Electrical System Problems of GMC Sierra 1500 - part 2

The morning of December 12th, 2025 I used my vehicle to transport my daughter approximately 5 miles round trip from our home to drop her off at daycare and then I returned home. I used my front and rear defrost elements to expedite removal of heavy condensation which had formed on all windows overnight. This was approximately 7 am. I parked my truck in the driveway and went inside until approximately 11:45 am when I went to leave in my truck and noticed the rear sliding window had shattered. The window shattered and distributed tempered glass fragments all over the inside of the cab. Only approximately 10% of the window remained intact. I then reviewed the security camera footage from my driveway and discovered that the window failed entirely on its own with nothing hitting/striking/touching the window, nor any humans or animals in the vicinity. I attempted to take the vehicle to a GMC service department this morning (Dec 13) but due to their demand to keep the vehicle for 2-3 days to investigate yet unable to provide a loaner vehicle, I was unable to leave the vehicle in their possession and returned home. I plan to continue to contact GMC dealership service departments in hope I can find one which can provide a loaner vehicle, as I will need transportation to and from work in the coming days. I do have video footage of the incident although I am unable to add it below.

See all problems of the 2020 GMC Sierra 1500 🔎.

Heated steering wheel reaches temps of 137 - 143 degrees. Should have the ability for the owner to select a lower temperature setting the same as the heated seats.

See all problems of the 2025 GMC Sierra 1500 🔎.

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.

See all problems of the 2023 GMC Sierra 1500 🔎.

1. )when driving the vehicle it will randomly shutoff while driving with loss of brakes and steering until it will randomly turn back on. The vehicle experiences intermittent electronic and drivability malfunctions. The issue appears to involve one or more vehicle control modules and/or electronic systems. At times, warning lights and system messages appear, and vehicle performance is affected. The vehicle is available for inspection upon request. 2. )these failures create a serious safety risk because they occur without warning while driving. The vehicle may lose normal functionality, display multiple warnings, or behave unpredictably. If this occurs in traffic, at speed, or while maneuvering, it could increase the risk of a crash or leave the vehicle stranded in an unsafe location. Furthermore on 3 separate circumstances I came close to crashing the vehicle putting at risk lives in the vehicle and outside. 3. )the problem is intermittent and has been difficult to reproduce on demand. I have taken the truck to the dealership multiple times. The dealership has stated that because the issue is not actively occurring when they have the vehicle, they have been unable to duplicate the concern and have instructed me to continue driving it until the issue happens again. Despite this, the problem continues to return during normal use. 4. )the vehicle has been inspected by the authorized dealership on multiple occasions. To my knowledge, it has not been inspected directly by the manufacturer, police, or insurance representatives. 5. )intermittent warning lights and system messages appear, including at times a check engine light and other alerts. These warnings may appear suddenly as the truck shuts off and then disappear after the vehicle is turned off and restarted. Another thing to point out is that the audio and turn signal chime cut off randomly. The issue first began while the vehicle was already in normal use and has continued to reoccur since.

See all problems of the 2022 GMC Sierra 1500 🔎.

Tailgate unlatched by itself, first time I was connected to a trailer and it damaged the tailgate. Multiple (4+) times afterwards while being parked in garage tailgate opens by itself all during the same day could not get this to stop. Called dealership today for appointment where they could get me in the shop in the middle of the week, but they told me that this issue is known but not covered under my VIN.

Every winter when the temps dip into single digits something on the truck freezes and causes a major malfunction. This winter (2025) is the second time I’ve had a problem with the truck freezing up and leaving me in “limp mode”. Last year the same thing happened. The def sensors freeze up and the heater shorts out leaving me stranded in my $70,000 truck. I now have 34miles remaining until my truck is limited to 55mph. This is a serious problem.

See all problems of the 2024 GMC Sierra 1500 🔎.

This happens many times, at random intervals, and sometimes it does not happen at all, but I would say about 33% of the time, it happens. When you put the vehicle into reverse, the side mirrors will lower slightly, so that its easy to see the ground, or parking lines, etc. When you then go back to park or forward gear, the mirrors are supposed to go back to the position they were earlier. The original starting point. But that's the problem, many times, they do not go back to the starting position and you must then push the preset buttons to make them go back to your desired view angle.

