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What 145 owners told NHTSA about the 2021 GMC Acadia Denali

These are the actual owner complaints behind this car’s reliability verdict, filed with the federal government, unedited. They’re unverified reports, not confirmed defects: read them as leads for your pre-purchase inspection, not a diagnosis.

All (145)Crash / fire / injury (7)Electrical system (37)Engine (29)Fuel system (27)Brakes (17)Transmission & drivetrain (17)Steering (15)Airbags (8)Backup camera & sensors (7)Speed control (7)Driver assistance (6)

27 of 145 complaints match · Fuel system · clear filters · page 2 of 2

Nov 15, 2022Electrical systemFuel system

WAS DRIVING AND VEHICLE ENGINE DEAD STOPPED WITH OUT WARNING. COULD NOT GET STARTED AND HAD TO CALL A WRECKER TO TOW TO GMC DEALERSHIP. WERE TOLD IT WASN'T THE FIRST TIME THAT THEY HAD SEEN THIS. THEY HAD A PART IN STOCK TO REPAIR IT. IT WAS DIAGNOSED AS THE “DRIVERS FUEL PUMP MODULE” .WAS SURPRISED THAT THERE WAS NOT A RECALL AS THIS COULD HAVE BEEN A DEADLY INCIDENT DURING RUSH HOUR ON THE ROADS IN MY AREA. WHILE RESEARCHING FOUND A RECALL ON FULL SIZE GMC 2021 SUVS FROM LAST YEAR (NHTSA CAMPAIGN NUMBER 21V739000) ! WHY IS THIS NOT BEING DEALT WITH ON THE 2021 ACADIAS? MY DAUGHTER HAS ONE SHE BOUGHT THE SAME DAY AND NOW I AM IN FEAR IT WILL DO THE SAME THING !!! NO INSURANCE ISSUES OR POLICE ISSUES. AFTER ENGINE DIED SEVERAL SYMBOLS INCLUDING ENGINE ICON CAME ON WHEN TRYING TO RESTART. ALSO RECEIVED AN EMAIL “DIAGNOSTIC ALERT” FROM ON STAR IMMEDIATELY : AN ISSUE WITH THE ENGINE AND TRANSMISSION SYSTEM IN YOUR 2021 GMC ACADIA HAS BEEN DETECTED. PLEASE SERVICE YOUR VEHICLE WITHIN 7 DAYS….

NHTSA ODI 11493628

Feb 2, 2022Speed controlFuel system

Brand new vehicle purchased from dealer, at 8900 miles transmission slipped. Dealer has for 2 hours and couldn’t find problem, but replaced transmission fluid it was dark. At 9000 it happened again, they have vehicle and said the new transmission fluid is dark and muddy. Only 100 miles, so they determined they need to take apart transmission and see what happened. It’s a 52k car, it should not be repairs, it should be replaced under warranty. Video of 8900 from dealership https://video.37483.net/timeline/2CJTHEW6

NHTSA ODI 11450038

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Working with the data? Download all 145 complaints as CSV · fetched from NHTSA July 25, 2026

How to use these: a complaint is one owner’s report, filed voluntarily and published unverified. Patterns matter more than any single story. If several owners describe the same failure at similar mileage, put that system at the top of your pre-purchase inspection list. Back to the full 2021 GMC Acadia Denali verdict →