Electrical System Problems of GMC Sierra 1500 - part 2

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.

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.

Truck completely shuts off at any speed going down the highway. Complete loss of power. Have to coast to side of road and restart vehicle.

See all problems of the 2014 GMC Sierra 1500 🔎.

Truck randomly shuts off and steering wheel locks up going down the road.

Tailgate opened several times without being prompted. Once while driving, two times while in park.

See all problems of the 2023 GMC Sierra 1500 🔎.

Per my dealership, there is chaffing in the main wiring harness of the vehicle and the entire harness needs to be replaced. On recall n222391510, for sierra's of the same year, the harness had to be replaced as well.

Subject: urgent vehicle safety complaint – 2019 GMC sierra denali escalating mechanical and electrical failures — many beginning before 100,000 miles, and continuing as of today, at approximately 110,000 miles. These issues have made the vehicle unreliable and unsafe to drive. Since purchasing the vehicle, I have had it serviced regularly and reported that it was driving rough, jerking into gear, and showing early signs of engine and transmission problems. These issues were noted during multiple multipoint inspection services, yet no lasting solutions were provided. Major issues have included: •engine performance failures •fuel injector malfunction •serpentine belt and idler pulley damage •a/c compressor belt failure •power steering malfunctions •vehicle stalling at traffic lights •loss of power on major highways •rear window water leaks •significant and ongoing electrical system problems •shaking when brakes applied after having brakes and rotors replace in March •screen monitor going out after paying over $ 900 dollars for updated software and repairs to the electronic component that cost over $2500. Despite continued maintenance, on Thursday, July 3, 2025, my truck began losing power and smoking heavily while driving on a busy highway in georgia. My grandchild, who was riding with me, yelled, “grandma, it’s smoking — please get out!” as we pulled off the road in fear of a fire. This terrifying incident left us stranded and emphasized just how dangerous this vehicle has become. I filed a formal complaint with the GMC corporate office, but no support provided or an investigation. Over the past six months, I have spent more than $5,000 trying to keep this vehicle operational. So many critical systems have failed, despite consistent maintenance, raises serious concerns. Finally, the fuel injector repaired 3 days later a message on dashboard displaying service tire monitor system and steering wheel shaking when brakes are applied.

See all problems of the 2019 GMC Sierra 1500 🔎.

I've had the vehicle service twice for the same incident power steering shut off in the middle of drive vehicle shuts down almost smashed into a freeway wall. This has been to the dealership numerous times to fix it and they have not. We are in the tens of thousands of dollars in repair and still nothing is fixed I've had this vehicle for 5 years it's been in the shop for at least 3 I bought it with 30000 miles it only has 61000 on it right now the last repair lasted 10000 miles this repair only lasted 4000 I almost died and was left is petrified.

See all problems of the 2018 GMC Sierra 1500 🔎.

Intermittently there isn't any sound from informational center speakers, this includes not sound of the turn signal indicators working. No sound from any vehicle component, vehicle has the current software release from gm. The only way I've found to get sound again is to leave the vehicle set not running for some period of time, short off then back on doesn't seem to clear the issue. I've check with the dealer and from what I understand this is a known issue with 2024 & 2025 gm informational centers.

See all problems of the 2024 GMC Sierra 1500 🔎.

Power steering works sometimes and then stops trailer break system issues.

See all problems of the 2020 GMC Sierra 1500 🔎.

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.

My 2019 GMC sierra denali shut off suddenly while I was stopped in traffic. The engine died, the steering wheel locked, and the dashboard displayed warning messages including “esc,” “power,” and another I didn’t catch. The truck would not restart despite attempts. The check engine light is now on. This happened without warning, and I had no prior mechanical issues. The vehicle is well maintained, garage-kept, and recently received a full service including oil change, brake work, and 75k-mile recommended service. I fear this is related to a known issue affecting other GMC engines under investigation for sudden power loss.

