AI Damage2021 Audi S4: common problems
Owners of the 2021 Audi S4 filed 2 complaints with NHTSA, most often about electrical system. The maker issued 959 service bulletins for this year. Details by component below, with sources.
Key figures
- Owner complaints
- 2
- Technical service bulletins (TSB)
- 959
What fails most often
- Electrical system: 1 complaints (50% of all); manufacturer bulletins for this component: 314.
Engines and transmissions
US-market versions per EPA. On the right: how many NHTSA complaints name this engine or transmission type.
- 3 L · petrol · turbo · 6 cyl
- automatic, 8-speed
Drive: AWD
Symptoms owners describe
How many of the 2 NHTSA complaints mention each symptom (automatic count from complaint text; one complaint can mention several).
Components owners complain about
| Component | Owner complaints | involving a crash | Technical service bulletins (TSB) |
|---|---|---|---|
| Electrical system | 1 | 0 | 314 |
| Equipment | 0 | 0 | 226 |
| Structure | 0 | 0 | 93 |
| Steering | 0 | 0 | 45 |
| Visibility | 0 | 0 | 44 |
| Engine and cooling | 0 | 0 | 42 |
| Service brakes | 0 | 0 | 42 |
| Engine | 0 | 0 | 41 |
| Suspension | 0 | 0 | 41 |
| Powertrain | 0 | 0 | 35 |
| Wheels | 0 | 0 | 18 |
| Exterior lighting | 0 | 0 | 15 |
| Fuel/propulsion system | 0 | 0 | 12 |
| Backover prevention | 0 | 0 | 10 |
What owners report
Short excerpts of NHTSA complaints in the original wording. These are owner statements not verified by NHTSA; personal data removed.
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.
When owners complained
NHTSA complaints by filing year. The peak shows at what age the problems show up most.
Comparison
By complaint count this model year ranks 1,862 of 2,102 model years in the NHTSA data (among the 11% least complained about).
On average one model year of the S4 has 3 complaints (11 years in the data). This year has 2, below average.
What to check before buying
- Electrical system. Scan all modules, test the battery and alternator, inspect connectors near the impact zone.
- Structure. Rails, pillars, panel gaps, signs of pulling or welding.
- Steering. Steering play, power assist, rack and tie rods after a wheel impact.
- Visibility. Wipers, mirrors, defrosters, cracked glass.
Manufacturer service bulletins
Bulletin titles as filed with NHTSA.
- This bulletin states that technicians are required to report to the manufacturer when a vehicle has…
This bulletin states that technicians are required to report to the manufacturer when a vehicle has flooded, and specify the height to which the vehicle has been flooded.
- This bulletin provides information when there is an abnormal knocking noise from the engine compartment;…
- This bulletin provides information regarding fault finding and repair information for electric tailgate
- This bulletin provides information about billing for a broken sunroof glass panel
- This bulletin provides information about vibrations and rotational steering vibrations
- This bulletin provides information when there are stails/marks on the sill panel trim
- This TSB describes a corrosion issue due to outside influence and the prohibition of warranty in these cases
- This bulletin provides information when the rear parking sensor sometimes does not work, rear parking…
This bulletin provides information when the rear parking sensor sometimes does not work, rear parking sensor loose, rear parking sensor fault message.
- This bulletin provides informaiton when DTC B200FF0 is stored
- This bulletin provides information for reporting safety related information to the manufacturer
- This bulletin provides infomraiton abou the Audi frequency analysis application, which is available in the…
This bulletin provides infomraiton abou the Audi frequency analysis application, which is available in the App Store for Android and Apple phones.
- This bulletin provides information when the license plate mounting bracket threded inserts are stripped
NHTSA lists 959 bulletins for this year; the 12 newest are shown here.
Other years of this model
Questions and answers
What are the most common problems with the 2021 Audi S4?
Owner complaints to NHTSA most often mention: electrical system. Total complaints: 2. The most frequent symptoms in complaint texts: hesitation when accelerating (50%), warning lights, check engine (50%).
How many service bulletins (TSB) were issued for the 2021 Audi S4?
NHTSA lists 959 manufacturer service bulletins for this year. A bulletin tells dealers how to diagnose or fix a known issue; it is not a recall.
Should I buy a 2021 Audi S4 from a US auction?
Owner complaints describe defects, not crash damage. Before bidding, check the components listed above and review the lot photos: VinWind builds a report of visible and hidden damage by VIN.
Other 2021 models
Read also
Sources: public NHTSA data (USA): service bulletins and owner complaints; YouTube: links to videos credited to their authors. Complaints are owner statements not verified by NHTSA, and describe defects rather than crash damage. Data updated 2026-11-04.