Problems · NHTSA complaints
2021 Audi S4 problems
Owners filed 2 complaints about the 2021 Audi S4 with NHTSA between Jan 2023 and Sep 2025. The most-cited component is electrical system (1).
Complaints
2
Filed with NHTSA
Crashes
0
Reported by owners
Fires
0
Reported by owners
Injuries
0
People reported injured
Deaths
0
Reported to NHTSA
Complaints by component
One complaint can cite several components
- Electrical system1
- Other / unknown1
Complaints are unverified owner reports to NHTSA and are not normalized for sales volume. One complaint can cite several components.
Data from NHTSA Complaints API · synced Oct 30, 2026NHTSA vehicle page
When complaints were filed
Does it get worse with age? Complaints per calendar year filed
1
0
1
View as table
| Model year | Complaints filed per calendar year |
|---|---|
| 2023 | 1 |
| 2024 | 0 |
| 2025 | 1 |
Mileage at failure isn’t a structured field in NHTSA complaint data, so we don’t chart it. Some owners mention it in their reports below.
Top problems in owners’ words
Verbatim from NHTSA complaints, newest first
Electrical system
1 report
“The contact owns a 2021 Audi S4. The contact stated that while driving at an undisclosed speed, the vehicle experienced a loss of automotive power. The check engine warning light was illuminated. The message "Drive System Malfunction - Please Contact Service" was displayed. In addition, the vehicle hesitated to restart and shift into gear as intended. The contact stated that the failure had progressed over time. The vehicle was taken to a local dealer, where it was diagnosed with needing a pending software service update; however, the repairs would not be available until the end of 2025. The manufacturer was made aware of the failure. The failure mileage was approximately 31,000.”
Data from NHTSA Complaints API (owner reports, unverified) · synced Oct 30, 2026
Complaints are unverified owner reports to NHTSA and are not normalized for sales volume. One complaint can cite several components.