1. The vehicle’s emissions system is malfunctioning, specifically the ecm (engine control module) related to the exhaust emissions system. The diagnostic trouble code is p2c7a, indicating the system is not performing as expected. Key components such as the nox catalytic converters and diesel particulate filter have been repeatedly replaced, but the issue persists. The vehicle and all replaced components are available for inspection upon request. 2. The malfunctioning emissions system has led to an exhaust leak that allowed exhaust gases to enter the vehicle’s cab. This creates a hazardous environment for both the driver and passengers, exposing them to harmful exhaust fumes. In addition to reduced engine performance, poorer fuel economy, and emissions non-compliance, this exhaust leak poses a serious safety risk by compromising the air quality inside the vehicle. Prolonged operation under these conditions could lead to adverse health effects and further mechanical failures that impact vehicle safety. 3. Yes. The dealership has diagnosed the problem multiple times. The emissions components have been replaced under warranty on two separate occasions. The dealer attributed the fault to fuel quality; however, fuel distributor debunked these claims. 4. The vehicle has been inspected extensively by the dealership with invoiced repair work replacing key emissions control components. 5. The check engine light and service engine soon (ses) light have been illuminated with the diagnostic code p2c7a since the initial identification of the problem which started 3jun24.

Subject: urgent safety complaint dear GMC customer service, I hope this message nds you well. I am formally reporting a serious safety issue with my GMC vehicle. The car has experienced multiple dangerous incidents due to likely electrical or software faults, losing power suddenly on two occasions while driving. This is especially concerning given the low mileage of 20,000 km and that the vehicle is still under warranty. Vehicle information: • model: GMC sierra sle, 2024 • VIN: [xxx] • current mileage: 20,000 km description of the problem & history: 1. First incident (at 3,000 km): o the vehicle completely shut down due to an electrical or system software issue while driving. O the vehicle was towed to the dealer and held for over two weeks for repairs. 2. Second incident (recently): o the vehicle again lost functionality; the gear was stuck in 1st gear, and I was unable to manually shift. O this occurred while driving, creating another unsafe situation. O the vehicle was again taken to the dealer for repair, and to date, I have not been informed of the root cause. Actions taken: the vehicle was brought to sarhan, uae (sharjah), al ghandi auto after the rst incident. Despite inspections and repair attempts, the issue has recurred, indicating it was not resolved. And I am prepared to provide photographic or video evidence if necessary. Additional context: • the vehicle is less than one year old and has been regularly serviced on time at authorized centers. The recurring issues strongly indicate an underlying reliability or manufacturing defect. Due to the severity and recurrence of these failures, I refuse any further repair attempts. I formally request either a full refund or a replacement vehicle, as this is unacceptable for a new car. Please acknowledge receipt of this complaint promptly and advise on the next steps for a swift resolution. Sincerely, [xxx] phone: [xxx] email: [xxx] location: sharjah, uae information redacted pursuant to the freedom of information act (foia), 5 u. S. C. 552(b)(6).

Subject: urgent safety complaint dear GMC customer service, I hope this message finds you well. I am formally reporting a serious safety issue with my GMC vehicle. The car has experienced multiple dangerous incidents due to likely electrical or software faults, losing power suddenly on two occasions while driving. This is especially concerning given the low mileage of 20,000 km and that the vehicle is still under warranty. Vehicle information: •model: GMC sierra sle, 2024 •VIN: [xxx] •current mileage: 20,000 km description of the problem & history: 1. First incident (at 3,000 km): othe vehicle completely shut down due to an electrical or system software issue while driving. Othe vehicle was towed to the dealer and held for over two weeks for repairs. 2. Second incident (recently): othe vehicle again lost functionality; the gear was stuck in 1st gear, and I was unable to manually shift. Othis occurred while driving, creating another unsafe situation. Othe vehicle was again taken to the dealer for repair, and to date, I have not been informed of the root cause. Actions taken: the vehicle was brought to sarhan, uae (sharjah), al ghandi auto after the first incident. Despite inspections and repair attempts, the issue has recurred, indicating it was not resolved. And I am prepared to provide photographic or video evidence if necessary. Additional context: •the vehicle is less than one year old and has been regularly serviced on time at authorized centers. The recurring issues strongly indicate an underlying reliability or manufacturing defect. Due to the severity and recurrence of these failures, I refuse any further repair attempts. I formally request either a full refund or a replacement vehicle, as this is unacceptable for a new car. Please acknowledge receipt of this complaint promptly and advise on the next steps for a swift resolution. Sincerely, [xxx] phone: [xxx] email: [xxx] location: [xxx] information redacted pursuant to the freedom of information act (foia), 5 u. S. C. 552(b)(6).

