2023 GMC SIERRA 1500 Complaints

I own a 2023 GMC Sierra 1500 Denali Ultimate equipped with the 6.2L L87 V8 engine. The vehicle previously experienced an engine failure that resulted in the complete replacement of the 6.2L engine by an authorized GMC dealership. The replacement engine was installed at approximately 76,316 miles. After approximately 1,000 miles of driving with the replacement engine, at approximately 77,354 miles, the vehicle displayed a check-engine/service warning and experienced abnormal transmission shifting. I returned the vehicle to the GMC dealership for diagnosis. The dealer documented DTC P0747, identified as “Transmission Control Solenoid Valve 1 Stuck On,” and recommended replacement of the transmission control valve body at a quoted cost of $2,665.85 plus tax. The dealership has stated that this transmission condition is unrelated to the recent engine replacement. However, because the condition appeared only approximately 1,000 miles after a complete engine replacement, I have asked General Motors to investigate whether the current failure could be associated with the previous engine failure, the engine replacement procedure, or other related vehicle systems. I have opened a case with General Motors Customer Assistance and have deferred the customer-paid valve-body repair while GM reviews the matter. I am submitting this complaint so NHTSA/ODI has a record that this vehicle experienced a major 6.2L L87 engine failure requiring complete engine replacement and then, approximately 1,000 miles after that replacement, developed a check-engine warning, abnormal transmission operation, DTC P0747, and a condition requiring replacement of the transmission control valve body. I can provide the engine-replacement repair order, current diagnostic documentation, mileage records, dealer repair estimate, and GM case information upon request.

My 2023 GMC Sierra 1500 SLT 4WD currently at 67659 miles was taken in to the dealer because of excessive jerk when accelerating or trying to reverse, diagnostic scan failed for check engine and ABS trouble codes. The scan return code PO747 indicating transmission pressure control solenoid “A” was stuck on for a predetermined period of time. The recommended repair is replacement of automatic transmission, solenoid control valve body. I’m aware that GM has issued a TSB 25–NA-255 and special coverage N24245441–02 addressing this exact failure on the GM 10 speed and that GM previously issued a related recall N242454440 addressing this exact failure on the GM 10 speed transmissions, and that GM previously issued a related recall for this citing rear wheel lock up risk associated with transmission valve condition. My vehicle scan showed an ABS failure at the same time as a transmission. code, consistent with the safety risk. GM has already acknowledged and its own recall documentation however I was told to contact NHTSA to document the safety risk and request investigation of the scope of this defect across affected models years and vehicles as mine seems to have fallen short. I previously owned a 2021GMC vehicle same model that experience the identical transmission valve body failure that vehicle could not be repaired in a reasonable time and I ultimately experience financial loss and had to replace a vehicle now I’m experiencing the same defect on the vehicle purchased (this one) with significantly fewer miles than would be expected for a major transmission failure, indicating that this may be a reoccurring manufacturing design defect rather than an isolated incident. Thank you for your time and I hope this issue can be resolved as I do love the truck otherwise however safety first. Thank you

The GMC Sierra has a known issue from the manufacturer in which the power sliding rear window can start to leak water into the cab of the truck during rain or other impact with outside water. This issue allows water into the cab through a cracked or faulty seal, which impacts visibility and allows water to penetrate inside, producing risk for moisture to collect on the back window and potentially cause mold to grow inside, further creating a health risk. Further, the water intrusion can lead to interior damage, as well as potentially cause electrical failure and unsafe operation. This is a known issue dating back to January 2019 when GM issued Technical Service Bulletin 18-NA-383 and has continued to be revised since. The component has been reviewed and inspected by the dealer and is known to the manufacturer; however, they are unwilling to fix without cost as this is not a recall.

The upper grille trim piece came off while driving down I20 between Hudson Oaks and Willow Park. I was doing between 60-65 mph. It could’ve hit other vehicles behind me, or to the side of me. This piece is a known issue and the 2022’s have a recall but not the 2023 model years. No signs of this being about to break.

The upper grill chrome trim blew off at highway speed. The plastic brackets holding it in place sheared off. This was a known defect resulting in 70,000 recalled trucks for the prior year model (2022), but for some reason isn't covered for 2023. Same exact issue

The fuel pump control module went bad and the vehicle shut off while driving. The vehicle is only 3 years old. Everyone I know with a GM truck or SUV has had the same issue and the dealer service writer even told me they get at least 6 vehicles with the same issue per week. There is already a recall for GM SUV's for 2021-22 model years but not for anything else even though many other vehicles have the same issue. They replaced the module under warranty but it is all but guaranteed to just keep happening.

Whilst driving down the highway at 65 mph the plastic front grill deflector broke off and slammed into my windshield and the vehicle behind me. Luckily the vehicle behind me sustained no damage other than how frightened she and her children were. This is a known issue and was subject to a recall for the 2022 GMC Sierra Denali's. Nothing has changed between the 2 models as far as I can tell and it's the exact same grill deflector. When I informed the dealership of this they told me it would be a $950 repair out of pocket. First of all, it is unacceptable for a $75,000 vehicle to have a plastic component that can just break off and become an immediate and unavoidable hazard on the highways. The recall MUST be extended to these vehicles. I have reached out to GM and they confirmed it would be an out of pocket expense, but I am escalating the situation. Thank you!

The contact owns a 2023 GMC Sierra 1500. The contact stated that while driving at an undisclosed speed, the brake pedal was depressed; however, the brakes failed to respond as needed. The vehicle was towed to the dealer to be diagnosed. The vehicle was diagnosed with an inoperable battery, which caused the brake module to fail, preventing the brakes from operating as intended. The vehicle was repaired. The manufacturer was not made aware of the failure. The failure mileage was approximately 29,000.

The OnStar module in the truck is broke it affects all communications. The truck has including things like let me know what the speed limit is. It happened after they did a software update, which seems a little fishy because there was nothing wrong with it before I understand. Some people were having problems with this module, causing their batteries to die, but now I’m the one having issues and they won’t seem to fix it unless I pay them $900.

My truck threw the code p0747 for fail valve body. When I do my research its a common problem. GM is stating my truck isnt covered.