The vehicle is stuck in 4WD hi even though the indicator is set to 2wd. When turning at low speedfs the vehicle applies the rear brakes. The brakes do not apply when driving straight, only when turning at low speeds. It is dangerous when attempting to make turns from stops or parking.

- Atlanta, GA, USA

The contact owns a 2015 GMC Sierra 1500. The contact stated that while driving approximately 35-50 mph, the contact noticed a minor shaking coming from the vehicle. The contact took the vehicle to love Buick GMC (736 Saturn pkwy, columbia, SC 29212; (803) 732-6500) who flushed and refilled the transmission fluid however, the failure recurred. The contact returned the vehicle to the same dealer who performed another transmission flush however, the failure persisted. The contact stated that the vehicle drove rough and that the check engine warning light illuminated. The contact used a dtc scanner and retrieved a code related to the transmission control module and temperature sensor. The vehicle was then taken stokes trainor Chevrolet Cadillac Buick GMC (2004 wilson rd, newberry, SC 29108; (803) 792-4763) and the contact was informed that the internal wiring harness needed to be replaced. The vehicle was not repaired. The manufacturer was made aware of the issue and informed the contact that the VIN was included in a special coverage program. The approximate failure mileage was 75,000.

- New Berrry, SC, USA

While driving the transmission slipped while attempting to change gears. This caused the vehicle to be unresponsive and indicate a problem accelerating. This has been getting worse over the past several months and ended up leaving me in a very dangerous situation yesterday while driving.

- Mountain Home, AR, USA

My 2015 GMC Sierra has the 8 speed transmission which has been an issue since I have owned the vehicle. I bought the vehicle used in the fall of 2018 and the truck/tranny ran good for about 10 months. Then in late summer and early fall of 2019, the truck jerking hard shifts started to appear. In October of 2019 I brought my truck into my dealer to have them look at my tranny due to the really hard shifts from 1st to 2nd or 2nd to 3rd and vice versa 3rd to 2nd and 2nd to 1st. I had to pay a $80 diagnosis fee and they reprogrammed my tranny and the ECU to smooth out the shifts and not make the shifts so hard. In all the software reprogram did get rid of the hard shifts, but in return now my vehicle drove like it has a 6 speed transmission instead of an 8 speed. In June of 2020 I brought my truck back into my dealer to look at my tranny again! now my tranny felt like it was always "hunting" for a different gear. When driving on the interstate at 75 mph 1600 RPM, if there was a little bit of head wind or I started to drive up a hill, the tranny would downshift and RPM's jump up to 2200 RPM to make up for the difference in road grade, same as when driving in town up a hillat 35mph. A 8 speed transmission should not be doing that! at interstate speeds (75 mph) my passenger side seat will sit there and just wiggle and shake back and forth. I have changed out ball joints and struts with brand new ones thinking that was the problem and the seat still wiggles back and forth. When driving my vehicle it feels like I am driving with a 6 speed transmission than an 8 speed. I have read that this seems to be a common problem in these model year GM vehicles and I feel GM needs to finally address this issue once and for all and keep their GM customers satisfied. I didn't plan on buying a 3 year old used vehicle for it to have the issues it has had since I have owned it.

- Sioux City, IA, USA

A few months ago I was accelerating from a stop light the truck suddenly and violently jumped forward it had felt as if I was struck from behind. However no one was there! I did take it to the dealer and they said they could not replicate the condition and no codes were stored. Yesterday this happend once again! I would have sworn some one hit me, the truck shook and jumped forward so hard it felt as if a buss hit me. Once again no one there! I am making this complaint because I see more people are having theses issues and GM calls them "normal" sorry but I have driven trucks for years and have never had one do this! this is a potential hazard because if at any time a car was in front of me I would have most likely hit the car! please fix this issue!

- Denham Springs, LA, USA

Torque converter. Me and along with 4 other people are having problems with it. Upon start up and driving it starts to get sluggish and then just comes almost to a complete stop only building RPM's accrodding to the GM dealership it's normal. With all the GMC trucks I've owned it has never done this. And is only starting to do it over the past couple of months. I've talked to a guy who just had 2 replaced in his truck and is continuing to have the problem. To avoid any vehicle damage for anyone else I'm considering if you can check and see if anyone else is having the issue. I take very good care of my truck I don't mud in it or drive it crazy(wreck less). Dealership is also pretty much refusing to look into the problem or diagnosing it considering that it's 'normal' for the truck do that. Which I strongly disagree.