Loss of power steering. Loss of engine propulsion at high rates of speed. Engine would not start.

During a turn in the parking lot my vehicle would not allow me to turn something with traction control came up on the screen. The past few days the car got stuck at 0 rpms while driving and did not feel I had adequate power and other times has stalled.

The contact owns a 2024 GMC Sierra 1500. The contact stated that while operating the vehicle, the windshield washer fluid activated unintendedly and sprayed over the front windshield, causing a visibility hazard for the driver. The vehicle was taken to the local dealer who repaired a loosened electrical wire, and the vehicle was repaired. Additionally, the radio cluster unintendedly deactivated, and the onstar service became unavailable. The vehicle was taken to the local dealer who replaced the radio cluster, but the failure persisted. The manufacturer was not yet contacted regarding the failure. The failure mileage was 3,000.

Tailgate automatically opens while driving or in park tailgate fell down on its own and hit garage door causing a scratch scrape of paint vehicle only has 46000 miles this part should not have gone bad already and why was this year not on the recall should not have to pay for part and labor on a 3 yr old truck bad business. . . Onstar module went bad GMC truck only 3 yrs old should not have to pay for part and labor and installation on a new module this failure should be covered by gm as it there fualty part on a new vehicle bad business.

See all problems of the 2022 GMC Sierra 1500 🔎.

The vehicle consistently shuts off unexpectedly when trying to park or slow down, making it difficult to steer or control. The electric power steering stops working, especially when turning at low speeds.

See all problems of the 2017 GMC Sierra 1500 🔎.

Subject: urgent safety concern – widespread failure and nationwide backorder of onstar module (gm part no. 86803964) dear NHTSA, I am writing to formally raise a serious concern regarding a widespread and well-documented failure of the onstar module (gm part no. 86803964) in 2023 GMC sierra vehicles and potentially other gm models. I own a 2023 GMC sierra equipped with this module, which has failed, rendering my vehicle’s entire instrument cluster completely inoperative. All screens, including the digital gauges and essential driver information displays, are blacked out, leaving the vehicle in an unsafe and non-drivable condition. After contacting numerous gm dealerships across the country, I have discovered that this part is on national backorder, with over 4,000 units reportedly pending. I have also learned that the part number has been superseded multiple times, suggesting an ongoing and unresolved issue. To make matters worse, specmo is reported to be the sole refurbisher and distributor of replacement modules, further limiting availability and delaying resolution. This issue directly affects vehicle operability and driver safety. The inability to access critical information such as speed, fuel level, warning indicators, and system diagnostics significantly increases the risk of accidents and vehicle malfunctions. Given the scale of this issue and its impact on public safety, I urge general motors, relevant regulatory bodies, and consumer safety agencies to investigate this matter thoroughly. A recall, expedited solution, or broader communication to affected customers appears necessary at this stage.

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.

While attempting to park my 2016 GMC Sierra 1500 at less than 5 mph, the steering wheel suddenly jerked on its own, the stabilitrak warning light turned on, the dashboard flickered, and the entire electrical system briefly shut off. The anti-theft light also came on during this incident. After restarting the vehicle, it temporarily returned to normal, but this kind of malfunction is extremely dangerous — especially if it were to happen while driving. It’s very upsetting that gm has not included the 2016 model year in the recall for this exact issue, even though many owners are clearly experiencing the same symptoms as the 2014 and 2015 trucks that were recalled. This needs to be addressed for safety and fairness.

See all problems of the 2016 GMC Sierra 1500 🔎.

Engine has had recall and still no remedy for it. Paint is chipping off and back locks stopped workingp.

The dealer is telling me there is a faulty engine coolant, flow control valve on this vehicle and multiple other people are having the same issue. The part is on backorder and takes months to arrive. They are telling me I can drive the vehicle, but it becomes a safety issue because the engine thinks it is overheating and goes into reduced acceleration mode, which can impact safely driving the vehicle. Pulling out in traffic and not being able to accelerate can be extremely dangerous.

