2020 GMC Sierra 1500
Problems, recalls and owner-reported issues
Engine is the leading concern among 468 owner complaints filed for this model year. This is the 7th highest complaint count among 26 Sierra 1500 model years with reports.
Of the 2020 reports, 12 involved a crash and 5 involved a fire. 13 people were injured.
What owners report most often
Recalls and investigations
Power train, automatic transmission, control module, softwareFeb 12, 2026
General Motors, LLC is recalling certain 2020 Chevrolet Silverado 2500, 3500, GMC Sierra 2500, 3500, and 2020-2022 Chevrolet Silverado 1500 and GMC Sierra 1500 vehicles that may have been repaired incorrectly under recall 24V797. The transmission control valve may fail and cause the rear wheels to lock up.
Rear wheel lock up increases the risk of a crash.
Dealers will inspect the vehicles and update the transmission control software, free of charge. Owner notification letters were mailed March 6, 2026. Owners may contact GMC customer service at 1-800-462-8782 or Chevrolet customer service at 1-800-222-1020. GM's number for this recall is N252516560. Vehicle Identification Numbers (VINs) involved in this recall became searchable on NHTSA.gov on February 12, 2026.
Campaign 26V083000 on NHTSA.gov
Power train, automatic transmission, control module, softwareOct 24, 2024
General Motors, LLC (GM) is recalling certain 2020-2022 Chevrolet Silverado 1500, 2500, 3500, GMC Sierra 1500, 2500, 3500, 2021 Cadillac Escalade, Escalade ESV, Chevrolet Tahoe, Suburban, GMC Yukon, and Yukon XL vehicles equipped with diesel engines. The transmission control valve may fail and cause the rear wheels to lock-up.
Rear wheel lock-up can increase the risk of a crash.
Dealers will install new transmission control module software, free of charge. GM will provide a special coverage program to cover the repair of transmissions that are identified by the remedy software as containing a defective control valve. Owner notification letters were mailed December 12, 2024. Owners may contact GM customer service at 1-888-988-7267, Cadillac customer service at 1-800-458-8006, GMC customer service at GMC 1-800-462-8782 or Chevrolet customer service at 1-800-222-1020. GM's number for this recall is N242454440.
Campaign 24V797000 on NHTSA.gov
Tires, temporary/emergency spare tireDec 16, 2021
General Motors (GM) is recalling certain 2019-2021 GMC Sierra 1500 and Silverado 1500 vehicles equipped with certain accessory road tires and a 17" spare tire. The 17" spare tire provided with the vehicle is not compatible for use with the accessory wheels, which can cause the anti-lock brake system (ABS) to not function properly under certain conditions.
An ABS system that does not function properly can increase the risk of a crash.
Dealers will provide a new 17" spare tire and wheel assembly that is compatible with the accessory wheels, free of charge. Dealers will also apply a new spare tire information label, and provide owners with an owner's manual insert clarifying which spare tire to use with the accessory road tires and with the 17" original tires. Owner notification letters were mailed February 7, 2022. Owners may contact GM customer service at 1-800-462-8782 or GMC customer service at 1-800-462-8782. GM's number for this recall is N212346510.
Campaign 21V985000 on NHTSA.gov
TiresFeb 25, 2021
General Motors LLC (GM) is recalling certain 2020 Buick Enclave, Cadillac XT4, XT5, Escalade, Escalade ESV, Chevrolet Suburban, Tahoe, Traverse, GMC Yukon, Yukon XL, 2018-2021 Chevrolet Express, GMC Savana, 2019-2020 Chevrolet Blazer, Silverado 1500, GMC Acadia, Sierra 1500, and certain Continental tires sold to the aftermarket for various model year 2018-2021 vehicles. The affected tires were cured for too long during production.
Over cured tires may develop a break in the sidewall resulting in sudden air loss or a belt edge separation which could lead to a tread/belt loss. Either condition can cause a loss of vehicle control, increasing the risk of a crash.