- Headland, AL, USA

The contact owns a 2015 GMC Sierra 1500. The vehicle failed to shift and remained stuck in gear. Also, while driving various speeds, the vehicle accelerated without warning. The vehicle was taken four times to laroche Chevrolet Buick GMC Cadillac (900 us-290, brenham, tx 77833, (979) 836-6666) where it was diagnosed that the transmission fluid and torque converter needed to be replaced, and reprogramming was needed. The vehicle was repaired, but the failures recurred. The vehicle was taken to mac haik Chevrolet (11711 katy fwy, houston, tx 77079, (281) 497-6600) where it was diagnosed that the vehicle was working as designed. The vehicle was not diagnosed or repaired. The manufacturer was contacted, but did not assist. The failure mileage was 7,000.

- Cat Spring, TX, USA

When putting the truck into gear with the foot firmly on the brakes the truck will slam into gear causing the truck to jump forwards or backwards.

- Braintree, VT, USA

When I'm cruising highway speeds the truck get a violent vibration and makes the vehicle uncomfortable to drive.

- Huntington, IN, USA

Tcc shudder

- Grove City, OH, USA

Transmission shifted hard, delayed acceleration at times, shuddered and jerked. This was usually slowing down to turn around 30 or 40 mph as the truck was in motion. After only two years the entire transmission had to be rebuilt. The transmission was shifting poorly the moment I drove it off the lot even if it "adaptive learning" you could tell there was something wrong.

- Fayetteville, AR, USA

Brake pedal goes soft and can hit the floor on occasion. Mostly happens with in reverse. 40K miles. Also transmission shifts are erratic. RPM can shoot up between shifts.

- Saint Charles, IL, USA

When accelerating truck will sag and or hesitate. When you slow down and try to speed up the truck will hesitate for 5 or more sec. Before speed back up GM said that this is due to zero torque to me this is a safety hazard

- Creedmoor, NC, USA

Loses power when trying to accelerate, presents a problem when trying to maneuver in traffic and semi stalls for.2 seconds enough to cause a delay

- Colorado Springs, CO, USA

Called dealership about one week after purchase in August 2015 and reported vibration in vehicle at speed of 70 and above. No return call. Never had truck inspected. Vibration has increased with age of the truck. Truck has 55,000 miles on it now. Just now finding out about numerous complaints having been filed. Found information at autoguide.com. GM has issued bullet6in #pi1354C relative to this.

- West Monroe, LA, USA

Truck will not change gears and sputtering. Bad gas mileage and not wanting to start.

- Cypress, TX, USA

Steering electrical assist fightback, driving, turning resulting in no steering-deadly! this can happen at any time while driving. Very dangerous! engine must be shut off and restarted before you can get out of street. Then message reads "lower driver window then raise" before proceeding.

- Duncanville, TX, USA

Safety issue: Known issue to GM but company refuses to acknowledge as a safety issue. A large number of GMC/Chevrolet pickups have vibration issue at highway speeds causing stress and unnatural wear on vehicle components which might fail causing a crash at highway speeds. GM dealers unwilling to solve issue on majority of affected vehicles (2014-2015).

- Portage, MI, USA

My truck suffers from vibration problems, the same thing that 10,837 other posts from other people suffering the same problem are talking about on this forum. www.GM-trucks.com/forums/topic/153186-shake-or-vibration-issues/page-723 this forum has been viewed over 1.5 million times which means a ton of people are having this issue. This is absolutely a risk to motor vechicle safety and absolutely exists in a group of vechicles of the same design or manufacture. The problems this shake presents that pose a danger are vibrations so significant that it can cause driver distraction, fatigue on long trips, potential loss of control, not to mention long term health effects from vibration exposure. The health effects defined are as follows: "the effects of whole body vibration (wbv) have been studied extensively in occupational medicine. In particular, it has been shown that when the body undergoes chronically to whole body vibrations spinal degeneration is likely to be one of the deleterious outcomes. Low back pain has been shown to be the leading major cause of industrial disability in the population under the age of 45 years and has been linked to whole body vibration exposure encountered in some industrial settings. Whole body vibration has been recently purposed as an exercise intervention suggesting its effectiveness in increasing force-generating capacity in lower limbs and low back. It has also been reported to be an effective non-pharmacological intervention for patients with low back pain. Relatively short exposure to whole body vibration has been also shown to increase the serum levels of testosterone and growth hormone. The combined effects on the neuromuscular system and endocrine system seem to suggest its effectiveness as a therapeutic approach for sarcopenia and possibly osteoporosis."

- Lackawanna, NY, USA

The GMC Sierra has a terrible vibration from 70 - 80 mph. It has been in the shop 7 times over the last year, 9 new tires, and the vibration still continues. I have attempted to resolve the issue with GM but there has been no resolution. The truck feels unstable and like something is going to break on the highway which is a safety concern. This vehicle has issues and it needs addressed.

- Topeka, KS, USA