2026 GMC Sierra 1500 Problems

See attached document for complaint.

Three different times now (most recent: 10/22/2026), I have had my truck completely shut off when coming to a stop on the highway/interstate. I always have auto start/stop disabled when I drive. When it happens, a message shows on the dash that says press start button. No other codes or check engine light. Thankfully it has started every time, but this is obviously a serious safety concern. After the second time it happened, I had the dealer (Woodhouse Buick GMC Omaha) look at it on 9/14/2026, but they couldn't find anything since there were no codes. I'm not sure if it is an electrical issue or this is related but my audio will stop working at times as well. Nothing from the radio or any blinker sounds. Sometimes it's static with a high pitch noise. 2026 GMC Sierra Elevation 5.3 EcoTec3 v8 10 speed

While driving the truck it randomly shuts down, message on dash says shift to park to restart. No check engine light comes on or any other message. When it does this, the truck goes into park. It has been to the dealership 3 times and has not been fixed!

On 10/15/2026 I was making a slow right-hand turn up a slight incline into a parking lot when the vehicle braked very hard and the transmission made a grinding noise. I looked at the dashboard, and it was showing that the truck shifted into park while I was driving. The electronic brake engaged as well. I tried putting the truck back into drive, but it would not go into drive. On the dash there was a Service Transmission warning. The push to start engine button still had the green LED on as if the vehicle was running. I pushed the start engine button and the engine started (I didn't realize until now that the engine had shut off). At this point the truck would shift into drive. Another point of note is that I had turned off the Auto Stop feature. I do this every time I start my trip. The truck will be looked at on 10/16/2026 by the dealership. I did report the problem to the service department of the dealership. This incident was the first time it ever happened and there was no warning.

My radio continues to suddenly reduce volume by approximately 70%. The volume will then come back for a second, then back down again. This can go one for several hours while on a trip, then suddenly back to normal. I have owned this truck for less than 3 months and have about 2500 miles on it. I was informed by a GM Service Technician that this has been an issue that GM is aware of but yet no remedy.

Three different times now (most recent: 10/22/2026), I have had my truck completely shut off when coming to a stop on the highway/interstate. I always have auto start/stop disabled when I drive. When it happens, a message shows on the dash that says press start button. No other codes or check engine light. Thankfully it has started every time, but this is obviously a serious safety concern. After the second time it happened, I had the dealer (Woodhouse Buick GMC Omaha) look at it on 9/14/2026, but they couldn't find anything since there were no codes. I'm not sure if it is an electrical issue or this is related but my audio will stop working at times as well. Nothing from the radio or any blinker sounds. Sometimes it's static with a high pitch noise. 2026 GMC Sierra Elevation 5.3 EcoTec3 v8 10 speed

I was approaching an intersection about to make a left turn as the turn signal was flashing yellow and my truck just stopped accelerating. If i had taken that turn i would have got hit and most likely cause a huge pile up because the amount of traffic going through. I put my hazard lights on and tried shifting my truck into park, and then back into drive, and it would not accelerate. I had to turn my truck off and on a few times for it to accelerate. There were no warning lights on my dash and the truck is brand new.

Vehicle: 2026 GMC Sierra 1500 AT4 (3.0L LZ0 Duramax Diesel) Current Mileage: ~16,500 miles Check Engine Light Status: NO Check Engine Light active Description of Incident & Symptoms: •Interstate Incident: While driving at highway speeds, a severe drivetrain vibration occurred (felt like a rear wheel weight flew off). •Dashboard Warnings: Within 5 minutes, intermittent "Traction Control" and "Forward Collision Warning" alerts appeared on the dash, accompanied by a sudden drop in engine power. •Engine Noise & Idle: Once safely pulled over, the engine exhibited a loud mechanical knock and a very rough, unstable idle. •Extended Crank: After shutting the engine off and waiting a few minutes, restarting the truck took roughly twice as long as normal (long crank/delayed start)

While driving on a public road, the 6.2L L87 V8 stalled without warning. There was heavy smoke and an oil trail of about 300 yards behind the truck. The engine would not restart, and the transmission would not shift into neutral. The truck was moved a short distance off the road and towed the next day to the selling GMC dealer. Odometer was 4,663 miles. Oil life remaining was 38 percent. The truck was stock, with no modifications, and was operated on premium fuel. No warning lamp was noticed before the stall. The failed engine is at the dealer and currently under inspection. The dealer inspection is not finished, and no written cause has been provided. This is a sudden loss of propulsion. Please associate this report with Engineering Analysis EA26005 concerning connecting-rod and crankshaft failures in the GM 6.2L L87 engine.