GM will notify owners, and dealers will inspect the tires, replacing them as necessary, free of charge. The recall began March 22, 2021. Owners may contact GMC customer service at 1-888-988-7267, Buick customer service at 1-866-608-8080, Chevrolet customer service at 1-800-222-1020 or Cadillac customer service at 1-800-458-8006. GM's number for this recall is N212329050.
Campaign 21V115000 on NHTSA.gov
Seat beltsDec 17, 2020
General Motors, LLC (GM) is recalling certain 2019-2021 Chevrolet Silverado 1500 and GMC Sierra 1500, 2021 Chevrolet Suburban and Tahoe and GMC Yukon XL and 2020-2021 Chevrolet Silverado 2500 and 3500 and GMC Sierra 2500 and 3500 vehicles. The seat belt brackets may not be secured to the seat frame in the front-row center seating position.
If a seat-belt bracket is not secured, the seat belt may not properly restrain an occupant in the front-row center seat position, increasing the risk of injury in a crash.
GM will notify owners, and dealers will inspect left-side and right-side front-row center seat-belt bracket attachments and reassemble it correctly as necessary, free of charge. The recall began January 26, 2021. Owners may contact GMC customer service at 1-800-462-8782, Chevrolet customer service at 1-800-222-1020. GM's number for this recall is N202314670.
Campaign 20V792000 on NHTSA.gov
TiresNov 5, 2020
General Motors LLC (GM) is recalling certain 2020 Buick Enclave, Cadillac XT5, GMC Acadia and Chevrolet Traverse vehicles and 2020-2021 Chevrolet Silverado 1500, GMC Sierra 1500 vehicles. The vehicles may have been manufactured with Continental tires that were overcured.
Overcured tires may experience a carcass break in the sidewall resulting in a sudden air loss or could develop a belt edge separation which could lead to partial or full tread/belt loss. Either condition increases the risk of a crash.
GM will notify owners, and dealers will inspect vehicles and replace tires that have DOT number and production mold number combinations identified by Continental, free of charge. The recall began December 17, 2020. Owners may contact GMC customer service at 1-888-988-7267, Buick customer service at 1-866-608-8080, Chevrolet customer service at 1-800-222-1020 or Cadillac customer service at 1-800-458-8006. GM's number for this recall is N202319030.
Campaign 20V684000 on NHTSA.gov
Power train, driveline, driveshaftOct 22, 2020
General Motors LLC (GM) is recalling certain 2019-2020 Chevrolet Silverado 1500 and GMC Sierra 1500 and 2020 Chevrolet Silverado 2500 trucks. One of the driveshaft joints may not have been properly welded, causing the driveshaft to separate while the vehicle is moving.
If the driveshaft separates, there may be a loss of propulsion, increasing the risk of crash.
GM will notify owners, and dealers will replace the driveshaft, free of charge. The recall is expected to begin December 2020. Owners may contact Chevrolet customer service at 1-800-222-1020 or GMC customer service at 1-888-988-7267. GM's number for this recall is N202314870.
Campaign 20V650000 on NHTSA.gov
Air bags, side/window, curtain, inflatorJul 30, 2020
General Motors, LLC. (GM) is recalling certain 2020 Buick Enclave, Cadillac XT5 and XT6, Chevrolet Blazer, Silverado 1500, 2500 and 3500 and Traverse and GMC Acadia and Sierra 1500, 2500 and 3500 vehicles. The diffuser component of the Roof-Rail Air Bag (RRAB) inflator may not have been properly crimped to the inflator and could separate from the inflator during air bag deployment.
If the diffuser separates from the inflator during deployment, RRAB performance may be degraded, increasing the risk of injury in a crash.
GM will notify owners, and dealers will replace the suspect RRAB modules, free of charge. The recall began September 3, 2020. Owners may contact Chevrolet customer service at 1-800-630-2438, Cadillac customer service at 1-800-333-4223, or Buick customer service at 1-800-521-7300. GM's number for this recall is N202305380.
