2015 GMC Sierra 1500 Power Train

The contact owns a 2015 GMC Sierra 1500. The contact stated that while at a complete stop and attempting to shift into reverse(R), Drive(D) or park(P), the gear shifter was stuck, and the contact had to go underneath the vehicle to move the shifter cable into the intended gear. The vehicle was taken to an independent mechanic, where the upper and lower shifter cables were replaced. The contact stated that upon returning to the residence and attempting to park the vehicle, the gear shifter failed to remain in the intended gear and was moving unintendedly. The vehicle was not repaired. The dealer and the manufacturer were not contacted. The failure mileage was approximately 225,740.

During day to day driving when the truck is accelerating from a stopped position there's a massive clunk or hard shift from either 1st to 2nd gear. have also heard similar complaints from other 2015 sierra 1500 owners saying the transmission is having a hard shift on acceleration from a stop. Have seen possible issues with the TCCM

Tranmission is shuttering and not wanting to shift right

Transmission failed at 110k miles roughly. Safety was put at risk due to this happening on a highway. Yes, transmissiom was replaced by a local repair shop, the means of failure was identical to thousands of vehicles in this model year failing prematurely. No it wasnt inspected by the dealer. No there was no warning light, we were going up a hill and it failed.

I am writing to formally submit a serious safety complaint regarding the transmission in my vehicle, which nearly caused a life-threatening accident while driving under normal conditions. While traveling on a two-lane rural highway, I was attempting to climb a steep hill when the transmission suddenly began to slip. My vehicle lost power mid-ascent, despite steady pressure on the gas pedal. The RPMs shot up erratically, but the vehicle failed to accelerate. As I began to crest the hill, the transmission completely disengaged, forcing my vehicle into a free-roll situation. The danger escalated quickly. As I started to descend the hill, I attempted to downshift to control my speed—but the transmission would not respond. It slipped again, and I was essentially coasting with no engine braking. An 18-wheeler was behind me, approaching fast. I could see it barreling toward me in my rearview mirror, and I had nowhere to go. With the road shoulder too narrow and no pull-off in sight, I had to veer dangerously close to the edge to avoid being rear-ended. I truly believe that if the driver of the semi hadn’t taken evasive action, I would not be here to write this complaint today. This transmission failure is not only unacceptable—it is a critical safety issue. A vehicle should not lose all power and braking control during normal highway driving. This is not just an inconvenience or a performance issue. This is a defect that puts lives at risk. I am requesting that this transmission be investigated for an official recall. I have since learned that I am not the only one experiencing these symptoms, and it is only a matter of time before this defect causes a fatal accident. Please take immediate action to investigate this issue. I am willing to provide full documentation, diagnostic reports, and be available for further interviews if needed. Lives depend on it.

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.

Push rod failure in #4 cylinder at 104,000 miles. Bent push rod. Possibly due to AFM.

A valve spring broke while going around 40 mph. Was not accelerating when it happened. Destroyed the piston, head and cracked the block. Once apart found the AFM lifter had started to wipe a lobe on the cam. Engine shut off after running real rough luckily my son was able to pull over. Truck had regular service and taken good care of. My favorite truck I have ever had. Had 137,000 miles on the odometer. This could have ended badly.

The contact owns a 2015 GMC Sierra 1500. The contact stated while driving at an undisclosed speed, the transmission was difficult to shift into gear, with the check engine warning light illuminated. The vehicle was taken to an independent mechanic but was not diagnosed or repaired. The dealer was contacted. The vehicle was not diagnosed or repaired. The manufacturer was not made aware of the failure. The failure mileage was approximately 144,000.

I believe the torque converter failed and resulted in the transmission starting to fail. It still goes down the road but shudders when slowly gaining speed

The contact owns a 2015 GMC Sierra 1500. The contact stated while driving 30-35 MPH in third and fourth gears, the vehicle vibrated and shuddered significantly. The check engine warning light was illuminated. The contact stated that upon shifting out of third and fourth gear, the vehicle responded as needed. The contact stated that the failure progressively worsened while driving in third and fourth gear. The vehicle was taken to Wyatt's Automotive Repair, where it was diagnosed with transmission failure. The contact was informed that the transmission needed to be replaced. The vehicle was repaired. The dealer and the manufacturer were not notified of the failure. The failure mileage was approximately 97,000.

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.

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.

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.

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.

The contact owns a 2015 GMC Sierra 1500 Denali. The contact stated that while shifting the vehicle from park(P) to drive(D), the vehicle hesitated and then jerked into gear. The contact stated that the entire vehicle was shaking when it jerked into gear. The contact stated that the failure was also occurred while shifting the vehicle into reverse(R). Additionally, the failure occurred while slowing down for a traffic signal. The contact stated that the failure was a constant. The contact stated she had not noticed any warning lights during the failure. The contact had taken the vehicle to a local dealer who advised the contact that there were no open recalls for the transmission on the VIN. The vehicle was not diagnosed. The vehicle was not repaired. The manufacturer was not informed of the failure. The failure mileage was unknown.

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.

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.

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.

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.

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

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).

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.

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.

The transmission has a HORRIBLE VIBRATION when driving. Either going slow or fast.