Owner-reported complaints naming the powertrain system, filed with NHTSA
Data refreshed
Powertrain reports that are not specifically the engine or transmission — driveshafts, axles, transfer cases and differentials. Every record below is an owner-reported complaint about the 2015 GMC Sierra 1500 submitted to NHTSA — not a confirmed defect, not a recall and not a manufacturer bulletin. 95 reports on file name it.
Complaints are reports submitted by owners and drivers to NHTSA. They are not verified and do not establish that a defect exists.
The 25 most recent of 95, in the owner's own words
My 2015 GMC Sierra 1500 SLE has the 6L80 transmission. While traveling on the interstate with my fiancé, the transmission failed. It was towed to a garage and they informed me that it needed to be replaced.
For no apparent reason the truck goes into “low power mode” and gives off code p2138 often happens around 30-35 mph. Have had it happen to me also around 45 mph also. I have replaced sensors and parts to which a month or so goes by and it happens again.
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
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.
The temperature sensor in the transmission is faulty leading to hard/delayed shifting, shuttering, and vibration
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.
Push rod failure in #4 cylinder at 104,000 miles. Bent push rod. Possibly due to AFM.
I have owned 4 of these trucks in my lifetime ranging from 2007-2015 all equipped with the same drivetrain. 5.3l engine and 6l80 transmissions. All have had the same failures. The engine afm system particularly the lifters fail which in turn destroys the camshaft and destroys the engine. More importantly the transmission torque converter fails sending debris through the whole system causing a sudden loss of drive. This happened while driving down the road and was a safety concern for myself and others. This time it costed me $6500 to replace the transmission. All of the trucks I have owned experianced the same failures how is this not a problem?
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.
I am reporting a critical issue with the transmission. The transmission frequently slips, hesitates, and jerks unexpectedly during acceleration and gear shifts. On multiple occasions, the vehicle has lost power or failed to respond while entering intersections, merging onto highways, or attempting to accelerate—posing a serious safety risk. The issue often occurs without warning and has worsened over time. Additionally, there are instances of harsh downshifting, delayed engagement from park to drive, and sudden lurching forward or backward, which could easily result in a collision. Despite visits to the dealership and complaints made, the issue has not been resolved, and I’ve learned that many other owners of this same model have reported nearly identical symptoms. This appears to be a systemic problem with the transmission system. Given the safety risk, especially in traffic and at high speeds, I strongly believe this defect warrants immediate investigation and a formal recall.
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
Motor blew up while driving down the road. Had to replace motor on 08/23/2023 at about 116,000 miles. Left me and my family stranded in the middle of no where. Was going around 60 miles an hour and when passing someone got up to 71 mph and then motor blown push rod bent. Transmission issues. Hesitation when switching from park to drive/ reverse. Takes at least 40 seconds and when you accelerate it will jerk so hard. Will lunge forward very sudden and sometimes even when coming to a stop at a stop sign. This happens almost every day.
In the fall of 2023 my 6.2L V8 with only 107,565 well maintained Miles completely seized up and shut off without any warning lights or other indications of failure. I was going up a steep hill and luckily I was able to get to the side of the road by coasting backwards to a stop and fortunately no one else behind me at the time. I did not get my truck back until late spring of 2024. I paid over $13k out of pocket to replace the engine because of this issue that is known to many other GM truck owners. Prior to catastrophic engine failure I’ve had multiple services including replacement of torque converters which would cause the truck to shake violently when shifting along with violent shifts in the 8 speed transmission and at times the feeling of being rear ended when slowing down or coming to a stop which GM claims to be “normal operation”. The engine failure was never investigated by any other parties but was looked at by the dealership service department. Both violent shifts and torque converter shutter were also confirmed by the dealer but only fixed with what I consider to be temporary remedies.
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.
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.
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 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.
It keep having this issue constantly every minute saying trailer brake system
Had two lifters collapse and fail. Replaced transmission twice due to torque converter failure
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
Higher-selling and older vehicles accumulate more reports. Counts are not failure rates and are not directly comparable between vehicles that sold in very different numbers.
Categories with enough reports to have a page of their own
Data on this page last refreshed .