Campaign 20V446000 on NHTSA.gov
Service brakes, hydraulic, foundation components, disc, caliperFeb 27, 2020
General Motors LLC (GM) is recalling certain 2020 Chevrolet Silverado 1500 and GMC Sierra 1500 vehicles. The bolts used to attach the front and/or rear brake calipers may have not been heat treated and may break under load.
Broken caliper bolts can reduce brake performance or interfere with wheel rotation and increase the risk of a crash.
GM will notify owners, and dealers will replace the brake caliper bolts, free of charge. The recall began March 23, 2020. Owners may contact Chevrolet customer service at 1-800-222-1020 or GMC customer service at 1-866-522-9559. GM's number for this recall is N202294420.
Campaign 20V116000 on NHTSA.gov
Electrical system, 12v/24v/48v battery, cablesDec 12, 2019
General Motors LLC (GM) is recalling certain 2019-2020 Chevrolet Silverado 1500 and GMC Sierra 1500 trucks. The battery positive (B+) cable rings may have been manufactured with excessive glue, potentially causing an intermittent electrical connection between the B+ cable and alternator.
An intermittent electrical connection between the B+ battery cable and the alternator could cause the vehicle to stall, increasing the risk of a crash. The intermittent connection could also lead to electrical arcing, which could generate sufficient heat to damage surrounding material, increasing the risk of a fire.
GM will notify owners, and dealers will inspect for the presence of glue or other contamination at the B+ cable attachment to the alternator and clean the connection and reattach the B+ cable connection, as necessary. If arcing has damaged the cable, nut, or alternator, the dealer will replace the damaged components. All services will be performed free of charge. GM issued owners an interim notification on February 4, 2020. GM issued second notice and the recall began March 9, 2019. Owners may contact Chevrolet customer service at 1-800-222-1020 or GMC customer service at 1-888-988-7267. GM's number for this recall is N192273510.
Campaign 19V888000 on NHTSA.gov
Fuel system, gasoline, delivery, fuel pumpNov 21, 2019
General Motors LLC (GM) is recalling certain 2020 Cadillac Escalade, Escalade ESV, Chevrolet Camaro, Silverado 1500, Suburban, Tahoe, GMC Sierra 1500, Yukon, and Yukon XL vehicles. The fuel pump may be missing a pressure regulator, allowing for over-pressurization of the fuel system.
Over-pressurization can crack the fuel pump and cause leaks, increasing the risk of a fire in the presence of an ignition source.
GM will notify owners, and dealers will replace the fuel pump, free of charge. The recall began December 18, 2019. Owners may contact Cadillac customer service at 1-800-333-4223, Chevrolet customer service at 1-800-222-1020, or GMC customer service at 1-888-988-7267. GM's number for this recall is N192283991.
Campaign 19V837000 on NHTSA.gov
Seat belts, pretensionerNov 14, 2019
General Motors LLC (GM) is recalling certain 2019-2020 Chevrolet Silverado 1500 and GMC Sierra 1500, and 2020 Silverado 2500, Silverado 3500, Sierra 2500, and Sierra 3500 vehicles equipped with carpet floor covering. When the front seat belt pretensioners deploy, hot gas may vent through an opening in the pretensioner bracket, possibly igniting the carpet.
A vehicle fire could result if materials ignite inside the vehicle.
GM will notify owners, and dealers will close off the opening in the pretensioner bracket, free of charge. The recall began December 13, 2019. Owners may contact Chevrolet customer service at 1-800-222-1020 or GMC customer service at 1-888-988-7267. GM's number for this recall is N192270600.