The contact owns a 2016 GMC Sierra 1500. The contact stated that while idling in the drive-through at a pharmacy, the contact noticed smoke coming from the rear window, and the rear window shattered. The contact stated that the defroster was activated at the time of the failure. There was no injury sustained. The contact deactivated the defroster and drove to the residence, where the contact disconnected the defroster fuse. The contact related the failure to customer satisfaction program number: n192265660 (rear window defroster thermal events). The vehicle was not diagnosed or repaired by an independent mechanic. The manufacturer was notified of the failure and referred the contact to the NHTSA hotline to report the failure. The failure mileage was approximately 139,250.

See all problems of the 2016 GMC Sierra 1500 🔎.

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.

The contact owns a 2016 GMC Sierra 1500. The contact stated that her husband remote started the vehicle. The contact stated that when the vehicle was started, the defrosters automatically activated. The vehicle warmed up for approximately 2 to 3 minutes. The contact stated that while leaving the driveway, her husband stopped the vehicle to assist with moving a lawn mower. Upon returning to the vehicle and looking through the glass her husband observed that there was smoke coming from the rear glass. The contact stated that her husband unlocked the rear doors and released the folding rear seat and saw that the defroster unit was on fire and smoking. The contact stated that her husband turned the vehicle off and the flames were self-extinguished; however, approximately 45-seconds later the driver’s side rear panel window shattered. The vehicle was not taken to a local dealer or independent mechanic to be diagnosed or repaired. The contact researched online and related the failure to customer satisfaction program number: n192265660 - rear window defroster thermal events (electrical system, visibility). The manufacturer was informed of the failure and referred the contact to the NHTSA hotline to report the failure. The failure mileage was approximately 89,000.

Experience a automatic ota update to the info system on my 2021 GMC sierra(I did not iniciate) which burnt out the radio module which controls the info system. I am being charged $1,300+ for repair due to vehicle being out of warranty(52,000 miles) and no recall on this vehicle model for this issue. GMC does have a recall for this exact issue on the 2021 GMC tahoe models, but not the GMC sierra. If the GMC utilizes the same componets for both models of vehicle how doe the recall#n202319250 not cover the exact same issue on both models?.

See all problems of the 2021 GMC Sierra 1500 🔎.

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.

The contact owns a 2025 GMC Sierra 1500. The contact stated that while stopped at a traffic light, the gear shifter was shifted to park(p) and the vehicle stalled. The message "start engine" was displayed. The vehicle was restarted, and the auto start/stop feature was disabled by pressing the "a" inside an orange circle. The contact stated that on another occasion while reversing into the driveway, the vehicle stalled. The message "start engine" was displayed on the screen. The dealer was contacted; however, the vehicle was not taken to the dealer or an independent mechanic. The vehicle was not repaired and the failure persisted. The manufacturer was not notified of the failure. The failure mileage was approximately 16,000.

Muti pro tailgate has electric issues due to moisture. Tailgate will open up driving down the road.

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.

Telematics module failed directly after update, vehicle is outside of warranty (by mileage) but only 3 years old. No gps, onstar, and several other features that rely on this system to operate. Several dealers would not even look at it when calling for appointment, one dealer stated that the part was on back order for up to 2 years and did not want to waste the time to look at it. Upon research, this appears to be a very common problem on all gm models with similar outcome.

After pulling my 2024 GMC Sierra 1500 slt into a parking space at a local store, I shut off the engine. I observed the lighted ignition switch and the dash icons were illuminated even though the engine was completely off. Having had my foot on the brake at the time I decided to test the ignition switch to determine why it was lit while the engine was off. When I pressed the start button there was a loud, whining starter like sound, grinding like metal on metal. The noise was so alarming that I immediately took my hand off the ignition. The engine was still off. After waiting a significant amount of time I tried to restart the engine. Exactly the same thing occurred. On the final attempt to start the engine, 15-20 minutes later, it started and ran quietly like nothing had ever happened. On returning to the vehicle my wife asked what all the loud grinding noise was about. She had heard it while she was inside the store. I advised her it was our truck! the incident was shocking to us both and because of its bizarre nature I was afraid to drive the vehicle back home. As I already had an appointment on November 6 at deluz chevy for another incident, I called them on November 3 to add this incident to the existing appointment. This incident was added to the November 6 appointment. Unfortunately the service department did not assess the previous incident and only addressed this incident.

