2023 GMC Sierra 1500

Vehicle will show lane keep assist system as active but provide no intervention and allow vehicle to travel into the next lane intermittently. System will also move itself to the next lane unexpectedly when near the lane markers of the original lane. Navigation system and radio will freeze, stop working all together, and at times fully reboot, randomly while in operation. While these issues are frequent, they are intermittent. No repair suggestions by dealer or manufacturer

Engine shut off on the interstate with no warning. Would not re-start. Forced to cross lanes on traffic with no engine power or power steering. Dealer stated it was the "Fuel Pump Control Module." Stated it was a common issue with parts most likely in stock, but it would be at least 6 weeks before they could even look at the vehicle.

This malfunction is ongoing and the dealership cannot fix the problem. The first time it happened in September 2025. I was driving down the road and the gauges started to go crazy. The screen on the dash said reduced acceleration. Then it said Service ESC. Then it said Service Traction Control. It would not let me go over 40 mph. I took it to the dealership and they told me I needed a valve body replacement. They installed the valve body and that did not fix the problem. It happened again and said reduced acceleration took over forcing me to pull over on the side of the road. The GMC dealership said to bring it in again but they could not reproduce the malfunction after driving for a week. It happens randomly. The third time this happened I was traveling up interstate 24 at about 70 mph. There were semi trucks around me when the malfunction happened and my acceleration and speed was reduced throwing the RPMs as high as they would go, and I was almost hit by a semi trying to move out of the way and onto the shoulder of the interstate I tried to accelerate to get out of the way of the semi truck but could not. I had to swerve over almost losing control of my truck. I informed the dealership that this had happened again and they asked me to bring it in. I did. They told me they were going to clean corrosion off of ground wires, and that should fix the problem. It did not. This keeps happening and I feel that the vehicle is not safe to drive. I do not know when it will happen again. I travel for a living and I feel the vehicle is unsafe to operate.

The OnStar vehicle locater, GPS maps, clock (auto update) are not responsive as of the 2nd week of December 2025. My truck cannot be located via OnStar, I cannot use the GPS Maps for directions, and the Clock reads 12 minutes fast when I put it into Auto Update mode. Reported to my GMC dealer (Elizabeth City GMC, Elizabeth City, NC 27909, and had in for service 3 times without correction of the issue! The dealership conducted a Software System Update which cost me $400.00, and still did not correct the issue. I spoke with OnStar three (3) times to try and correct issues but they did not resolve the problems either. OnStar stated it is a GMC issue............My last service at the Elizabeth City GMC dealer the Service Tech stated the OnStar Module is bad and requires replacement, and stated it will be an additional $550.00 +/-!!! Please advise and assist in further action I can take as this issue should be a Warranty issue and replaced by GMC and/or OnStar!!! Class Action Suit in line! Thank you.

The Telemetry/OnStar unit stopped working on my 2023 GMC Sierra 1500 Denali. This renders the OnStar unit unusable for both data and calling OnStar. In the event of an accident, the driver could not call OnStar for help and OnStar would not get an automatic notification that there had been a crash with the vehicle's location. The failure of the unit has also caused a code indicating Low Brake System Voltage. I know that is not the case in my vehicle at this time, but if the brake system does start to fail, there is no way to know if the code is real or just a result of the Telematics system failing. This failure occurred shortly after an Over-The-Air software update GMC sent out. I have seen numerous reports of people with the exact same year and model having the same issue. The unit worked fine for 2.5 years and after the software update, it was bricked. GM wants in the neighborhood of $1,000 to replace and install the unit but they are on backorder with ETA's 3 or 4 months out. They are also coded with the VIN so there is no other option than to go to the dealership for repair. The part cannot be ordered from an aftermarket manufacturer or from GM's official parts website, local dealership only. In order to get this important safety feature working again, the only option is to go have it fixed at the dealership, which charges $200/hr in labor on top of the $500 part needed. The 3-4 month backorder should be enough evidence that GMC has had a widespread failure of these units. GMC basically broke the Telemetry/Onstar units with a software update and wants it's customers to pay for their mistake. If this is not considered an important enough of a safety feature for NHTSA to do an investigation on, this matter should be investigated as an illegal business practice with the FTC or Department of Justice. GM has effectively created a problem (through the software update) that only they can fix and then charging customers whose warranty has expired.

OTA update GM N25-250380 caused significant problems. Blinker tone and other safety tones are erratic. Infotainment system is erratic. Constant reboots while driving causing distractions. Camera screens will freeze on screen while driving down interstate. It may be affecting other systems as well since everything is erratic and buggy now.

Truck will down shift and transmission will slam, super hard. feels like i hit something. almost causing accident. dealership refuses to service my truck or even take a look at the transmission because "its not broken yet" in their words " it needs to fail before they can service it or even look at it, because they wont get paid." I have expressed my concerns about this safety issue and at this point they are being negligent. My truck is a 2023 gmc sierra 1500 with 3.0 duramax . still under warranty with only 35k miles.

The vehicle has suffered repeated systemic electrical failures all while being under 8,000 miles. What component/system failed? Power distribution/fuse block, starter, fuel pump control module, horn circuit, body control module, instrument cluster, and charging system. Error codes documented include P0627 (Fuel Pump Control Circuit), U0100 (Lost Comm ECM/PCM), B1325 (Control Module Power Low), U0140 (Lost Comm BCM), and B1000 (ECM fault). All repairs are documented by the dealer, and the truck remains available for inspection. How was safety at risk? The truck lost propulsion at speed, emitted smoke from the engine bay, and became disabled in traffic, placing my family, including my toddler, in immediate danger of collision and fire. Electrical defects also disabled horn and instrument cluster, removing critical warning and signaling functions. These electrical issues have been ongoing for months and GM refuses to replace and can't seem to fix it. Has it been confirmed? Yes. Each failure was diagnosed and confirmed by an authorized GM dealer. Components replaced include fuse block, starter, fuel system computer, horn assembly, and cluster. Despite repairs, issues recur. Inspected by others? GM corporate case managers are aware and have acknowledged defects, though they have refused to issue written determinations. Insurance has not yet been involved, but records are available. The dealer has attempted to repaid more than 4 times with no success. Warning lamps/messages? Yes. Prior to and during failures, vehicle displayed repeated “Service Electrical System,” “Low Voltage,” and communication fault codes. Cluster intermittently blacked out. Smoke in engine bay indicated immediate fire hazard. Cumulative out-of-service days exceeding 20. The failures pose unacceptable risk of fire, sudden propulsion loss, and loss of critical safety functions. I have ALL calls with GM recorded and transcribed as I am in SC (single party recording state) and can provide those.

The entire instrument panel is blacked out. I can not see the speed, how much fuel and no waring lights etc. The screen flashes between black and dark blue and there is a repetative "ding" that I have no idea what is caused from since I can not see any warning lights, etc.This puts me and others at risk due to not being able to see any functions for operation of the vehicle, the speed or any indicator lights of vehicle issues. The dealer has seen the truck, and informed me that this is a known problem and they would have to order parts. According to the service department, parts for replacement will be covered under warranty/recall and they have been on order. It has been 3 weeks and they have no knowledge of when the parts will be in to make repair. There was no warning on this problem, the panel just went out.