Campaign 19V814000 on NHTSA.gov
Representative owner complaints: power train
97 reports, newest first. Show all
Power train, Vehicle speed control, Sep 28, 2026
The vehicle in questions was purchased with less than 5 miles in year 2020. This vehicle was dropped off at MAC HAIK CHEVOLET MADISON MS on September 25, 2026. I was advised on September 28, 2026, that the vehicle was test driven with the scan tool connected, Graph Torque converter slip, found over 100 RPM slip when torque converter engaged and causing shutter at highway speeds, also felt 1-2 and 2-1 harsh downshift, check fluid condition was black and smelled burnt, replace transmission assembly, flush cooler, program transmission control module and perform clutch fast learn. Estimated cost of $8k
Power train, Electrical system, Engine, Sep 15, 2026
5/5/25 woke up back seat entire truck flooring soaking wet back glass cracked. 4/8/25 transmission went out 117,000 miles 7/3/25 exhaust leak and placed nox 1. 7/8/25 127551 mileage exhaust leak replace gaskets, belt , tensioner, and pulley, 6/8/2025 3 knock sensors replaced and replaced intake manifold.
Power train, Sep 14, 2026
Transmission shifting hard in first few gears and only 87,000 miles on Transmission.
Power train, Engine, Sep 9, 2026
Powertrain issues and a chassis issue that is extremely dangerous.Tailgate on rare occasions falls open by itself. There is a design flaw in the placement of the catalytic converters. The heat is burning up the fluid. I could not believe my eyes when I serviced the transmission. This is another shortcut by GM to save on the extra wiring needed for the oxygen sensors (2)in the converters and the two oxygen sensors downstream of the converters. There is plenty of room for the converters further down by the tail shaft to drive shaft connections. This is GM’s way of being cheap. Here’s the problem. The converters get way too hot. The fill plug for the transmission which is behind a low rent heat shield crumbled into my hands from excessive heat buildup. GM knows there is a problem with the fluid breaking down. Their bandaid answer is to use Mobil 1 fluid instead of the recommended Dexron 6. What needs to happen is a safety recall issued for the unwanted tailgate deploying all by itself. There needs to be a redesign in the exhaust system. The Transmission (8 Speed) has a catalytic converter exactly on both sides and the crossover pipe runs directly under the transmission sump pan. No wonder they are having issues with transmissions burning up. THIS IS A FIRE HAZARD !!! With the converters being so close to the exhaust manifolds, a leak from the engine or the transmission would be enough to ignite and possibly kill the occupants. All in the name of saving a few cents in wiring. Myself, I am a retired GM Mechanic. I started working at Sewell Cadillac in [XXX] in 1975. I have held the title of ASE Master Tech. Cadillac Master Tech. I have been a GM Shop Foreman and A GM Service and Parts Director in my Career. I retired from Federal Express as in charge of Fleet Maintenance and GSE(Aircraft Equipment). I have certifications from Mercedes, BMW, Toyota, Commander Loaders, Goodyear, and more. Given the right set of circumstances, it could end very badly. Dangerous Truck ! INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)
Power train, Vehicle speed control, Other or unspecified, Aug 26, 2026
This truck was bought brand new by my father. Around 38,000 miles it begin having issues with shifting which eventually got worse. When I searched google for issues many others on different pages have had the same issues. The shifting would be so rough it feels like you're being hit by another vehicle. This could cause accidents for anyone who cannot afford to fix these known issues by GMC. I was told today by my local dealership their transmissions for my specific truck is on backorder. Should that not indicate an issue when this truck is a 2020. But to my father having a stroke I was not able to handle this issue sooner as he was very ill for four years and passed last year. The truck was not the priority at the time.
Power train, Engine, Aug 26, 2026
High pressure fuel pump went at 80k and now on my 2nd transmission under 100k miles this is absolutely absurd
Power train, Engine, Aug 24, 2026
The 5.3L Engine active fuel management failure problem. This known problem with the GMC motors was not disclosed by any dealerships or the manufacturer. While driving down the roadway, the truck had an engine malfunction and I was fortunate enough to be able to safely pull over. The check engine light activated and I took it to the dealer the next day. I was informed by the dealer that this was a known, common issue that GM was aware of but was not offering assistance. I had to pay $11,000 out-of-pocket because of this.
