Accelerates on its own

There are only about 400 complaints like this across the vehicles covered here, too few on any one vehicle year to earn a sheet of their own. What they lack in numbers they make up in outcomes: 210 mention a crash and 114 an injury. The median mileage owners give is about 14,000, so these are mostly newer cars. About half mention parking and about half mention the brakes.

The recall files hold very few of these. Ford's 22V-333 updated powertrain control software on some 2021 Mustang Mach-E models with all-wheel drive, after the software could fail to catch an error that might cause unintended acceleration, unintended slowing or a loss of drive power. (The fix could be done at a dealer or over the air.)

If it happens, get the car stopped and parked as safely as you can. Then leave it parked until it has been looked at, and photograph the dash if any warnings are showing.

At the dealer, ask for any stored codes to be read and printed, and ask that everything they check be written on the repair order, including "no fault found" if that's the result. About one report in six in this group includes words like "nothing" or "normal," and a written record is what you'll have if that's where it ends. Be exact about the moment it happened: gear, speed, where your feet were, whether a driver assist feature or cruise control was on.

File a report with NHTSA, even if the dealer can't find anything. NHTSA says it reviews every complaint, and when it gets similar reports from a number of people about the same product, that can point to a safety defect that warrants an investigation, which can lead to a recall. Check the VIN on NHTSA's recall lookup, and if the car is under warranty, the FTC says a defect reported during the warranty period must be fixed even if the warranty ends before the repair.