2015 GMC Yukon: check engine light

Filed Sep 22, 2026 · Engine · WA

The vehicle developed a recurring cylinder #4 misfire with a flashing check-engine light, rough running, and reduced performance. Diagnostic code P0304 repeatedly returned. Replacing the #4 spark plug temporarily restored normal operation, but the misfire returned after a few hundred miles. The #4 plug was wet/oily, and fresh oil was found pooled in the #4 intake port while the other ports were dry. All eight spark plugs, ignition coils, and plug wires were replaced, along with the #4 fuel injector and both #4 valve-stem seals, but the misfire persisted. A valvetrain/lifter tick later became audible near 3,000 RPM. The failure has now been confirmed as a valvetrain failure that severely damaged/destroyed cylinder #4 and requires complete engine replacement. The vehicle is available for inspection upon request. This defect creates a serious risk of severe misfire, loss of engine performance, or complete engine failure while driving.

Filed Jun 11, 2025 · Brakes, Lights · 195,846 miles · LA

The contact owns a 2015 GMC Yukon. The contact stated that while depressing the brake pedal, added pressure was needed before the vehicle came to a stop. The contact stated that the vehicle hesitated or jumped before coming to a stop. Additionally, the contact stated the transmission was slipping. The contact stated that while driving at various speeds, the vehicle stalled before self-correcting. The contact also stated that while idling at a stop light and attempting to accelerate, the vehicle hesitated, but gradually accelerated as needed. The contact stated that the rear taillight intermittently failed to illuminate. The contact stated that the check engine warning light was illuminated. The transmission fluid was flushed; however, the failure recurred. The vehicle was taken to the dealer who diagnosed the vehicle and determined that the transmission was fractured, and the light bulbs needed to be replaced. The transmission was not repaired or replaced. The headlights were not replaced. The dealer confirmed that the brakes were included in the federal safety agency Campaign Number 19V645000 (Service Brake, Hydraulic) and the vehicle was repaired; however, the failure persisted. The vehicle was driven to the residence without further repairs. The contact stated that the vehicle had become inoperable. The manufacturer was not informed of the failure. The failure mileage was approximately 195,846.

Filed Sep 11, 2024 · Lights, Transmission · TX

My vehicle is currently in the shop getting the motor worked on for a bad lifter. From the information the mechanic provided me this is a common issue with the vehicles that have the Active Fuel Management system. They are seeing many of these vehicles have to come in and have very expensive repairs. My first quote I received was $16, 000, they told me I needed a whole new motor and this assessment cost me $365 and a rental car while they looked at the truck. Now it is in the shop again and the estimate is $6000 to machine the cams as there are metal shavings in my oil. I had to again rent a rental vehicle and have not had my truck for a week. This is the third mechanic that has seen multiple of these motors have to be replaced or repaired due to this issue. I kept up on my oil changes and other recommended car maintenance and so did the owner before me. I had my last oil change approx. a week before the loud ticking noise began, then my vehicle began to have a noticeable loss of power when driving and eventually began shuttering and my check engine light began to blink and I took it to the shop. A year ago I had to replace my tail lights. I was able to find where others were recalled by my VIN for some reason was not included in the recall. They started shorting out and working only part of the time which is very dangerous when stopping, especially at night. I had them replaced and paid almost $700 for the two back lights.

Filed Jun 25, 2021 · Engine · 120,058 miles · MI

The contact owns a 2015 GMC Yukon. The contact stated that while driving approximately 25 mph, the check engine warning light illuminated, and the vehicle started to vibrate abnormally. The contact had taken the vehicle to the dealer who diagnosed that the catalytic converter needed to be replaced. The vehicle had not been repaired. The manufacturer was not made aware of the issue. The approximate failure mileage was 120,058.

Filed Jun 21, 2021 · Suspension, Transmission · NC

At certain speeds my vehicle vibrates, like a grinding sound at speeds between 50-55. This is a safety risk because I have children and grandchild that frequently ride with me. I have taken my vehicle back to the dealership and they say it is no codes and send it back to me without fixing the problem. My vehicle has not been inspected by anyone except the GM dealership. I got my vehicle Nov. 2018 and this started happening between Dec. 2018 and Jan. 2019. My check engine light did appear and was flashing around this time. In 2019 I had to replace the rear shocks and I believe they are not working properly now.

Filed Sep 16, 2020 · Engine · 165,000 miles · GA

When sitting at a light, or stop sign vehicle acts as if it wants to cut off, check engine light is flashing, when I'm driving vehicle the check engine light stays lit. I did a scan of the vehicle and the code I got was p0303 which is for a cylinder 3 misfire. I have changed out the spark plugs and wires, also the ignition coil. I changed out the fuel injector for cylinder 3 and also the fuel pump actuator. Its still shaking, don't know what the problem is but I hope you guys can come up with what I need to do next. I've had to spend money out of pocket for this because its not under warranty.

Filed May 18, 2020 · Fuel system · 90,000 miles · IN

Was driving down the road and suddenly the check engine light started flashing and the esp light came on. I was very close to home so I drove back home and as I stopped the car it started shaking and I turned it off. Brought it to the mechanic and he said the fuel injectors need to be replaced. I have been without my car for 11 days now as this is such a common problem that all the parts are on back order. This is very dangerous and needs to be recalled especially as it is such a common problem. For such an expensive car these kinds of things should not be happening. Hoping for a recall soon so that I can receive my money back.

Filed Jul 16, 2015 · Engine · 7,785 miles · FL

When the car is at idle in drive it becomes very rough (fluctuates up and down). This happens on and off and I have no check engine light on. Sometimes the car even feels like it is going to stall out. I have had it into the dealer and they admitted they feel it as well. They tried adjusting the motor mounts and that did not do it. After having in the dealer for several days they called me and said they can't find the issue. They told me they went into another 2015 gmc yukon sle and started feeling the same issue. It was stated to me I might have to wait for more complaints on the vehicle to get to the root of the issue. It continues to idle roughly and I want to get this resolved.