Power train, Electrical system, Engine, Aug 24, 2026
Our 2020 GMC SIERRA 1500 has suffered catastrophic systems and engine failure including the brakes multiple times for almost 4 years. It has happened in high traffic and on the interstate each time having to be coasted off of the road to come to a rolling stop. There have been nine repair attempts with GM dealers repeatedly stating the issues were repaired and returning our vehicle to us. We began making the CEO and Executive team aware of the potentially deadly safety hazards including the fact that I, [XXX] am disabled and power wheelchair dependent requiring a truck that can carry my power wheelchair. We have sent numerous emails to Ms. [XXX] and the Executive team numerous times informing them in detail, each time, of all issues involved. We started communicating via phone and email with customer care to no avail. All attempts at repair finally ended in complete engine failure leaving us with an estimate to replace the engine of over $13,000. We have also, submitted a detailed complaint to the Attorney General’s Office and after review were given the Case # TCP - XXX. I will attach the Complaint and Addendum sent to the Attorney General along with two of the emails sent to Ms. [XXX] and her team informing her of all issues with the truck. They took no action to actually help us get this truck off of the road knowing it was having catastrophic engine and system failure and that it had to be driven to transport a disabled power wheel dependent with severe medical issues and the medically necessary power wheelchair. I am also attaching the earliest OnStar Diagnostic notice of Engine, Transmission and Emissions system issues from May of 2023. The issues have remained the same from the beginning only worsening though my husband has only driven the truck in town on slower less busy streets learning how to make adjustments such as pumping the brakes and starting and stopping the truck to keep it going. My carrier is installed and yet it is undrivable. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)
Power train, Engine, Aug 6, 2026
"While driving, the vehicle suddenly experienced a flashing check engine light, an Electronic Stability Control (ESC) warning light, and violent steering wheel vibrations. The vehicle suffered a severe loss of power and misfired, creating an immediate traffic hazard. The dealership diagnosed the issue as a catastrophic mechanical lifter failure on the 5.3L V8 Ecotec engine with Dynamic Fuel Management (DFM). Despite the dealer replacing an entire bank of lifters, the engine continues to misfire and vibrate. This premature valvetrain failure at only 36,000 miles is a known design defect that causes sudden engine stalling and disables critical safety features like stability control while the vehicle is in motion, presenting a severe crash risk."
Power train, Aug 3, 2026
My truck shudders when driving. It has 78,000 miles on it. It started shuttering around 73,000 miles. I baby my truck and don't do switch backs or hot rod around.
Suspension, Power train, Jul 17, 2026
My truck transmission beed jerking off and on for over a year. One time it lose power when i was driving and could have caused an accident. I took it to the dealership and they said i new a new transmission for $12000. Something just doesn’t seem right about this! I brought a brand new truck thats unsafe and its no recall for my model but other models with the same issue had a recall. I would just like some answers. I feel like i brought a lemon. Thanks for listening.
Power train, Jun 23, 2026
The contact owns a 2020 GMC Sierra 1500. The contact stated that upon taking the vehicle to the dealer for a transmission fluid flush and refill, the contact was informed that the transmission was inoperable, and the vehicle could not be driven to the residence. The dealer determined that the torque converter needed to be replaced. The dealer replaced the torque converter and advised the contact to drive over 1,000 miles for the issue to self-correct. The contact stated that the vehicle continued to shudder and drive bumpy while driving after 1,000 miles. The vehicle was taken back to the dealer, where the torque converter was replaced a second time; however, the failure persisted. The dealer informed the contact that the diagnostic test results were sent to the warranty company for the transmission replacement approval. The vehicle was not yet repaired. The manufacturer was not notified of the failure. The failure mileage was approximately 85,165.
Power train, Jun 10, 2026
The contact owns a 2020 GMC Sierra. The contact stated while driving at an undisclosed speed, the transmission hesitated and shifted unusually rough. No warning lights were illuminated. The vehicle was taken to an independent mechanic where it was diagnosed with a transmission valve issue. The contact was advised that the power train software needed to be updated. The contact was informed of an unknown recall; however, the VIN was not associated with a recall related to the failure. The vehicle was not repaired. The dealer was made aware of the failure. The manufacturer was not made aware of the failure. The failure mileage was approximately 88,000.
