The contact owns a 2015 GMC Sierra 1500. The contact stated that while driving at an undisclosed speed, the transmission unexpectedly downshifted with no warning light illuminated. The vehicle was taken to the dealer where it was diagnosed with transmission failure. The contact was informed that the transmission needed to be replaced. The vehicle was repaired; however, the failure reoccurred. The manufacturer was not made aware of the failure. The approximate failure mileage was 147,000.

- Houston, TX, USA

I've been having transmission issues which cause harder shifting than usual. upon research, I found that the 2016 GMC Sierra's have a special coverage that replaced the transmission harness which throws the code P0711 for the temperature sensor and P0700 which is the generic transmission code. The only difference between my VIN and the VINs covered under this special coverage is that my Sierra is a 2015, everything else is the same down to the part number of the known faulty transmission harness.

- Bear, DE, USA

On 12/11/24 I had exited I95N, While traveling down the exit ramp I felt my truck buck, upon the light changing I went to accelerate and the truck transmission slipped and barely got into first gear. I again came to another traffic light and the transmission did the same thing. I put my hazard lights on and shifted through all the gears and finally I was able to get the truck moving. The following morning I brought the truck to my local mechanic and I was told I needed a new transmission, which is going to cost me $4400. About a year prior my daughter had a similar problem with her 2018 Chevy Silverado in which she had to replace the transmission valve body. With both of these occurrences the truck gives you no warnings and just stops driving and causes a real threat to safety.

- Coral Springs, FL, USA

The contact owns a 2015 GMC Sierra 1500. The contact stated that while depressing the accelerator pedal, the RPM's increased; however, the vehicle failed to properly accelerate. During the failure the trailer hitch and 4WD messages were displayed. The cause of the failure was not yet determined. The local dealer and manufacturer were notified of the failure, but no assistance was offered. The failure mileage was 119,453.

- West Haven, CT, USA

The contact owns a 2015 GMC Sierra 1500. The contact stated that the vehicle shuddered upon depression of the accelerator pedal, there was no warning light illuminated. Upon investigation, the contact determined that the failure was likely caused by the torque converter. The dealer was contacted about the failure and informed the contact to take the vehicle for an inspection. The contact took the vehicle to an independent mechanic where the torque converter was flushed, and the transmission filter was replaced. Despite the repair, the contact stated that the failure worsened soon after the repair. The vehicle was taken back to the independent mechanic where the vehicle remained. The manufacturer was notified of the failure and referred the contact to the NHTSA Hotline to file a complaint. The vehicle was not repaired. The failure mileage was approximately 140,000.

- Clute, TX, USA

It keep having this issue constantly every minute saying trailer brake system

- Kansas City , MO, USA

Had two lifters collapse and fail. Replaced transmission twice due to torque converter failure

- Copley, OH, USA

I am on my 4th radiator and 3rd thermostat. August will be 1 year ! 2014 models are covered 2015 (like mine) is not covered. Transmission has shifted like crab since day of purchase 3 years ago. I am told it is a known issue from the factory with no solution. Truck also had a weird tick sense day one which turned into 2 failed valve springs. I have had 2 ball joints FAIL 1st time a month after purchase in my driveway. Second time 2000 miles later same side on my street

- Lusby, MD, USA

The contact owns a 2015 GMC Sierra 1500. The contact stated that while at a stop light and attempting to accelerate, the vehicle jerked and stalled. The vehicle failed to restart and was towed to a dealer and was diagnosed with transmission failure. The vehicle was not repaired. The manufacturer was made aware of the failure. The failure mileage was approximately 88,000.

- Maryland Heights, MO, USA

I purchased my truck (15 GMC Sierra z71 4x4) with around 122,000 miles on it. I would be owner #2. Truck ran great. Around 150,000 miles I noticed my truck's transmission start to jerk while accelerating from gear to gear. No engine light ever appeared. Problem stopped. A few days later while dropping my daughter off at school, my truck wouldn't go passed 35 mph. I had to put the shifter in manual and shift to third gear. Other gears would just rev the rpm's to 4 or 5. Since I didn't want to put my family, me and others on the road at risk. I parked my truck and started driving my other vehicle. A few months went by, and my other vehicle had a flat tire, I had to drive my truck to work. On the way home from work, my truck started acting up again, jerking while accelerating. speedometer would go up however truck didn't move. I had to pull over quickly so I wouldn't be broken down in the traffic lane. I turned the ignition off and waited five minutes and started the truck up. I was able to make it home. At this time the engine soon light came on. I ran my scanner on my truck and code P0700 TCM was the only code showing. I had a Gmc dealer look at my truck and stated I would need a new transmission. I have done many months if not almost close to a year of research with results showing that transmission problems just what I was experiencing are a common problem with 2014-2019 chevy and Gmc / Silverado pickups with transmission 6L80. I dropped my truck off at another transmission shop just yesterday 3/3/24 and the results today were I need a new transmission. Torque converter issues. The shop stated that they repair / rebuild almost three chevy / gmc trucks like my truck a week with the same transmission problem. I still owe on my truck and shouldn't have to pay almost 6K for a transmission that is known to be an issue from the start of factory build. I own many older model gm / chevy vehicles and only had one other issue with one which also had a known recall issue.

