There are 4 owner-reported electrical system complaints for the 2020 Toyota Siennain NHTSA's database. These are unverified consumer reports and may not reflect confirmed defects.
The contact owns a 2020 Toyota Sienna. The contact stated that while his wife was driving at an undisclosed speed, the pre collision, lane assist, and air bag warning lights illuminated on the instrument panel. The vehicle was taken to a dealer and a fuse in the ECU (Electronic Control Unit) was replaced; however, the contact stated that approximately 10 days later, the failure recurred. The vehicle was taken back to the dealer where the vehicle remained for almost two weeks. The contact was informed that the wiring harness needed to be replaced; however, the wiring harness was on backorder. The manufacturer was notified of the failure, but no additional assistance was provided. The contact was provided a case number. The vehicle was not repaired. The failure mileage was approximately 60,000.
Spontaneous and random: Blinkers come on, radio volume goes up or down when turning the other way, CarPlay USB shuts off and on, hiccups when accelerating (when ECO kicks on/in)…everything points to an electrical/computer issue. Purchased used from a dealership and noticed these issues after the 3-day return window.
Speakers make an ear piercing loud noise that lasts about a second. If this sound were to occur during travel, could cause distraction leading to harm, or with young kids in the car, possibly damage their ears. This problem has been random and not experienced by a dealership. No warning messages or symptoms to the problem. Problem first appeared 6 months ago.
DEAR TO WHO CONCERN THIS CASE, ON AUGUST 26, 2019, I PURCHASED A BRAND NEW CAR, SIENNA, TOYOTA 2020 FROM PRINCIPLE TOYOTA ON 7370 WINCHESTER RD, MEMPHIS, TENNESSEE 38125. I DISCOVERED THAT THERE ARE MAJOR ISSUES WITH THE CAR. I WAS GUARANTEED BY THE DEALER THAT THE CAR IS IN PERFECT WORKING CONDITION BEFORE PURCHASE. HOWEVER, AFTER DRIVING THE NEW CAR FOR FEW DAYS, THE KEY REMOTE STOPPED WORKING AND I REVISITED THE DEALERSHIP TO GET IT FIXED. I TALKED TO JIMMY ROCKER, ONE OF THE SALE ASSOCIATES, AND HE TRANSFERRED ME TO THE TOYOTA SERVICE CENTER. AFTER FEW MORE DAYS OF DRIVING THE CAR, MORE PROBLEMS EMERGED. THE CAR WARNING MONITOR INDICATED 'AWD SYSTEM MALFUNCTION 2WD MODE ENGAGED, CONTACT YOUR DEALER' AS WELL AS 'BRAKE OVERRIDE MALFUNCTION, VISIT YOUR DEALER'. NOT ONLY THE WARNINGS, THE CAR SUDDENLY STOPPED ON THE HIGHWAY. LUCKILY THERE WERE NO CARS BEHIND ME, OTHERWISE I WOULD HAVE BEEN INJURED. THE SECOND TIME I REVISITED THE DEALERSHIP, I ENCOUNTERED CHRIS THOMPSON, THE NEW CAR DIRECTOR AT PRINCIPLE TOYOTA. I SUGGESTED HIM TO INSPECT MY CAR AND FINDING A SOLUTION FOR IT. I HAVE TRIED TO EXPLAIN TO HIM HOW IT WAS DANGEROUS FOR ME AND MY FAMILY. I HAVE TWO KIDS WHO ARE DRIVING WITH ME AND IF THE SITUATION HAPPENED AGAIN, WE WOULD HAVE BEEN FATALLY INJURED. CHRIS DID NOT LISTEN TO MY STORY BUT INSTEAD TOLD ME THAT THE CAR DOES NOT BELONG TO HIM AND HE JUST WALKED AWAY IN FRONT OF OUR CONVERSATION. I WAS VERY DISAPPOINTED BECAUSE OF HIS INDIFFERENCE TOWARDS MY SITUATION AND THE TYPE OF CUSTOMER SERVICE I RECEIVED WAS NOT EXPECTED FROM A WELL-KNOWN COMPANY LIKE YOURS. TO ENSURE THE SAFETY OF KIDS AND MY FAMILY, I DEMAND A REPLACEMENT OF THE CAR AS WELL AS ANY COMPENSATION ASSOCIATED MY SPENT TIME AT THE DEALERSHIP. I HOPE THERE WILL BE A REASONABLE SOLUTION FOR MY CASE. BEST REGARDS, [XXX] REDACTED TO PROTECT PERSONALLY IDENTIFIABLE INFORMATION PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6). *CC *TR
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.
Data synced from NHTSA on Apr 26, 2026