Power train, Other or unspecified, Jun 3, 2026
Transmission, going towards home up a mild hill, broke top of hill trans shifted to next gear, rear wheels locked up and tires squealed. doing around 40 mph. Took it directly into the shop, and the trans was destroyed inside. broken parts in the pan. Trans could not be repaired, had to get a new transmission. I limped to the dealership, just noisey under vehicle. There was special coverage till 115,000 mile, had 97,062 miles on it. Just like it blew up inside. I was without a vehicle for 5 weeks, but I did have an extended warranty which it paid all of it except $ 1404.01, and I had to pay 2 weeks of car rental for 893.00. The transmission $ 6782.97 , and I would like reimbursement for what I paid. I could only go 10 to 15 mph to the repair shop, which was 7 miles away. GM states it was something else at the dealership, but it was parts all over inside of the pan when they took it apart.
Power train, Engine, Fuel/propulsion system, May 29, 2026
I again have noticed intermittent pulsing at low to medium speeds. At roughly 1k-2k rpm the engine at or about 10-20 mph is pulsating or hesitating with an obvious pulse which you can see on the tachometer as well (bouncing.) It seems like there is either a computer, fuel flow or electric issue. Also, at speeds up to the 40 mph range, this is happening as well. Yesterday while towing a small 7'x12' empty dual axle trailer I noticed it again, I occasionally use my trailer to haul small loads up to 4500lbs. This has happened before but this time I decided to notate this on your site, since reading about ongoing problems with the 2020 6.2L GMC Sierra 1500. I was aware of the other following years, 2021-2024? issues and that is why I purchased this 2020 year model. My truck will be available for inspection when the request is sent to me. Safety was not an issue, I ran my truck most of the day. I have not yet notified my Chevrolet dealer, Roger Dean, Cape Coral, FL. My truck has not yet been inspected for this issue. There were not any lights or warnings on display at time of incidents. Thank you, [XXX] [XXX] [XXX] INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)
Power train, Engine, Apr 30, 2026
I’m scared to drive my vehicle because of the 6.2L V8 ongoing engine failures! I believe it to be unsafe for travel never knowing when the engine will fail. Now with over 1 Million failures of this engine!
Power train, Engine, Apr 21, 2026
After owning this truck a little over a year I’ve had to replace the transmission and now it’s in the because the motor sounds like a bag of marbles was put in it and the warranty company is a joke they only want to replace just the cam and lifters but yet the dealership hasn’t be authorized to go to the bottom of the motor to check it out this truck has been nothing but a lemon!!!!!
Power train, Mar 27, 2026
The contact owns a 2020 GMC Sierra 1500. The contact stated that while driving on several occasions at various speeds, the vehicle started shaking and slipped in and out of gear, with the message "Idle Transmission" displayed. The vehicle was pulled over and shifted into park(P) and then to drive(D). There was a loud banging sound coming from the rear of the vehicle. The vehicle was towed to an independent mechanic, where it was diagnosed with transmission failure. The contact was informed that the transmission needed to be repaired. The vehicle was not yet repaired. The manufacturer was not notified of the failure. The failure mileage was approximately 80,000.
Power train, Electrical system, Mar 20, 2026
Truck broke down with a rear-wheel lockup and had the transmission replaced in June 2025. In December 2025 and February 2026, truck lost power two times and entered limp mode while on a major highway and major interstate. The problem was misdiagnosed in June 2025, diagnosed properly in December 2025, but not properly repaired, and diagnosed properly in February 2026. All three times the vehicle had this issue, two of the same exact DTCs were present. This is a safety defect, and I have lost all confidence that the vehicle is reliable enough and safe enough for myself and my family.
