2025 GMC SIERRA 1500 Electrical System Problems

Onstar telecommunications module failed within 5 months of ownership. GPS and in car navigation goes crazy showing incorrect position which is distracting on the infotainmet screen. Been almost 4 weeks with no estimate of part availability from GM.

My vehicle is equipped with multiple safety systems offered by general motors. Since purchasing my vehicle new, I have had a persistent and recurring issue related to the vehicle safety system, which is resulted in numerous collision detection and advanced cruise control service is not functioning as designed, creating safety issues for both myself and potentially other motorist on the road. Additionally, the parking sensors are not working as expected, presumably due to the same issue, which has resulted in numerous safety concerns, including the detection of vehicles or objects, which were not present, resulting in the systematic breaking function engaging posing a risk to myself and surrounding motorists. I initially reported the issue to GM on 2/20/2025, when the vehicle had 467 miles on the odometer. Since the issue initially began, I have returned to the GM service department at my local dealer a total of seven (7) times. The local service department has been in contact with GM corporate office related to the issue, however, they have been unable to rectify the issue and continue to send the vehicle back out on the road claiming the issue has been resolved only for it to recur shortly thereafter. I believe that GM providing the safety features in an inoperable state poses great risk to the general public, and the NHTSA should investigate this issue alongside the other active systemic issues GM is currently under investigation of. At this time, it is unknown what is the cause of the issue, multiple parts have been replaced, and the true cause of the issue has been undiagnosed.

The vehicle will loose all interior audio to include stereo, turn signals, and all other audio safety features for several hours at a time. GMC has done three repairs and still no resolution. Lack on audio impacts the safety of the vehicle. Has happened dozens of times and appears to be larger GM issue that is u resolved. Has occurred at least 20 times since I bought the vehicle 10 months ago.

--Radio power button inoperative --Radio channel change buttons, to left of steering wheel inoperative (everyday) --Radio volume inoperative -just stops working (sometimes) --Radio “HOME” button, left of radio power button inoperative --Driver door mirror wobbles when above 50 MPH (very distracting when driving) --Driver door hard to close and out of alignment --Dealership is selling the vehicles KNOWING some of the issues are present, but not advising the buyer. My safety is/was at risk due to having to move my hands off the steering wheel to touch the radio display to make any changes while driving. A certified GM service dept confirmed all my issues and could not repair. They quoted a PIT 6408. However, this particular PIT does not address my issues/concerns.

I purchased a 2025 GMC Denali a few months ago. At approximately 7,000 miles, the front brakes failed unexpectedly and were replaced by the dealership. However, by 14,000 miles, I began experiencing brake issues again. Before I could return the vehicle for service, I was driving on the turnpike when the engine suddenly seized without warning. This created an extremely dangerous situation—vehicles behind me nearly collided as I lost power and control. I managed to pull over safely, but the tow truck operator struggled to load the vehicle due to all four wheels locking up and the engine being completely seized. Once the vehicle was inspected at the dealership, I was informed that the engine had failed and would need to be replaced. I am aware of the recurring issues associated with the 6.2L GMC engines and related component failures, and I no longer feel safe driving this vehicle. Given the repeated mechanical failures and the serious safety risks involved, I am formally requesting that GMC initiate a buyback of this vehicle. I believe this situation qualifies under lemon law protections and warranty obligations, and I urge GMC to take immediate action to resolve this matter.

Power button (to turn on and off) to radios does not work, the "home" button to the left of the radio power button does not work.

I drove into my driveway put vehicle in park put my window shades up and vehicle went into drive and hit my garage.i had no warnings and this was caught on my ring camera.the ring camera caught my headlights lite up on outside edge and lights kept blinking off an on like there was some kind of glitch.my.the vehicle did not brake either.i saved the video. [XXX] INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

The cameras will work after the vehicle sits for awhile like after it cools down. But once driving or letting the vehicle run awhile the cameras shut down. I think the Video Processor Module gets hot and shuts down. General Motors is looking into this issue

On August 15th, 2025, I brought my new 2025 GMC Sierra 1500 Denali to Bill Cramer GM Dealership, 2251 W 23rd St, Panama City, FL 32405, due to a complete loss of audio in the cabin. This affected the turn signals, radio, and critical safety alerts, including collision warnings and seatbelt reminders. Given the vehicle's high cost and its status as a new premium model, this malfunction was both disappointing and alarming, particularly due to its implications for safety. This occurs about every third time I drive the vehicle. The dealership retained my vehicle for over a week to diagnose and address the issue. I received an email stating that the service was complete and the truck was ready for pickup. However, upon arrival, a service technician informed me that they could not identify the cause of the audio failure and, consequently, no repairs were made. I was told the dealership would continue consulting with General Motors' corporate engineers to determine the cause and solution.

The backup camera visibility at night is poor, making it very difficult to see behind the vehicle. This poses a potential safety hazard for pedestrians who may be in the path while reversing.

This is the second time in 2 days!! While driving ~35MPH the truck experienced a harsh transmission shift followed by a sudden loss of acceleration and entered shutdown mode to protect the engine. The steering became stiff, all dashboard warning lights illuminated, and a message appeared on the driver display indicating a transmission issue and advising to drive with caution. This created an extremely hazardous condition for me while driving on s busy stretch of road. I pulled onto the side of the road, came to a complete stop, shifted into park, and turned off the engine. Upon restarting the vehicle, the Check Engine Light remained on, and the transmission continued to shift abnormally at low speeds, including some noticeable shuddering. My GMC application recorded the issue and reminded me to schedule service.

While driving on the highway at 70 MPH, the truck experienced a harsh transmission shift followed by a sudden loss of acceleration and entered shutdown mode to protect the engine. The steering became stiff, all dashboard warning lights illuminated, and a message appeared on the driver display indicating a transmission issue and advising to drive with caution. The RPMs surged and the truck struggled to maintain a speed of 45 MPH while the remaining at 4000 RPM. This created an extremely hazardous situation for both me and my passenger. I safely pulled into the breakdown lane, came to a complete stop, shifted into park, and turned off the engine. Upon restarting the vehicle, the Check Engine Light remained on, and the transmission continued to shift abnormally at low speeds, including noticeable shuddering.

2025 GMC Sierra 1500 shifted from Park to Drive uncommanded, accelerated uphill, and crashed while idling, keyfob outside of vehicle, March 2025. ESIS couldn't replicate and falsely claimed I didn't put it in Drive, despite photos and no one inside.