defective parts). Along with the infotainment system not working properly (cuts in and out, blinks on/off, delay in actions) doors unlock while driving, front/rear cameras come on when I stopping at an intersection, I have given them documentation of the diagnostic reports from dealerships.
The contact owns a 2026 GMC Sierra 1500. The contact stated that upon starting the vehicle and shifting into reverse(r), the vehicle failed to move while depressing the accelerator pedal. The contact felt a hesitation while depressing the brake and accelerator pedals, and the contact then attempted to restart the vehicle. The contact restarted the vehicl;e however, while attempting to accelerate, the brakes independently activated. Despite the repeated failure, the contact was able to pull into a gas station to restart the vehicle. The contact stated that after several attempts, the vehicle finally resumed normal operation, and the contact drove the vehicle to the residence. The next day, the contact test drove the vehicle, and the failure reoccurred while the contact was attempting to park the vehicle in a parking spot. The vehicle was taken to a dealer, where a diagnostic test produced 7 fault codes; however, the mechanic was unable to repair the vehicle. The manufacturer was notified of the failure, and the manufacturer stated that there was a communication disconnect between the contact and the dealer. A case was filed with the manufacturer. The vehicle was not repaired. The failure mileage was approximately 300.