2023 GMC Sierra 1500: check engine light

Filed Oct 27, 2026 · Engine, Fuel system · FL

On XXX, at approximately 2:30am, about 30 hours after purchase, a 2023 GMC Sierra Denali Ultimate suffered catastrophic engine failure in [XXX] during a planned 20 hour trip. The vehicle had about 49,007 miles at purchase and 49,411 miles at the time of failure. The check engine light appeared during the trip. Over five hours into the journey, shortly after passing through a one-lane construction zone with no shoulder, the truck made noises, then lost driving power and began slowing among highway traffic. The dashboard displayed "LOW OIL PRESSURE STOP ENGINE," code P0016, and a transmission warning. I had to move into another lane to reach the shoulder. The sudden loss of propulsion at 2:30am created a serious crash risk because the truck could have been struck by nearby traffic or become disabled on the one-lane road without a shoulder. The engine had received the GM L87 recall remedy on XXX involving a change to 0W-40 oil. Despite this remedy, the engine failed while the vehicle was moving. The repair order lists replacements for the engine, radiator, oil cooler lines, intake manifold and gaskets, spark plugs and wires, water pump gaskets, high pressure fuel lines, fuel pump gasket, and battery. The GMC app currently lists a "Required Product Emission Recall" for the fuel pump power control module and states that module failure can interrupt fuel flow to the engine. However, the federal safety agency VIN lookup, refreshed XXX reports zero unrepaired recalls. The reason for this discrepancy is unknown, as is whether the fuel pump recall condition contributed to the incident. I am reporting this sudden loss of driving power and engine failure despite the prior L87 recall remedy because these conditions may pose a serious safety risk. Provide Your INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

Filed Oct 20, 2026 · Engine · 50,000 miles · TX

The contact owns a 2023 GMC Sierra 1500. While driving at 30 MPH, the vehicle jerked and lost motive power. The vehicle was restarted and driven at reduced power to the dealer, where unknown electrical repairs were performed. The failure persisted, and the vehicle was towed to a second dealer, Grissom Chevrolet (181 S Interstate 20 Frontage Rd, Pecos, TX 79772), who replaced the engine. However, the failure recurred, and the vehicle was towed back to the first dealer, who diagnosed that the spark plugs and other unknown parts needed to be replaced. After the dealer performed the unknown repairs, the check engine warning light illuminated when the contact's son-in-law picked up the vehicle. The contact's brother, an independent mechanic, diagnosed that the catalytic converter and other unknown parts needed to be repaired. The contact filed a lemon law claim. The manufacturer was notified of the failure by phone. The failure mileage was approximately 50,000.

Filed Oct 16, 2026 · Engine · MI

A 6.2 engine operated as expected for 75,000 miles. I turned a corner at an intersection, and had a loud knocking in the engine occur. For the first 75,000 miles, there wasn't any unusual engine noises or oil consumption.Seconds later the engine light illuminated on the dash, reduced engine power, and every safety light within the dash was going on and off. I managed to drive slow and return to my residence and have the truck towed to the dealership to have the engine replaced. As many have learned, the recall from GM states to either pass a PICO test and change to 0W-40, or have the engine replaced if necessary. My concern is that the replacement engine is the exact same engine with the exact same components that assuredly will fail due improper design, production, and overlooked components that attribute to such failure. The crankshafts are being found to have values of "peaks and troughs" within the finish that are many times out of given specifications. The extraneous pressures created by the Dynamic Fuel management system over time are creating stresses and friction that the designated oil and oil pump are not compensating for. These mechanical stresses over different durations, seem to be part of the cause of the engines failure. The replacement engine came with a warranty that only extends to an odometer reading of 150,000 miles. I no longer have confidence in a manufacturer that is enforcing false resolve upon a customer as a solution. The new engines of replacement have been failing as well. This result exhibits a fact that shouldn't be ignored. The new engines have the same components and are due to fail, just the same as the original. I would like the manufacturer to resolve this failure by offering a "true" solution. A proven remedy and a documented warranty that assures the manufacturer stands behind the product. GM sells a new product that fails and then recalls the engines to replace with the same failed components and lack of warranty.

Filed Sep 19, 2026 · Engine, Fuel system · OH

Addendum to previous submission # 11760415. At 15,033 mileage again multiple codes present along with a rough running engine. Dealership service dept confirmed on 9/17/2026 verification of 10 active codes , 2 pending codes triggering check engine light. Onstar notification as well of engine issue. Prominently codes P0016 & P0340 lead the list. PICO testing was stated to have failed two out of 3 parameters. Officially stated now as an engine defect which is being directed to be replaced with a remanufactured , not new , motor. Very fortunate to not have experienced dramatic failure ( loss of propulsion ) at highway speeds far from home. Even though this vehicle warning's persisted prior to this ultimate conclusion it was insisted that ultimate failure was necessary before any resolution would be instituted. A safety conundrum if you will. A high probability safety risk of continued use ( based on historical data on this known engine failure risk ) to ‘ prove ‘ it would fail like many others already have. A fair assessment of my personal experience.