Steering, Power train, Engine, Mar 5, 2026, crash
Hi, was driving Vehicle GMC 1500 Denali, vehicle Lost power, all Lites lite up on Dashboard, Vehicle Just lost power and i swerved off Road and sideswiped a Plant Holder on side of Road, damaging side passenger Rear door. I bought the truck to GMC Rvc and they said vehicle Blew Cam shaft and Lifters. I explained to them I'm very concerned for others safety in these Vehicles with the 6.2 Engine. Someone is going to get Killed or even a family. I did look up this vehicle its not listed in Recall, but this vehicle has same engine as ones in Recall. Rvc Gmc issued me a bill for repairs for the amount of $8185.20 and they stated they took 3k off invoice. I did Pay total Invoice....I'm just asking you to please look into this as this is defiantly an issue and this year should be listed on Recall as well.. Thanku for at least looking at this. My cell is [XXX] if you need to reach us...Thx.... INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)
Power train, Feb 27, 2026
Vehicle is shifting hard when switching gears. Typical with the recall and the valve body being the issue. Dealership is saying it is not covered by recall.
Power train, Feb 20, 2026
The contact owns a 2020 GMC Sierra 1500. The contact stated that while driving at an undisclosed speed, the vehicle unexpectedly sputtered. There was no warning light illuminated. The vehicle was taken to the dealer, where it was diagnosed with torque converter failure. The dealer determined that the torque converter needed to be replaced. The vehicle was repaired. The contact later stated that while driving at an undisclosed speed, the vehicle unexpectedly went into LIMP Mode. There was no warning light illuminated. On several occasions, the vehicle unexpectedly downshifted and lunged forward while stopped at a traffic light. There was no warning light illuminated during the failure. The dealer was contacted. The vehicle was not diagnosed or repaired. The manufacturer was made aware of the failure and referred the contact to the NHTSA Hotline for assistance. The failure mileage was approximately 97,000.
Power train, Feb 20, 2026
On Friday, January 30, 2026 while driving our 2020 GMC Sierra 1500, we experienced sudden loss of power and the motor making a faint rattling noise. The motor soon after began making a horrible sound - - it was obvious something was very wrong. This vehicle only had 31,995 miles on it at the of the issue. We had the truck towed to the dealer the following day for evaluation. Upon inspection, it was determined that the #5 lifter had collapsed and the left bank of lifters needed to be replaced at an estimated cost of $4500. There were no warning lamps or alerts on our app for over 24 hours. Once at the dealer, we explained to the service advisor that our research concluded that GM is fully aware of these issues and that they are under investigation for possible recall. Our service advisor then made a call to GM who agreed to cover this repair under warranty (which we appreciate and feel was the right thing to do). However, after additional research, we are concerned that the right bank of lifters will fail next, or even worse, catastrophic engine failure that GM will refuse to cover. It is our understanding that NTSB is aware of these issues and is in the process of conducting an investigation. I would like to have our issue added to the investigation.
Power train, Engine, Feb 17, 2026
My engine is projecting a ticking sound. Oil consumption is extreme.
Power train, Feb 7, 2026
My 2020 GMC Sierra 1500 experienced a premature transmission failure consistent with GM’s known 8-speed transmission defect. My safety and the safety of others were put at risk if/when the transmission occurs a temporary lockup which can/will cause the vehicle to stall on the highway, and potentially create a minor/major automobile incident if vehicle stalls. The vehicle was taken to dealership Capital Chevrolet Montgomery, AL where dealership technician diagnosed/confirmed the issue along with pictures of internal transmission failed components as well as recommended resolution for fix. The vehicle has been inspected by my out-of-pocket expense extended warranty company Endurance Warranty Services sub-contracted repair claims adjuster. No warning lamps, vehicle messages, or other symptoms of the problem prior to the failure were noticeable; the vehicle had multiple diagnostic scans prior to original sale and after sale to present no issues or trouble scans. the first issue appeared or was noticeable 12/08/2025. GM has refused action by asserting warranty expiration despite widespread knowledge of this defect. The vehicle has been out of service since December 8, 2025.