Cadillac CT6 Reliability by YearBest & worst years, problems & recalls — NHTSA data

Vehicle has sudden violent forward Jerking motion at stops, delayed performance when accelerating ,hard shifting when changing gears, clunking noise when shifting into low gear

WHEN I AM TURNING UNDER 25 MPH, I ACCELERATE AND THERE IS A DELAY AND A DRAG BEFORE THE VEHICLE STARTS TO ACCELERATE. IF I DO NOT ALLOW ROOM, I COULD GET HIT BECAUSE THERE IS A DELAY. VERY DANGEROUS. ALMOST FEELS LIKE A VACUUM ISSUE.

CAR WILL NOT RESPOND FOR AT LEAST 2 SECONDS DURING A SLOW, ROLLING STOP, WHEN TRYING TO ACCELERATE AGAIN. UNABLE TO PERFORM EVASIVE MANUEVER, IF NEEDED, SECONDARY TO THE DELAY TO ACCELERATOR INPUT. HARSH 2-1 DOWNSHIFTS ALSO AT SLOW SPEEDS AND CAN EVEN FEEL AS THOUGH YOU WERE STRUCK FROM BEHIND. HIGHWAY DRIVING IS EXCELLENT; CITY DRIVING CHALLENGING WITH THE TRANSMISSION. THE DRIVER HAS TO LEARN HOW TO DRIVE THIS VEHICLE. FIND IT VERY UNUSUAL AFTER OWNING 5 OTHER CADILLACS AND NEVER HAD THIS PROBLEM. I BOUGHT THIS CAR AS A PRE-OWNED CERTIFIED VEHICLE FROM CADILLAC DEALER. THE CAR HAD 650 MILES ON IT AND I TRULY BEATIFUL/SHOWROOM CONDITION. I HAD THE TRANSMISSION RE-FLASHED, WHICH PROVIDED PERHAPS A 1-2 DAYS RELIEF. I WILL CONTINNUE TO PERSUE WITH DEALER, BUT WANTED YOU GUYS TO BE AWARE. CADILLAC SHOULD FIX THE PROBLEM; NEW/DIFFERENT TYPE OF TRANSMISSION OR RE-WORK THE 8L45/8L90'S WITH DIFFERNET VLAVES/SOFTWARE OR BUY IT BACK FROM ME.

The contact owns a 2019 Cadillac CT6. The contact stated that while driving at an undisclosed speed, the transmission unexpectedly shifted hard, and the service warning light was illuminated. The contact stated that while accelerating and decelerating, the vehicle shuddered and hesitated. There was smoke coming from the vehicle. The vehicle was taken to the dealer on several occasions. The dealer diagnosed the vehicle with transmission failure. The contact was informed that the transmission needed to be replaced. The contact stated that the failure was associated with a previous transmission software update. The failure mileage was approximately 47,000.

On July 22, 2025, at 20,245 miles, I brought my 2019 Cadillac CT6-V to an authorized dealer while still under factory warranty, reporting hard shifting during both acceleration and deceleration — the exact symptom described in GM Special Coverage Bulletin N242480631, which addresses a defective transmission control valve subject to premature wear (P0747 diagnostic condition). The dealer was unable to diagnose or repair the issue at that visit and returned the vehicle to me without resolving the defect. The same condition recurred. I brought the vehicle back to the dealer (Crestview Cadillac, Rochester Hills, MI) on May 26, 2026. The vehicle remained at the dealership for over three weeks before any loaner vehicle was offered. Replacement parts were reported as received on July 3, 2026, and again on July 17, 2026, and as of this filing the vehicle has still not been returned to me — over two months out of service. The repair estimate is approximately $12,000, covering the transmission control valve, a power transfer case, and a high-pressure oil pump. GM Special Coverage Bulletin N242480631 states that the control valve body replacement is covered at no charge for vehicles that return with a P0747 condition after the TCM software update, for 15 years or 150,000 miles from the in-service date, regardless of ownership. My vehicle meets these conditions. Despite this, GM's case team has offered only a $4,500 "goodwill" credit plus reward points toward the total repair, characterizing this as a discretionary gesture outside of warranty, and has stated this is their final position. I am filing this complaint because: (1) the original recall/coverage remedy did not resolve the underlying defect when I first brought the vehicle in under warranty, resulting in continued use of a vehicle with an unrepaired safety-related transmission defect until the condition worsened; (2) GM's dealer network has taken an extended and, in my view, excessive amount of time to complete.

The contact owns a 2019 Cadillac CT6. The contact stated that while driving approximately 75 MPH, the wheels locked up and the vehicle started swaying from side to side, and the vehicle decelerated. The contact was able to coast to the side of the road and had the vehicle towed to an independent mechanic. The vehicle was diagnosed with rear differential failure, and DTC: P0747 (Transmission Solenoid Stuck Open); was retrieved. The differential was replaced. The contact then received notification of NHTSA Campaign Number: 25V148000 (Power Train); and the vehicle was taken to the dealer and repaired under the recall. The contact stated that after the recall repair, the transmission experienced hard shifting, with the check engine warning light illuminated. The contact stated that the check engine warning light was illuminated before the recall was issued. The vehicle was returned to the dealer, but was not diagnosed or repaired. The manufacturer was not made aware of the failure. The failure mileage was approximately 77,000. The VIN was not available.

