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.
2015 GMC Sierra 1500: complete transmission failure
18 of the 721 complaints about the 2015 GMC Sierra 1500 describe complete transmission failure.
- owner complaints
- 18
- of this car's complaints
- 2%
- typical repair cost reported
- $4,400
- typical mileage
- 97,000
- recalls
- 0
Complete transmission failure by model year
What owners say
This occurred 5+ years ago. Coming home one night I had a sudden loss of power with the truck and barely made it home. Was able to limp the truck to the dealership the next day and was told that one side of the engines lifters had failed. Prior to the failure I had noticed a ticking sound coming from the engine that was becoming increasingly more prominent. It was several thousand dollars to repair. Fortunately the failure occurred near home, not on the freeway where I could have been dodging cars while trying to limp the truck to the shoulder. Some online research while the repair was being done revealed that several other owners with the 6.2L engine had the same problem. When I mentioned it to the dealer the response was that they had no bulletins from GM on the issue and I was stuck with the bill. Got the same response a year or two later when the torque converter on the transmission went out. The reason I am reporting it now is I saw that GM is recalling 6.2L vehicles with lifter issues but not back to 2015 even though the issue appears to go back farther than that. They claim it's limited to a specific run of engines for the recall. They have been having various lifter problems for many years that have put drivers in danger when they fail but refuse to acknowledge it. As for the repair they made to the engine I've driven another 70 K miles and the ticking has started again. I fear another failure. Please note that the date previously given for the incident is my best guess.
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 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.
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.
Had two lifters collapse and fail. Replaced transmission twice due to torque converter failure
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.
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.
Service bulletins that may apply
- Power train
- This service bulletin provides information on Transmission Adaptive Functions and Correcting Low Mileage...
- Power train
- This service bulletin provides information on the harmful effects of ethylene glycol in transmission fluid.
- This service bulletin provides information on some vehicles that may rock or move slightly forward or...
- Power train
- Power train
- Power train
Related recalls
No recalls on record for this model year.
Questions about the 2015 GMC Sierra 1500 transmission failure
Is complete transmission failure a common problem on the 2015 GMC Sierra 1500?
18 of 721 owner complaints about the 2015 GMC Sierra 1500 (2%) mention complete transmission failure. The model year with the most reports is 2017.
How much does it cost to fix complete transmission failure on the 2015 GMC Sierra 1500?
Owners who mentioned a price put the repair at about $4,400 (median of 5 complaints that include a dollar amount). Costs vary with mileage, warranty and where the work is done.
Is there a recall or service bulletin for this on the 2015 GMC Sierra 1500?
There are 0 recalls and 136 service bulletins for the same area of the car. Check them below with your VIN.
Other symptoms on the 2015 GMC Sierra 1500
Headlights 89Brake failure 35Loss of power 32Check engine light 21Power steering loss 21Spongy pedal 19Stalling 18Harsh shifting 17Shudder 15Engine failure 14Jerking 14Fire or smoke 13Hesitation 12ABS 11Knocking 11Slipping 11Misfire 7No deployment 6Steering lock-up 6
VIN decoder
See the problems and recalls for an exact car
Buying a used 2015 GMC Sierra 1500?
Check the exact car before you pay: accidents, salvage or flood titles, odometer readings and previous owners.
Check its history