2025 GMC Sierra 1500: check engine light

Filed Oct 19, 2026 · Engine · MI

In April 2025, we purchased a new GMC Denali Sierra 1500 Ultimate pickup truck. Concerns – Many of these comments appear in the Dealer Service Reports 1st Service Visit 10/17/25 At our first oil change and scheduled maintenance (10/17/25) with mileage of 5403 miles, during the drop-off I informed the GM Service Advisor of a clicking sound from the engine which I thought might be a fan belt. When I picked up the truck from Service, the Service Adviser informed me that upon startup, a “clatter” type noise was heard, “reminiscent of bad lifters.” The Service Adviser reported that during the mechanic’s test drive, the “clicking noise would get louder with engine speed.” No trouble codes were found after being checked by the MDI. They checked for misfires and a few misfires were found but “not often. At “idle” during this service call, the Left Engine Bank had a “good click/metallic tap to it.” “When the idle was raised, the Right Bank would get loud and had a loud tapping sound.” The oil change did not show any visible metal particles. The GM Service Department recommended a “complete tear-down of the engine for further inspection,” tentatively scheduled in a few weeks, pending Service availability. The Service Adviser stated he would recommend an engine replacement. 2nd Service Visit 10/27/2025 While driving the truck, I noticed that the engine “ticking” had gotten louder, and a Check Engine light had gone on and off. I returned to the Service Department on 10/27/25 (mileage 5807). The Service Department inspected the vehicle and found no “stored DCTS” but found “noise is there for internal engine noise.” The team recommended “tear-down or possible new engine.” Service appointment was set for 11/3/2025 for 5-days. 3rd Service Visit 11/3-7/2025 Service department reported that there were no problems. Vehicle was not under recall..... Scheduling a oil change this week. 14,500 miles.

Filed Sep 17, 2026 · Electrical, Engine · 34,637 miles · MO

The contact owns a 2025 GMC Sierra 1500. The contact stated that while driving approximately 5 - 10 MPH, the vehicle went into LIMP Mode and failed to properly accelerate, and the transmission unexpectedly downshifted. There was an electrical malfunction, which caused the transmission to downshift. An unknown message was displayed on the instrument panel. The contact stated that the network was not operating at the correct voltage due to the wiring harness. The engine light illuminated after the failure. The vehicle was towed on two occasions to the dealer to attempt to duplicate the failure. The dealer was unable to determine how to repair the vehicle. The vehicle was driven to the dealer in LIMP Mode. The manufacturer, General Motors, was contacted by the dealer, and the contact also reported the failure to the manufacturer. A General Motors service engineer had inspected the vehicle. The failure mileage was approximately 34,637.

Filed Sep 8, 2026 · Engine · PA

On XXX my 2025 gmc sierra 6.2L v8 engine experience catastrophic engine failure with no preexisting alerts or warnings. It was towed to Baglier gmc in [XXX] on XXX and is currently awaiting diagnostic evaluation. Upon restarting the vehicle after failure, the engine light did turn on. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

Filed Aug 28, 2026 · Acceleration, Engine · LA

I own a 2025 GMC Sierra 1500 Denali equipped with the 6.2L V8 L87 engine, VIN [XXX]. The vehicle had approximately 35,000 miles when the engine experienced a catastrophic engine failure. Prior to/during the failure, the vehicle experienced abnormal engine noise and a loss of power. Multiple warning/alarm lights appeared on the dashboard, including the Check Engine and Traction Control warning lights. The engine failure resulted in a loss of motive power and made the vehicle unsafe to operate. PHONE# [XXX] The sudden loss of engine power while driving created a serious safety hazard because the vehicle could no longer operate normally in traffic and could potentially cause a crash. I am requesting that the federal safety agency document and investigate this engine failure as a potential safety defect involving the GM 6.2L L87 engine. I am also requesting that the federal safety agency determine whether 2025 GMC Sierra 1500 vehicles equipped with this engine should be included in an appropriate safety recall or other corrective action. The vehicle is a 2025 GMC Sierra 1500 Denali with approximately 35,000 miles. The engine failure and warning lights occurred during normal vehicle operation. The vehicle and repair records can be made available for inspection, and I can provide dealer repair orders, diagnostic information, photographs, and other documentation concerning the failure. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

Filed Aug 21, 2026 · Engine, Transmission · FL

On July 25, 2026 when starting my vehicle, it began to shake violently and I receive numerous errors, including a check engine light and displays in the infotainment, indicating there were engine and transmission errors with the vehicle. I received a text message notification and in app notification from GMC indicating that there was a critical error and provided error code P0352. This appears to be an error related to a faulty engine, this is the 6.2L V8, which is known to be problematic by GMC. Had this happened while I was driving on the interstate three minutes later, it could’ve resulted in great bodily harm or death to both myself and the general public around me. GMC was later able to reproduce the issue at the dealer, confirming the faulty equipment on the vehicle with less than 16,000 miles on it. The component was replaced by the dealer, however, the vehicle is available for inspection.

