2026 GMC Sierra 1500 electrical problems

Filed Nov 3, 2026 · Electrical · MN

My radio continues to suddenly reduce volume by approximately 70%. The volume will then come back for a second, then back down again. This can go one for several hours while on a trip, then suddenly back to normal. I have owned this truck for less than 3 months and have about 2500 miles on it. I was informed by a GM Service Technician that this has been an issue that GM is aware of but yet no remedy.

Filed Oct 23, 2026 · Electrical, Engine · NE

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

Filed Oct 22, 2026 · Electrical · 7,329 miles · NC

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.

Filed Oct 21, 2026 · Electrical, Engine · IL

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!

Filed Oct 13, 2026 · Electrical · TX

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)

Filed Oct 8, 2026 · Electrical, Engine · FL · crash

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.

Filed Oct 6, 2026 · Electrical, Engine · MD

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!!!!!!!!!!

Filed Sep 29, 2026 · Electrical · TX

The vehicle lost power after sitting for a week. start up with a jump, but the battery doesn't hold a charge after that.

Filed Sep 18, 2026 · Electrical, Engine · 4,300 miles · IL

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.

Filed Sep 16, 2026 · Electrical, Transmission · 3,900 miles · FL

The contact owns a 2026 GMC Sierra 1500. The contact stated that while hauling a trailer and making a left turn at 5 MPH, at a busy intersection, the message "Shift to Park" displayed, and the vehicle lost motive power. The vehicle was restarted. The contact stated that the failure was persistent. The local dealer was notified of the failure by phone. The vehicle was taken to the dealer, where it was diagnosed that the telematics module had failed and needed to be replaced. The vehicle was repaired. The failure mileage was approximately 3,900.