- Conowingo, MD, USA

The component or system failed was the transmission 4 different times. A new transmission was put in the car just 6 months after purchasing from a dealer. The transmission lasted close to 3 years being shy only a few days before the transmission warranty expired. So a new transmission was provided by the transmission owner at no additional cost for the transmission but we had to pay $1600 out of pocket for labor. That transmission lasted for 2 months before failing again which caused us to have the truck towed to our home to decide what our next step would be. So we had it towed to Tire max and they put in another transmission by the same manufacturer which we only had 2 days left under the warranty. That transmission failed within 2-3 days so we took it back to a different Tire Max location and they put in another transmission which did not cost anything for us by the manufacturer including labor. This transmission has now been in good standing since 12/20/23.

- Eden, NC, USA

I would like to bring to your attention an alarming incident that occurred on January 3, 2024, with my truck. While accelerating onto the highway, the engine and drivetrain failed suddenly, posing a significant safety risk. The failure left the engine incapable of functioning properly, which could have resulted in a catastrophic accident. Seeking answers about the cause of this dangerous malfunction, I promptly arranged for an inspection by RNZ Concepts. After evaluation, they suspected a potential problem with the hydraulic lifter or camshaft. It is baffling to note that, other than an initial transmission replacement, there were no further indications of any underlying issues, as the truck is regularly serviced. Additionally, within 60 days of purchasing the vehicle, similar issues arose, requiring additional repairs that were paid out-of-pocket at the time. Now, the vehicle is once again out of commission due to persistent GMC failures. The estimated repair cost is expected to be between $6,000 and $10,000.

- San Diego, CA, USA

Vehicle has jerking and feels like you are being hit. scared for my safety. Have taken my my Vehicle to a transmission shop for investigation.

- Camden, SC, USA

The contact owns a 2015 GMC Sierra 1500. The contact stated that there was an abnormal clunking sound coming from the vehicle with the check engine warning light illuminated. The vehicle was taken to Quality Buick GMC, INC. (7901 Lomas Blvd NE, Albuquerque, NM 87110) and Pitre Buick GMC- (9737 Eagle Ranch Rd NW, Albuquerque, NM 87114) and the contact was informed that the failure was related to the transmission and the contact was provided an estimate for the repair. The manufacturer was not notified of the failure. The vehicle was not repaired. The failure mileage was approximately 100,000.

- Rio Rancho, NM, USA

The same part number in the other models are for recall except this model.

- Phoenix, AZ, USA

Transmission was shuddering and slipping and then completely went out. Would not engage any of the gears. This happened while driving through the mountains without towing anything. My family and others on the mountain were at risk since the transmission was slipping out of gear and no safe place to pull over. It had to be towed to a dealer and they confirmed the transmission was toast and they replaced it, of course not under warranty. $800 tow bill and $6.893.98 to replace the transmission at a GM Dealer...Also, had to get a rental car ($318).

- Batavia, IL, USA

Vehicle has a history of hard shifting and jumping forward under certain conditions. In April 2019, while on the highway traveling about 65 mph, the vehicle slipped out of gear and do no longer be driven. No warnings were displayed prior to the incident. The dealer replaced the torque converter and repaired a broken transmission shaft under warranty. Hard shifting and jumping continued to occur, but the vehicle went without incident for another 4 years. Yesterday, 5/8/2023, the transmission went out again while driving around 35 mph. Vehicle is currently at dealer. My research has shown there is a class action lawsuit in 26 States for transmission issues for GMC vehicles between 2015-2019. NHTSA needs to take action and issue a recall. Losing a transmission while driving is dangerous.

- Saint Charles, MO, USA

The contact owns a 2015 GMC Sierra 1500. The contact stated that while shifting from drive (D) to park(P), the contact heard a loud clunking sound. Additionally, while driving and downshifting the contact heard the loud clunking sound. The contact also stated that while driving at an undisclosed speed, the transmission slipped while shifting from 1st to 2nd gear, and the vehicle failed to immediately accelerate. The contact stated that the failure occurred more during the winter months. The vehicle was taken to the local dealer who reprogrammed the TCM however, the failure persisted. The manufacturer was notified of the failure. The failure mileage was approximately 30,000.

- Lansing, IL, USA

My 2015 GMC Sierra SLT with 92K miles was in the shop (3/28/23) for a recall on the brake vacuum pump and they advised me that the oil cooling lines are leaking. They advised me of the potential safety hazard of fire and vehicle damage. There are no warning indications on the dash about this problem. I spoke to a local shop and they advised me to file a report as they have done 2 in the past week. I didn't get it fixed yet as I have a work truck that I drive and this doesn't get driven hardly ever.

- Mannsville, NY, USA

I tried to buy a car at car dealershipin lafayette oregon ( Pouya Auto sales) gmc sierra 2015 black. on the date 02/09/2023. They soldme this car with ABS, cruscontrol, presusre tires ligths on dashbord. the financial bank recomend me to bring the veicule back to the dealership to have them to fixed.. they didnt want to continue with the contract anymore and canseled. now they want to sell the truck to some one else. and is not safe to drive it with this isuuses

- Vancouver , WA, USA