The contact owns a 2019 GMC Sierra 1500. The contact stated that while driving at 25 mph and making a turn, the vehicle lost motive power. There were several unknown warning lights illuminated after the failure. Upon investigation, the failure was related to NHTSA campaign number: 25v274000 (engine and engine cooling). The vehicle was towed to an independent mechanic, where it was diagnosed with lifter failure and camshaft damage. The vehicle was repaired. The local dealer was not contacted. The manufacturer was contacted and opened a case, and referred the contact to the local dealer for assistance. The failure mileage was approximately 86,960.

See all problems of the 2019 GMC Sierra 1500 🔎.

Following the remedy of the engine recall in 2025, the truck started having intermittent electrical issues (I. E. Warning lights on dash turn on/off: service 4wd, loss traction control, etc) come one while the truck is being driven. If the truck is turned off while the dash warning lights are on, it will not start for about 24 hours. If the warning lights are ignored, eventually they will go off on their own. Additionally, the truck is having "no-start" problems (randomly the truck does not start, then after a few days it starts). A new development, when backing up there is a scraping/squealing sound (possibly universal joint). Truck has been back to the dealership that replaced the engine block for the recall and they have failed to identify any issues as these problems are intermittent. Engine recall replacement invoice (attached).

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.

Complete engine failure. I was driving approximately 55 miles an hour, then all of a sudden the cruise control automatically shut off and a series of alarms are triggered. When pressing the accelerator pedal, the engine vibrated excessively in cleary indicated catastrophic engine failure. I was lucky enough to make it to the nearby dealer who confirmed a complete engine failure. I ended up buying a new vehicle that day to avoid being stranded.

This truck needs 2500. 00 in work to replace electrical harness after months of problems and evaporating leaks.

Coolant control valve and engine cooling fan.

I am an active u. S. Air force member. My 2021 GMC Sierra 1500 failed gm recall n252494003 on sept 29, 2025 (l87 engine loss of propulsion). Gm states this defect can cause sudden engine failure and loss of propulsion, increasing crash risk. Despite the confirmed failure, ocean Cadillac (miami, FL) told me to keep driving the unsafe vehicle and refused all courtesy transportation. The service manager admitted in writing that the engine failed, the defect can cause loss of propulsion, and the replacement engine is delayed under gm national control for up to 3 months — yet they still denied me a loaner or rental. His statements contradict the gm documents he attached: • gm bulletin dcs7222 says courtesy transportation can be provided during l87 recall downtime and dealers must consider loaners/rentals. • gm faq n252494002 says courtesy transportation is available for this recall. • gm faq lists recall symptoms (check engine light, hesitation, high rpm, reduced power) — not battery drain. • gm states: “if the engine fails, the vehicle will lose propulsion. ” ocean Cadillac ignored these rules and put me back on the road in a known unsafe vehicle. As an american manufacturer, gm has a responsibility to protect american drivers. Their failure to follow recall procedures placed me, my family, and other motorists at risk. I request NHTSA investigate whether gm/ocean Cadillac are complying with recall safety requirements and whether customers are being told to drive unsafe vehicles after confirmed failures.

The contact owns a 2022 GMC Sierra 1500. The contact stated that while driving at various speeds, the tailgate opened unintendedly. The contact stated that the failure occurred while the vehicle was idling or while parked. The vehicle was taken to the dealer, where it was diagnosed, and the contact was informed that the failure was caused by a corroded wire. The dealer determined that the wire and the tailgate switch needed to be replaced. The dealer confirmed that the vehicle was not included in a recall or covered under warranty. The vehicle was not repaired but was scheduled for repair. The manufacturer was not made aware of the failure. The failure mileage was approximately 65,000. The VIN was not available.

Every time I pull the truck into my garage or a parking stall at low speeds while using the front park sensor it will shut off with the automatic start stop while still in motion. Then you have to let off the brake pedal for it to start and sometimes the vehicle will search forward.

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.

Truck went in service 9/17/2025 because the wheels locked up while driving. Transmission was replaced. Picked up truck and 2 hours later the truck shut off while driving and was started back up and was limp mode. Was told wire chaffing and they taped and rerouted wires. Picked truck back up and next day it did the same thing. Took back to the dealer and they said wires again. They taped wires back up and we picked up the truck. We had it 7 days and while driving down the expressway the whole truck shut off and would not start up again. Clearly that is a safety issue. After sitting on the side of the expressway for 10 minutes it started up again and was in limp mode and taken to the dealer again. I don’t know what has been done to it yet as they are not great at communication but they have had our truck for 4 months minus the 7 days we had it before it had to go back to the dealer.