Filed Sep 16, 2026 · Engine · TN

On 9-10-26 Engine spun rod bearings per the dealership repair order Miles 52,796 I was towing a car on a car trailer traveling down the interstate when the motor failed. I had my wife in the truck with me. No prior warnings just a check engine light right before engine failed. GMC dealer replaced engine and returned on 9-14-26. The truck had already had the recall to check the engine and replace the oil to a thicker oil.

Filed Sep 10, 2026 · Acceleration, Transmission · CO

Purchased above listed vehicle new in XXX. Immediately noticed a 'coolant' smell in cab. brought vehicle in for coolant smell issue on XXX and XXX. We were told that there was no issue until finally on XXX we were told the radiator needed to be replaced at OUR expense. XXX we received a letter from GMC advising the "engine coolant control valve" may fail. In XXX while driving on mountain roads (we live in [XXX]) the check engine light came on and while at 50 mph, the vehicle went into "limp mode" we lost power and speed was immediately reduced. We now know that a symptom of that valve failure is coolant smell in the cab of the car, a problem we had attempted to address with GMC from the beginning. We could have had a serious accident driving on a busy mountain road when this failure occurred. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

Filed Sep 9, 2026 · Engine · 12,998 miles · TX

The contact owns a 2023 GMC Sierra 1500. The contact stated that while driving 65 MPH, the engine made a clunking, knocking, and tapping sound. The engine was driving on seven of the eight cylinders. The contact slowed down and pulled over. The engine warning light was illuminated. The vehicle was taken to the local dealer and was diagnosed with a detached valve. The vehicle was repaired under an extended warranty. The dealer informed the contact that the failure might recur. The failure mileage was approximately 12,998.

Filed Sep 9, 2026 · Body, Electrical · GA

A GM warranty engine replacement was performed at Heyward Allen GMC in [XXX] on XXX at 70,415 miles. We purchase the vehicle on XXX with 73,904 miles and after driving for a month started having multiple malfunction indicator lights displaying, and experienced a no start condition. We took the vehicle to the Don Ledford GMC dealer in [XXX], and they performed a high level inspection. They found missing mounting brackets, loose wiring harness wires, broken and missing bolts. Issues all related to an engine replacement procedure. Deeming the vehicle unsafe to operate. The origin dealer that was paid through GMC to replace the engine is now refusing any responsibility for resolving these issues. Technicians have video evidence of the workmanship issues, documenting the sub- par repair work performed during the engine change. The vehicle now sits at the Don Ledford GMC dealer awaiting an estimated $4400 repair, before the vehicle is safe to operate on the road. The vehicle has been at the Don ledford dealer since XXX, and is still there today, XXX. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

Filed Sep 1, 2026 · Engine, Fuel system · CA

I am reaching out to the federal safety agency due to a vehicle that I believe will get me and/or my family in a major accident and cause serious injury or death. The vehicle that I had purchased in 07/08/2025 had a clean history report and was bought at 54,587 miles. It started having issues 8,563 miles later (odometer reading 63,150 ) on a trip that was 400 miles round trip. I was driving the vehicle on a highway at 65 mph and i felt a knocking vibration in the pedal it was not long before i could even pull over when the engine throttle had completely lost power causing the vehicle to almost come to a complete stop immediately having to steer onto the shoulder. after failing with no check engine light or warning present during the use of the vehicle on the road. it was giving off high temp/engine overheating with the engine making a continuous knocking sound in the engine. It eventually seized to work completely not being able to shift into neutral to push, and had to get it towed to the dealership 204 miles away. GM had advised the dealership to replace the whole engine which they did, and that second engine had given out 678 miles later (odometer reading 63,828.) I am now on my THIRD engine and i cannot trust or rely this vehicle for saftey or transporation. i have reached out to GM to file a claim and attempt to adress this issue to try and come to a resolution, however they denied my claim and have said that i am not "eligible" for a buyback program. I am considering getting legal attorney this is very frustrating to say the least GM is a terrible manufacturer for this issue

Filed Aug 26, 2026 · Engine · NC

Complete engine failure. Safety is was put at risk one engine lost propulsion on a bridge with no median. Truck towed to a GM dealer that inspected it and replace the engine. Check engine light and low oil pressure light came on approximately 30 seconds before the engine died.

Filed Aug 25, 2026 · Engine · 29,000 miles · MI

The contact owns a 2023 GMC Sierra 1500. The contact stated that while driving approximately 40 MPH, the check engine warning light illuminated, and an oil message was displayed. The vehicle stalled and was unable to be restarted. The vehicle was towed to a dealer where it was diagnosed and determined that the engine needed to be replaced. The vehicle was repaired, but the failure reoccurred approximately two weeks later. The vehicle was taken to a different dealer but was not yet diagnosed. The manufacturer was notified of the failure. The failure mileage was 29,000.

Filed Aug 19, 2026 · Brakes, Transmission · OH

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 the federal safety agency 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