Truck was sold to me and the dealership said the truck did not have the defect and the oil was changed to a thicker oil as a precaution. 4,000 miles later the engine failed, was diagnosed as catastrophic engine failure due to the known recall, and was replaced, new engine is now making the same rod knocking noise.

On 10/15/2026 I was making a slow right-hand turn up a slight incline into a parking lot when the vehicle braked very hard and the transmission made a grinding noise. I looked at the dashboard, and it was showing that the truck shifted into park while I was driving. The electronic brake engaged as well. I tried putting the truck back into drive, but it would not go into drive. On the dash there was a Service Transmission warning. The push to start engine button still had the green LED on as if the vehicle was running. I pushed the start engine button and the engine started (I didn't realize until now that the engine had shut off). At this point the truck would shift into drive. Another point of note is that I had turned off the Auto Stop feature. I do this every time I start my trip. The truck will be looked at on 10/16/2026 by the dealership. I did report the problem to the service department of the dealership. This incident was the first time it ever happened and there was no warning.

At 20 mph, the truck experienced unintended acceleration during normal braking. Light braking did not trigger the safety brake-override system, and the engine continued to pull forward until I was forced to mash the brake pedal completely down to overpower the engine.

In early June 2026 I discovered a sheared pin on the front control arm of my 2026 GMC Sierra 1500 AT4X (VIN [XXX]), sold to me new by Parks GMC, Kernersville NC, with a dealer-installed Performance Package modifying the factory suspension. I delivered the truck to Parks GMC for warranty repair. The dealer represented it as a 1-2 day job. The truck was out of service approximately 2 weeks. The dealer sub-contracted the work to a third-party shop (CCV). At pickup, the dealer provided written documentation stating the repair was NOT PERFORMED. Neither the dealer nor I has been able to obtain any documentation from CCV describing what, if anything, was actually done to the vehicle. THREE UNRESOLVED SAFETY CONDITIONS: SHEARED FRONT CONTROL ARM PIN — original failure, status of repair unknown and undocumented. TIRE-TO-BODYWORK CONTACT — front tires intermittently rub the inside of the wheel wells during normal driving and steering, causing visible damage to the plastic mud guards. Tire-to-bodywork contact creates risk of sidewall failure, sudden air loss, and loss of vehicle control. FRONT RIGHT SUSPENSION CREAK — loud, persistent creak from the front right suspension during low-speed driving and steering inputs. Present at service drop-off, never addressed. Consistent with a worn, loose, or improperly installed suspension component. I escalated to Parks GMC management and GMC Customer Assistance. Parks has not provided a written repair plan, no decision-maker has contacted me, and the only response has been "looking into it." GMC Customer Assistance declined to assign a District Service Manager. I am filing to document these suspension and tire safety conditions in the federal database against this VIN and to request NHTSA evaluation of whether further action is warranted. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

While driving on the highway, the steering became much more stiff, and then I heard metallic clanging sounds for a few seconds. The dashboard said press start to start Vehicle. I pressed start while going 30 miles an hour and all lights and instrument clusters went black. I pulled into the grass median where the truck would not start or shift gears. Truck was towed to a GMC dealership

My 2026 GMC Sierra has an oil-canned roof from a touchless car wash because the sheet metal lacks structural rigidity. This caused the roof to buckle and caused a permanent fold in the roof of the truck. There is already documented issues for this exact problem on the newer GMC Canyons and Chevrolet Colorado mid-sized trucks. Bulletin for reference NHTSA Official TSB #23-NA-209 PDF. I leased the vehicle on 6/19/2026 and this happened on approximately 7/7/2026. The vehicle only has 1,480 miles on it as of this date.

The tailgate intermittently opens while driving or parked

In early June 2026 I discovered a sheared pin on the front control arm of my 2026 GMC Sierra 1500 AT4X (VIN [XXX]), sold to me new by Parks GMC, Kernersville NC, with a dealer-installed Performance Package modifying the factory suspension. I delivered the truck to Parks GMC for warranty repair. The dealer represented it as a 1-2 day job. The truck was out of service approximately 2 weeks. The dealer sub-contracted the work to a third-party shop (CCV). At pickup, the dealer provided written documentation stating the repair was NOT PERFORMED. Neither the dealer nor I has been able to obtain any documentation from CCV describing what, if anything, was actually done to the vehicle. THREE UNRESOLVED SAFETY CONDITIONS: SHEARED FRONT CONTROL ARM PIN — original failure, status of repair unknown and undocumented. TIRE-TO-BODYWORK CONTACT — front tires intermittently rub the inside of the wheel wells during normal driving and steering, causing visible damage to the plastic mud guards. Tire-to-bodywork contact creates risk of sidewall failure, sudden air loss, and loss of vehicle control. FRONT RIGHT SUSPENSION CREAK — loud, persistent creak from the front right suspension during low-speed driving and steering inputs. Present at service drop-off, never addressed. Consistent with a worn, loose, or improperly installed suspension component. I escalated to Parks GMC management and GMC Customer Assistance. Parks has not provided a written repair plan, no decision-maker has contacted me, and the only response has been "looking into it." GMC Customer Assistance declined to assign a District Service Manager. I am filing to document these suspension and tire safety conditions in the federal database against this VIN and to request NHTSA evaluation of whether further action is warranted. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

