2025 GMC Yukon

Purchased new August 29, 2025 On 12/3/25- Mileage 4495. Took vehicle in for first maintenance service. Tire rotation and oil change. On 1/7/26- Reported grinding noise we had began noticing when starting vehicle. Engine light Service ESC. Service Traction control. Reported to Ben Mynatt GM. On 1/8/26 Mileage 7120- Took Yukon in for service due to grinding noise. Due for 6 module updates and 3 stand alone updates. On 2/16/26 Noticed ticking noise when heat in on high. Scheduled service for 2/26. On 2/24/26 Smell from car, oil reporting low. Dip stick completely dry. Sent email and photos to Ben Mynatt Service. On 2/26/26 Took vehicle in for service. Service advised to start oil consumption test. Ordered blower motor for the squealing noise. Cyl 3 misfire. Was told by the dealer, possibly needs engine 2/27/26 Took Vehicle in for service Check engine light on. Bearing inside blower motor and blower motor replaced. Replaced coil cyl 3 Tire Rotation 2/28/26 Car shaking, smoking, engine light on. Terrible smell from exhaust. Engine light came on, Service ESC, Service Traction Control, Forward Collision Unavailable, Reduced Acceleration Drive with Care Alert. GMC Alert: Service the engine and transmission system immediately alert, Engine Light on. Vehicle Approx miles. Codes misfires to cylinder 3. Took vehicle right to Service Dept. Codes Cleared. Replaced coil on cyl 3 March 7th - Mileage 11,200 Car shaking vigorously! Engine light flashing. Loud knocking coming from vehicle. GMC alert: Service the engine and transmission system immediately alert. Emission system- service now. Engine and Transmission System Service now. Service antilock braking, Stabilitrack stability control systems and airbag system. Service Air Bag System. Emailed to Service March 9th. Took vehicle in. Cylinder 3 & 8 misfire code cold start rough idle code. Oil consumption using approx1 qt of oil/500 miles. Vehicle unsafe risk of engine seizure, fire risk and loss of acceleration is extreme danger

While driving on a highway, the vehicle intermittently experienced a sudden loss of engine power during acceleration, accompanied by a flashing check engine warning light. The most serious event occurred while merging into traffic, when the vehicle failed to accelerate normally and briefly lost power, creating a risk of being struck by faster-moving vehicles. After pulling over and restarting the vehicle, normal acceleration temporarily returned, but the problem has recurred multiple times. The malfunction appears to be related to an engine misfire or powertrain fault because the check engine light flashes during the events and an OBD scan has shown misfire-related diagnostic codes (random/multiple misfire and a cylinder-specific misfire). The condition is intermittent and typically occurs after the vehicle has been driven for approximately 10–45 minutes. The vehicle remains available for inspection. The vehicle has been presented to authorized service departments multiple times for diagnosis. The dealerships have reported that they were unable to duplicate the issue during road testing and no lasting repair has been completed. The manufacturer has been contacted and the vehicle has been inspected/diagnosed through authorized service channels, but the underlying cause has not been identified. The failure continues to occur intermittently and is a safety hazard because it affects acceleration in traffic. Incident list 10/25/2025 (~12:25 PM; ~3,108 miles) — While accelerating to merge onto a highway, the vehicle lost power and the check engine light flashed. The driver pulled over, shut the vehicle off, restarted, and the condition temporarily resolved, allowing the trip to continue. 10/27/2025–11/04/2025 — The same loss-of-power/misfire behavior recurred intermittently, typically lasting a few minutes before clearing. 11/05/2025 (~8:01 AM; ~3,641 miles) — The check engine light flashed again and symptoms consistent with misfire/loss of power were present. The

After less than 2000 miles, the OnStar module failed, which removed the capability for emergency assistance, GPS, advanced cruise control, etc. The part is on back order with no ETA, and it appears, based on my research, that this is a common problem with GM vehicles for the past several years. Not having the emergency assistance phone system available is an extreme safety issue, as there are many areas of the US that do not have adequate cell coverage to get assistance in an emergency. It seems as though GMC does not care.

The console screen that control many vehicle functions will often not boot up when the vehicle is started. Screen crashes have also happened while underway. The screen will be unresponsive to both touch and physical controls. Systems unable to be controlled include safety cameras and sensors, climate control, navigation, gauges, infotainment and others. I have attached a diary of specific issues and work arounds attempted. The dealership and GM do not appear to have methods of fixing the issue at this time.

In heads up display i was driving down at 74 mph in cruise control with nobody around or in front to cause the vehicle to suddenly come to a complete stop by its self, I had to hit the accelerator so we wouldn't get rear ended. Then when we got home I was backing in my driveway and the automatic brakes locked up stopping me from backing up.