Filed Jun 6, 2026 · Engine, Transmission · MT

Rough idle started at 11,400 miles. Took to GMC dealer near me and had thrust bearing clearance measured. Measured .0054"(within spec). They released truck back to me. 19,400 mile oil change found large metal(non magnetic) slivers in the filter media. I cut filters to check for issues due to known issues with this engine(metal). I called gmc corporate, i was told to not drive the truck. I paid out of pocket for the tow 142 miles away. Dealer told me they checked thrust bearing and came in at .0055", no noises, and no check engine light. Idle is very rough on start up. GM corporate stated a service advisor will call. Never got a call. I have sent and displayed the evidence and offered to show oil filter contents to both dealer and corporaten both have not done anything about this safety issue. This is a SEVERE safety issue. Engine is highly likely to lock up and cause serious injury to both me, my family, and others on the road. Dealer has released truck back to me and my family with clean bill stating they didnt find anything wrong. They refused to see my documentation of metal slivers or the 3 rimg binder full of maintenance records. As of now i will be escalating this to higher up in GMC corporate. SEVERE safety risk for my family and everyone on the road. GMC dealers refusing to diagnose.

Filed May 28, 2026 · Engine, Transmission · IL

In normal operation on Tuesday May 26,2026, the engine experienced catastrophic failure. The engine is the GM L87 6.2 Liter. This was on a highway in the country and I was able to maneuver the truck off the road before an accident occurred. It did leave me stranded and I was required to get it towed on a roll off (It was not drivable) to the dealer where I purchased it. The dealer [XXX] ) inspected my truck and has informed me that the issues with my 2025 Sierra match the issues for the recall GM had for the model years 2021-2025. It will require a new engine, radiator, among many other parts. There weren't any previous warnings. A check engine light only came on once the engine was engine came apart. An oil change on the vehicle by GM was done a month ago. The truck is a 2025 and has approximately 6,600 miles is all. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

Filed May 15, 2026 · Engine · GA

My GMC sierra AT4 with the 3.0L Duramax Diesel, has 1,500 miles on it, when the engine failed. I was traveling from [XXX] to [XXX] , towing a trailer, when the check engine light came, and the truck entered reduced power mode. It immediately slowed the truck without warning - which made for a very dangerous situation for all of the vehicles behind me and for my vehicle. After getting the vehicle and trailer to a dealer, disconnecting the trailer, and then getting the truck in the shop, the dealer defined the OBDII code as being P06DD - Engine oil pressure control solenoid valve stuck off. U0146 - Lost communication with central gateway module, and U1605 - Lost communication with side obstacle detection control module - right on private CAN Bus. The dealer indicated that the P06DD code meant that the thrust bearing on the crankshaft failed and the engine would need to be replaced. The ending only has 1500 miles on it. It turns out that there are MANY GM 3.0L diesel engines that have failed for this issue and that GM issued a Technical Service bulletin in 2025 for this issue - TSB 25-NA-307. I work in the medical device industry and when there is a safety issue with your products - you initiate a RECALL. To date there has been no recall simply the TSB. What is the federal safety agency going to do about ensuring that GM, and other manufacturers, are making engines safe? These engines can literally explode - sending metal shards through the engine into the passenger compartment. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

Filed Jul 24, 2025 · Electrical, Fuel system · MA

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.

Filed Jul 24, 2025 · Brakes, Engine · MA

While in the parking lot of a local grocery store, I shifted the vehicle into reverse, at which point all dashboard warning lights immediately illuminated and the braking response became significantly weakened and nearly unresponsive. I placed the vehicle back into park, paused, and then attempted to shift into reverse again, but the dashboard alerts and brake issue persisted. This created a very unsafe driving situation because the brake system was very unresponsive. Despite the unsafe condition, I cautiously drove to my home 2miles away at a speed of under 20 MPH, requiring excessive brake pressure to bring the vehicle to a stop. I parked the vehicle in my driveway and left it there overnight. The next morning, I tested the brakes, and they seemed to return to normal so I drove 5 miles to my local GMC service center. Service Tech confirmed Check Engine Light On and reported code P0700 and P00FF in the report.

Filed Jul 16, 2025 · Electrical, Fuel system · MA

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.

Filed Jan 14, 2025 · Engine, Steering · ID

While on the freeway at 65mph the truck experience a hard gear shift, loss of acceleration, went into shut down, lost steering assist, and brakes became hard, lights came on the dash for transmission issue massage, as well as Check engine light. Safety became a major concern with loss of power in the mids of a flow off traffic at freeway speeds. Vehicle had to be towed.