The contact owns a 2026 GMC Sierra 1500. The contact stated that after purchasing the vehicle, there was no Owner’s Manual in the vehicle. The contact inquired about the Owner’s Manual and was informed by the dealer that an Owner’s Manual was no longer printed. The contact checked online and became aware of FMVSS 225, which was related to the Owner’s Manuals for similar vehicles. The contact researched NHTSA Campaign Number: 25V815000 (Equipment), addressing the lack of an Owner’s Manual for 2026 Chevrolet Silverado 1500, 2500, and 3500 vehicles. The manufacturer was not notified of the issue.

Subject: General Grabber Tire Failure at 13,464 Miles I am reporting a catastrophic General Grabber tire failure on my 2026 GMC Sierra at 13,464 miles\. I am concerned that the failure may involve a defect in materials or workmanship and am requesting that it be recorded and reviewed as a potential safety defect\. The tire is a General Grabber HTS60, size 275/60R20\. Photos of the failed tire are available\. I can provide the tire’s DOT identification number if needed\. After the failure, we contacted a GMC dealership in [XXX], and attended an appointment at Bergstrom in [XXX]\. We received conflicting information from the dealerships and GMC customer service about warranty coverage\. Because I needed a usable vehicle and could not wait for the warranty dispute to be resolved, I purchased a replacement tire from Walmart and my husband installed it\. My safety concern is that this tire suffered a catastrophic failure at only 13,464 miles\. The cause has not been confirmed, and I would like NHTSA to assess this report alongside any similar complaints\. Please advise what additional information or documentation would assist your review\. [XXX] Phone: [XXX] Vehicle: 2026 GMC Sierra Mileage at failure: 13,464 Tire: General Grabber HTS60, 275/60R20 INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

The contact owns a 2026 GMC Sierra 1500 equipped with Bridgestone Tires, Tire Line: Dueler A/T, Tire Size: 275/60/R20, DOT Number: 17XW09K63. The contact stated that the sidewall around the bead of the four tires were cracked. The tires were dry rotted. The tires were the original equipment. The dealer was notified of the failure in person. The failure mileage was approximately 13,300.

Ac not working properly. Ac blows air to defrost vents foging front windshield and side windows causing bad visibility

In early June 2026 I discovered a sheared pin on the front control arm of my 2026 GMC Sierra 1500 AT4X (VIN [XXX]), sold to me new by Parks GMC, Kernersville NC, with a dealer-installed Performance Package modifying the factory suspension. I delivered the truck to Parks GMC for warranty repair. The dealer represented it as a 1-2 day job. The truck was out of service approximately 2 weeks. The dealer sub-contracted the work to a third-party shop (CCV). At pickup, the dealer provided written documentation stating the repair was NOT PERFORMED. Neither the dealer nor I has been able to obtain any documentation from CCV describing what, if anything, was actually done to the vehicle. THREE UNRESOLVED SAFETY CONDITIONS: SHEARED FRONT CONTROL ARM PIN — original failure, status of repair unknown and undocumented. TIRE-TO-BODYWORK CONTACT — front tires intermittently rub the inside of the wheel wells during normal driving and steering, causing visible damage to the plastic mud guards. Tire-to-bodywork contact creates risk of sidewall failure, sudden air loss, and loss of vehicle control. FRONT RIGHT SUSPENSION CREAK — loud, persistent creak from the front right suspension during low-speed driving and steering inputs. Present at service drop-off, never addressed. Consistent with a worn, loose, or improperly installed suspension component. I escalated to Parks GMC management and GMC Customer Assistance. Parks has not provided a written repair plan, no decision-maker has contacted me, and the only response has been "looking into it." GMC Customer Assistance declined to assign a District Service Manager. I am filing to document these suspension and tire safety conditions in the federal database against this VIN and to request NHTSA evaluation of whether further action is warranted. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)