There are 3 stored owner reports matching the powertrain & transmission leading-label group for the 2018 Cadillac CT6 in our NHTSA-sourced dataset. These are unverified consumer reports and may not reflect confirmed defects.
This group counts stored reports whose component label starts with one of this site's matching prefixes, ignoring case. Each matching report counts once within the group. Components mentioned later in the label or only in the narrative are not searched. How component counts work
Loaded 3 of 3 matching reports.
Open the full vehicle complaint log (all categories)Front differential case ripped in half and separated from the ring gear. The broken chunk of differential case and pinion was still attached to the driveshaft while coming to an abrupt stop. Damage done within driveshaft tunnel. No warning, no vibration, no cause for concern, just catastrophic failure. Differential and propeller shaft were replaced by an independent mechanic. Cadillac has not been notified as of today, receipt for repair available upon request.
MY CADILLAC CT6 (2018) QUIT WORKING WHILE ON THE EXPRESSWAY. I WAS IN THE MIDDLE OF NO WHERE, IN GEORGIA. THIS MADE FOR A VERY DANGEROUS SITUATION AS THE CAR SUDDENLY LOST ALL POWER GOING TO THE WHEELS WHILE DRIVING AT APPROX. 75 MPH. I WAS BARELY ABLE TO GET AROUND TRAFFIC TO BE ABLE TO PULL OVER AS THERE WAS 0 POWER. WHEN THE TOW TRUCK FROM CADILLAC ARRIVED WE WERE TOLD WE WERE NOT ALLOWED TO RIDE IN THE TRUCK BECAUSE OF COVID. WE WERE MADE SIT IN THE RAIN IN 40 DEGREE WEATHER WHILE I SPOKE WITH MY HOME CADILLAC DEALER AS WELL AS THE NEAREST TO WHERE I WAS. BOTH DEALERS WERE EXTREMELY UNHELPFUL, MY CAR IS STILL UNDER FACTORY WARRANTY AND WAS JUST IN FOR TRANSMISSION WORK ABOUT A WEEK PRIOR (I'VE TAKEN THE CAR IN THREE TIMES FOR TRANSMISSION ISSUES AND IT STILL HAS SOMETHING WRONG WITH IT. I WAS TOLD BY BOTH CADILLAC DEALERS THAT THEY WOULD NOT HELP BECAUSE THEY NEEDED TO 'DIAGNOSE' THE CAR AND COULDN'T UNTIL FIVE DAYS LATER. I WAS OFFERED AN UBER RIDE IN A CITY THAT HAD 0 ZERO UBER, TAXI OR LIFT SERVICES. I WAS HUNG UP ON BY THESE PEOPLE, THEY WERE RUDE AND THIS WAS ON CHRISTMAS EVE. I HAD TO WALK TO A CAR RENTAL COMPANY AND PAY OVER $400 DOLLARS SO I COULD SPEND CHRISTMAS WITH MY FAMILY.
LOSS OF ALL VEHICLE POWER WHILE TRAVELING ON THE FREEWAY AT HIGHWAY SPEEDS. VEHICLE CHECK ENGINE, POWER LIMITED, AND ELECTRIC MOTOR OVERHEAT WARNING LIGHTS COME ON. THE COMBUSTION ENGINE WILL NOT START, AND BATTERY POWER AVAILABILITY GOES TO ZERO. THIS IS VERY DANGEROUS TO PUBLIC HEALTH AND SAFETY DUE TO INSTANTANEOUS LOSS OF COMBUSTION ENGINE AND ELECTRIC BATTERY POWER WHILE IN FAST-MOVING HIGHWAY TRAFFIC. THERE ARE SEVERAL INSTANCES OF THIS SAME PROBLEM OCCURRING IN MANY CADILLAC OWNERS FORUMS, SO GENERAL MOTORS KNOWS THERE IS A PROBLEM WITH THEIR CT6 PHEV TRANSMISSIONS. THE FIX SEEMS TO BE REPLACING THE TRANSMISSION DUE TO A BAD CLUTCH PACK, BUT PEOPLE COULD GET HURT IF THIS ISSUE IS ALLOWED TO CONTINUE WITHOUT A PERMANENT SOLUTION.
Complaints are unverified consumer reports submitted to NHTSA. A high complaint count may reflect vehicle popularity, not defect severity. Data sourced from NHTSA public records.
NHTSA source checks for this vehicle year
Checks are recorded separately for each dataset, not for the whole page. Dates use UTC. A missing check date does not mean no records exist.
Vehicle import recorded: Apr 28, 2026. This is the stored import date, not confirmation that every source was successfully refreshed.