There are 1 stored owner reports matching the driver assist & adas leading-label group for the 2021 Audi A4 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 1 of 1 matching reports.
Open the full vehicle complaint log (all categories)On several occasions while vehicle was stationary at a stoplight or moving very slowly the emergency braking system deployed, with seat belt tensioner activated and brakes applied with characteristic thunk sound. I could discern no threat at the time, but other cars were nearby. Recently, though, while in the middle of a left turn across three lanes of oncoming traffic (the nearest car was a block away) the car suddenly braked to a full stop. Nothing was behind or alongside me. It took about two seconds for the brake to release and I could accelerate forward. If there had been more traffic there could have been a front or rear collision. I took the car to the dealer who kept it all day and did nothing to it. Review of internet sites indicates that this is a not uncommon problem and that Audi has no solution. My son has 2 Audis, (SQ5s), and says this has happened to him in both of his vehicles.
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: Aug 31, 2026. This is the stored import date, not confirmation that every source was successfully refreshed.