Gm has has a known issue with a switch/sensor placed at the base of the shifter that causes the “shift to park” error message that prevents the electrical system from shutting down when the vehicle is physically in park and the engine is turned off, in fact, gm has issued a recall for several different models in which a “shift to park” error message is displayed because of the poor design; however, they continue to see the same issue occur but claim it is not a warranty issue (unless it occurs within 3 year/36,000 mile time frame. This is not an issue that can be caused by owner misuse, and I believe that gm should be held liable for repairs given that the issue is, and has been, known for several years now.

See all problems of the 2021 GMC Sierra 1500 🔎.

I’m contacting you regarding my 2019 GMC Sierra 1500 with the 5. 3l v8 engine. The vehicle is currently experiencing a cylinder 8 misfire (code p0308), accompanied by engine backfiring, ticking noise, and exhaust fumes inside the cabin. Additionally, the esc (electronic stability control) warning light is on, and performance is noticeably affected. To date, I have: •replaced all spark plugs and fuel injectors •verified proper ignition coil function •had an oil change on September 23, 2024, during which I reported early concerns about engine performance (shortly after the powertrain warranty expired) •had a transmission flush on March 17, 2025, in an attempt to resolve continued drivability issues despite these efforts, the issue persists. Given the known issues with afm lifters and camshaft wear on this engine, I suspect a mechanical failure related to that system.

Woke up one morning and the entire back seat, entire truck flooring was soaking wet. Got it to gerber collision in el reno, oklahoma. They said that the back window had a crack in it. My insurance said it is a mechanical issue on the sliding back glass and they do not cover such issue. Also want to turn in that the transmission in this truck had to be replaced two week prior to this incident. The truck only had 118,000 miles on it. Safe to say that this 10 point GMC diesel truck is a nightmare and the entire truck is a hazard. They need to take these truck off the market.

While exiting the highway and transitioning into a turn lane, my 2024 GMC sierra at4 (with 12,887 miles) suddenly and completely shut down without any prior warning. All vehicle systems—including electrical—failed simultaneously. This included the dashboard, steering assistance, and emergency lights, which significantly compromised my safety. I was unable to alert surrounding drivers or move the vehicle out of the traffic lane. There were multiple cars behind me, and I was placed in an extremely unsafe situation due to the sudden loss of control and inability to signal or restart the vehicle. I immediately contacted emergency services, and a police officer arrived approximately 10 minutes later to assist. Roadside assistance later pulled diagnostic code p0016 from the truck’s computer. I have since learned that this code corresponds to a known engine timing defect and is the subject of a recent GMC recall issued just days prior to the incident. The failure occurred without any warning lights, messages, or symptoms beforehand. The vehicle is now with a GMC dealer and is available for inspection upon request. To my knowledge, the issue has not yet been independently confirmed, but I believe it is directly connected to the recalled component.

2023 GMC 1500 sierra denali ultimate tailgate opens without being commanded. This has happened approximately three (3 ) times in the last two months while being driven with the most recent incident occurring today, 04/27/2025. There are no warning lights indicating when a tailgate opens while the vehicle is being driven.

Hello, I wish to report this injury / incident with the failure of the power running boards on my 2022 GMC Sierra 1500 denali limited. There are no warning lamps on the vehicle. The truck is regularly serviced and inspected. The truck recently had a multi-point inspection at the dealer. The power running boards started to come out after I opened my door, as I stepped down, the steps retracted and went back in causing me to fall hard on the ground and smash my knees. Driver and passenger sides are now acting up, even with the truck parked and locked, passenger side wants to go in and out on its own and sometimes extends to the tire. As I researched this problem, I found out that others have had similar issues with the same vehicles that have these power running boards. I removed the fuse now to prevent further injuries.

Driving on hwy at 60 mph on regular day going home and trucks all off sudden started rattling and engine knocking very loud , engine started crashing loosing power , has to merge to side of road and call tow truck.

Tailgate opened while in park. Closed garage door. Came back out to leave and garage door got caught on tailgate that had released open on its own causing body damage.

Just purchased this vehicle, at 84000 miles had engine failure and electrical issues while traveling down interstate with my family. Lost power steering and all warning lights popped up. Safely exited busy interstate -- avoided major accident. This engine should have been included in the recent GMC recall - after a diagnostic $7000. 00 plus to fix. Unsafe engine issue!! please help the consumer!!.

Esc error parking break not releasing dashboard lights started flashing check engine light came on.