I was driving the vehicle heading to the interstate, and my speed was about 15 MPH, as I merge onto the highway and accelerated I felt the transmission shudder, and lag with a humming noise. It felt like the transmission mission was slipping and shaking with no acceleration power. I had to keep hitting the gas pedal to try and make the transmission engage. Very Dangerous! The transmission would also throw you back and jerk when accelerating violently. The transmission lunges forward and jerks into gears when starting from 0 mph.

- Harrisburg, NC, USA

While driving the vehicle with auto stop engaged, the auto stop was malfunctioning. When I get to a red light or stop sign vehicle would engage auto stop, once I let my feet off the gas pedal and accelerate, the vehicle would jerk out of gear then slip /drag then engage with a loud hit as if someone rear-ended me. The problem was duplicated and confirmed by the dealership. There has been no outside inspection other than the dealership. No warning lights messages prior to failure. In addition, the Auto-stop working with a week of this complaint shortly therafter.

- Harrisburg, NC, USA

The contact owns a 2017 Cadillac CT6. The contact stated that while driving at various speeds, the vehicle would hesitate upon depression of the accelerator pedal without warning. The contact had taken the vehicle to a dealer where they initially changed the transmission fluid and reprogrammed the transmission module; however, the failure persisted. The contact returned the vehicle to the dealer and she was informed that the torque converter was defective; but that the cost to replace the transmission was expensive. She was advised to bring the vehicle back to dealer each time the hesitation occurred to have the transmission fluid replaced. The manufacturer had yet to be notified of the failure. The vehicle had yet to be repaired. The failure mileage was approximately 14,000.

- Houston, TX, USA

My 2017 Cadillac CT6 3.0 tt premium luxury has had this issue since I purchased it. Dealership state that this is normal and I should live with it. If I knew this before I purchase this $98,000 vehicle I would have gone Mercedes-Benz. The issues with the 8-speed 8L90 GM transmission are two-fold. First, the transmission shudders frequently. Secondly, the shifts are very harsh between first to second, and then second down to first, especially when accelerating and the transmission is upshifting or decelerating and the transmission is downshifting. These conditions are most commonly observed under light and medium throttle applications, and as often during full throttle applications. I have had the tsb 18-na-335 done and issues still remaiins.

- Wellton, AZ, USA

When auto stop is engage taking your foot off the brake pedal from a complete stop when the engine starts back up it has a harsh jerk sometimes, it feels as though someone has hit you from the rear. This been going on for three years the car has been in service twice for this problem the service technician cannot duplicate it.

- Novi, MI, USA

On more than three occasions, this vehicle has lost substantial or all propulsion due to engineering design defects with the gas/hybrid electric transmission system. All but one of these situations occurred on a high speed freeway causing potentially life threatening conditions when the vehicle substantially slowed or stopped. This is a known issue as is evidenced by other owners of this vehicle reporting the same issue and the manufacturer failing to have a viable permanent remedy. As of today's date, 3/4/2020, the vehicle has been in the shop for the past 62 of 92 days and is still awaiting repairs. This first occurred when the vehicle had less than 10,000 miles.

- San Marcos, TX, USA

The contact owns a 2017 Cadillac CT6. When the vehicle was started, it lurched forward without warning. The failure occurred intermittently. The vehicle was taken to gold coast Cadillac (732-709-2168, located at 2123 state route 35, oakhurst, NJ 07755), but the cause of the failure could not be determined. The manufacturer was made aware of the failure and referred the contact back to the same dealer. The dealer provided a technical service bulletin (document id number: 4605342 - 16-na-361: Information on transmission harsh 1-2 shift upon first startup/shift of the day under light throttle (Jul. 21, 2017)). The contact was informed that there was no remedy for the failure. The vehicle was not repaired. The failure mileage was approximately 1,700. Consumer stated vehicle lurched forward again on 12/18/19. Car was taken in for service on 10/2019.

- Monroe Township, NJ, USA

I purchased the used 2017 Cadillac CT6 in March 2019 with 24,192 miles. It was a certified pre -owned car by the dealer. Additionally I purchased a cpo protection plus protection plan with the car. I am experiencing problems with the transmission. During acceleration and decelerating the car feels a hesitation followed by a significant shake, shudder, jerk, clunk or hard shift. The auto start stop feature is not working correctly. When you come to a light the engine will turn off and when it restarts it will jerk into gear so violent that it feels as though the vehicle has been hit from behind. Additionally at 35, 45, and 55 miles pre hour the vehicle makes a whining noise either from the transmission or differential. I have had the car in for repairs four times at the dealership with no success on correcting the problems.

- Temperance, MI, USA

Hard shifts in low speeds, intense vibration, shudder throughout driving speed. Cadillac dealer said it is torgue converter issue, car transmission needs to be fluid exchanged for $800.

- Stone Mountain, GA, USA

Transmission has a signification clunk/hesitation/delay shifting up from 1st-2nd gear and down from 2nd-1st gear. In the upshift, the car violently lunges forward once the acceleration rev from the push of the pedal catches up with the gear shifting, no matter how delicately you might push the pedal. Feels like the vehicle has been hit from behind once it catches. In the downshift, upon braking to come to a stop, the car pulsates and lunges forward as well which has caused me to nearly hit the car in front of me on several occasions and if no car is in front of me it has caused me to creep out into the intersection a bit. This has happened regularly since my acquisition of the vehicle in early April 2018 and the dealer has reviewed and advised that it shifts just fine.

- Raymore, MO, USA

I have had issues with my vehicle that involves hard shifting at times and also, the vehicle sometimes will lurch quite abruptly. It actually feels as if the vehicle was rear ended. I have taken the vehicle to the dealership on 4 occasions and they were only able to "replicate" the problem one time. This hard shift/lurching occurs usually when at a stand still and, once you remove your foot from the brake, vehicle may shift hard. It doesn't matte where I am; whether on streets or on the freeway. If vehicle is stopped, then this happens on occasion. It doesn't matter if I am using the "autohold" feature or not but it doesn't seem to occur as often if I am using the "sport" mode when driving. The last time this event occurred, the dealership kept the car for 3 days and claimed that they could not replicate the problem, but, I drove away and the issue occurred with me less than 2 miles from the dealership. I have 2 grandsons that I "taxi" around and they have both felt this problem. As a matter of fact, anyone who rides in my car is aware of this problem but, for some reason, Cadillac is stating that there is nothing wrong with the vehicle. The first time this occurred was on 9/13/17; again on 10/5/17. (term used was ccnd - customer concern not duplicated). Now, on 11/03/17 they duplicated

- West Covina, CA, USA

Vehicle's transmission lurches and slips out of gear in coast conditions; during turns and in intersections.

- Geneva, NY, USA