The contact owns a 2019 Cadillac CT6. The contact received notification of NHTSA Campaign Number: 25V148000 (Power Train); however, the part to do the recall repair was not yet available. The contact stated while driving at various speeds, the vehicle shuddered, and the transmission was shifting hard. There was no warning light illuminated. The vehicle was taken to the dealer, where it was diagnosed with a fractured transmission control valve. The dealer informed the contact that the failure was related to the recall, but the part to do the recall repair was not yet available. The vehicle was not repaired. The contact stated that the manufacturer had exceeded a reasonable amount of time for the recall repair. The manufacturer was not made aware of the failure. The failure mileage was approximately 65,000. Parts distribution disconnect.

The contact owns a 2019 Cadillac CT6. The contact received notification of NHTSA Campaign Number: 25V148000 (Power Train); however, the part to do the recall repair was not yet available. The contact stated that the manufacturer had exceeded a reasonable amount of time for the recall repair. The dealer was made aware of the issue and confirmed that parts were not yet available. The manufacturer was made aware of the issue and confirmed that parts were not yet available. The contact had not experienced a failure. Parts distribution disconnect.

The contact owns a 2019 Cadillac CT6. The contact received notification of NHTSA Campaign Number: 25V148000 (Power Train); however, the part to do the recall repair was unavailable. The local dealer was contacted, and it was confirmed that the part was not yet available. The contact stated that the manufacturer had exceeded a reasonable amount of time for the recall repair. The manufacturer was made aware of the issue. While driving approximately 70 MPH, the wheels locked up, causing the vehicle to lose automotive power and decelerate. The vehicle was driven to the local dealer who diagnosed that the transmission had failed and needed to be replaced. The vehicle was not repaired. The failure mileage was 84,000. VIN tool confirms parts not available.

The contact owns a 2019 Cadillac CT6. The contact received notification of NHTSA Campaign Numbers: 25V148000 (POWER TRAIN); however, the part to do the recall repair was not yet available. The contact stated that upon parking and exiting the vehicle, the vehicle rolled backwards approximately 1 to 2 feet. The driver's door was ajar with the driver’s foot near the vehicle, and the contact was able to depress the brake pedal and stop the vehicle. The contact pressed the Push to Start button, and after several attempts, moved the column shifter back and forth until the vehicle shifted to drive(D). There was no warning light illuminated. The contact stated that on a separate occasion, while in line at the drive-thru, the column shifter was stuck on neutral(N). After several attempts, the contact was able to move the gear shifter to drive(D). Most recently, the contact stated that upon parking and exiting the vehicle, the vehicle started to roll back 1 to 2 feet. Additionally, the contact engaged the parking brake. No warning lights were illuminated. The vehicle was taken to several dealers, including Schepel Cadillac (2929 W Lincoln Highway, Merrillville, IN 46410). The vehicle was not diagnosed or repaired. The contact stated that the manufacturer had exceeded a reasonable amount of time for the recall repair. The contact notified GM's Chief Executive of the failure through email. The failure mileage was approximately 50,000. VIN tool confirms parts not available.

The contact owns a 2019 Cadillac CT6. The contact received notification of NHTSA Campaign Number: 25V148000 (Power Train); however, the part to do the recall repair was not yet available. The local dealer was contacted and confirmed that parts were not yet available. The contact stated that the manufacturer had exceeded a reasonable amount of time for the recall repair. The manufacturer was made aware of the issue. The contact had not experienced a failure. VIN tool confirms parts not available.

On several separate occasions, my Cadillac CT 6 which has been under recall for months by General Motors does not have an adequate repair for the repair shops authorized by the manufacturer, namely GM franchised Cadillac dealer repair shops and hence I am unable to have my vehicle repaired because the franchised GM dealers inform me that due to the recall and General Motor’s refusal or inability to provide specific reason for the transmission failure and the automobile not being able to shift into park when it is on an incline has rolled backwards when my door was open. I was attempting to get out of the car when it began rolling backward I was able to step on the brake: I would’ve been severely crippled or killed. Further to the preceding I have contacted CEO Mary Barra pertaining to the preceding and an executive inquiry person named “Thomas” informed me he will call me back with a resolution and has not done so. I do not have any other vehicle. I am a [XXX]. I have [XXX] and I cannot utilize my car safely and General Motors: Refuses to give me a replacement car, refuses to provide the franchisee with a written cause for the failures and solution for their mechanics to fix the vehicle, and therefore I respectfully request that the manufacturer be mandated to buy this vehicle back for its full purchase price: that they sold it to me defective knowing that there was a defect in this transmission and that they previously have covered up engine failure when the CEO was Mary Barra, the CEO again is Mary Barra, and she authorized General Motors to pay to the federal government $900 million because General motors “covered up” the engine defect in 2015 and approximately 3 to 4 years later in 2018–2019 CEO Mary Barra & GMC commit recidivism and in 2025 place me in harms way. I emailed Mary Barra directly as well as called her office and she refuses to inform me what the cause of this failure of the transmission and powertrain is. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)