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.

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.

I am experiencing a recurring issue with my 2021 GMC sierra where the dashboard displays a “shift to park” warning even though the vehicle is already in park. This typically occurs when I attempt to shut off the vehicle. The doors unlock as expected, confirming the truck is in park, but the warning prevents me from turning off the ignition immediately. After a few seconds, the warning usually disappears, allowing me to shut off the truck. This issue is more frequent in cold weather, suggesting a temperature-sensitive electrical or mechanical fault. Based on research and community reports, this appears to be a known issue across multiple gm vehicles, often linked to a faulty micro switch or wiring harness in the shifter assembly. I am concerned about the safety implications, especially if the vehicle fails to shut off properly or if the issue worsens over time. Gm has not issued a recall for this problem, and I believe it warrants further investigation due to its widespread nature and potential risk.

I purchased my 2024 GMC Sierra 1500 on July 4, 2024. Shortly after purchase, the vehicle began experiencing recurring electrical and electronic malfunctions affecting multiple safety and driver-assistance systems. These issues include power mirrors not consistently folding when the vehicle is locked, the digital speed (mph) intermittently not displaying on the dashboard, driver seat memory not always setting upon entry, and blind spot warning indicators activating while driving when no vehicles or objects are present. More critically, the rear parking assist sensors do not function consistently and often fail to alert before contact with an object. I have backed into objects on multiple occasions before the sensors activated or without any warning, creating a safety risk while reversing. I first brought the vehicle to the dealership on January 13, 2025 for these issues, but they were not resolved. I purchased two GMC-branded trailer cameras in December 2024 that are advertised as compatible with this vehicle. On September 1, 2025, I returned to the dealership when the “invisible trailer” feature became inoperable. The trailer camera system frequently shows a black screen, cuts out intermittently, or fails to display an image. I returned again on September 11, 2025 due to continued failure of the invisible trailer feature and rear parking assist. The dealership kept my vehicle until December 2, 2025 (approximately one month), but the issues remain unresolved. I am scheduled to return again in January. These failures reduce rear visibility and compromise multiple safety systems. Despite repeated dealership repair attempts and extended service time, the problems persist, suggesting a defect involving the vehicle’s electrical system, sensors, software, or camera modules. I have photo and video documentation of these failures.

The contact owns a 2022 GMC Sierra 1500. The contact stated that while driving at 60 mph hauling a trailer going downhill, the engine seized. The vehicle was difficult to control. The message to “shift to neutral and restart" was displayed. There were no warning lights illuminated. The driver attempted to restart the vehicle. The contact stated that the running boards were stuck outwards. The contact received notification of NHTSA campaign number: 25v274000 (engine and engine cooling). The vehicle was towed to the local dealer, where the engine was replaced after two months. The dealer informed the contact that the battery was completely drained. The manufacturer was contacted, but no assistance was provided. The failure mileage was approximately 67,500.

Vehicle (2019 GMC sierra slt x31!crew cab 6. 2 l gas engine) stopped running while driving down the road (Wednesday 9/3/2025). Tried to start truck - would crank over quickly but failed to start ( crank no start with no check engine light. ) tried several times same result. Started after about 5-10 minutes and was displaying low fuel indicator even though we knew it had approximately 1/2 tank. We immediately put gas in it and it took approximately 1/2 tank to fill. Still no check engine light and confirmed no stored codes via onstar report. Drove the truck around for may 1hr and check engine light came on but was still running and did not stop running like it did earlier. On star reported ecm system code p129f ( fuel pump or fuel pump power control module). Long story short, put truck in independent repair shop I use. They diagnosed it was a defective fuel pump located in fuel tank. They told me gm technical support recommended to replace the fuel pump and fuel pump power and control module at a cost of ~$1325. 00. It is my opinion this is a safety hazard and very similar if not exactly the same failure symptoms / modes as others have already reported. I requested to keep the failed parts and still have them in my possession. Please review and let me know if you need or want additional information . Best regards, bruce rivera 512-924-9839 riveratb176@gmail. Com.

--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.