2021 Audi A4 Problems: 2 Known Issues
2021 model year · NHTSA recalls, manufacturer TSBs, and owner forum reports · Updated October 2026
According to Au7o's research across NHTSA recalls, manufacturer TSBs, and owner forum reports, the 2021 Audi A4 has 2 documented known issues, with 1 rated critical. The most serious is 2021-2022 A4 Rearview-Camera Software Recalls 91DZ / 91CR - VIN Check Required. DIY maintenance guides at au7o.io.
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All 2 Known Issues
NHTSA Recalls8 recalls
SEATS
Volkswagen Group of America, Inc. (Audi) is recalling certain 2017-2020 A4 Allroad, A4 Sedan, 2018-2019 RS5 Coupe, 2019 RS5 Sportback, 2018-2020 A5 Cabriolet, A5 Coupe, A5 Sportback, S4 Sedan, S5 Cabriolet, S5 Coupe, and Audi S5 Sportback vehicles. The cable connecting the seat heater to the Passenger Occupant Detection System (PODS) may have a contact fault, causing the software to misdiagnose a malfunction and disable the passenger air bag.
TIRES
Volkswagen Group of America, Inc. (Audi) is recalling certain 2019-2021 Audi A5 Sportback, RS5 Coupe, RS5 Sportback, S5 Sportback, 2020-2021 A4 Allroad, A4 Sedan, A5 Cabriolet, A5 Coupe, A6 Allroad, A6 Sedan, A7, A8, Q5, S4 Sedan, S5 Coupe, S5 Cabriolet, S6 Sedan, S7, S8, SQ5, 2021 Q5 Sportback, Q7, Q8, RS6 Avant, RS7, RSQ8, SQ5 Sportback, SQ7, and SQ8 vehicles. The rear axle alignment may not have been inspected after the repairs for Recall 21V-295 (42L1) were performed.
SUSPENSION:REAR:AXLE:NON-POWERED AXLE ASSEMBLY
Volkswagen Group of America, Inc. (Audi) is recalling certain 2021 Q7, Q8, Q5 Sportback, SQ5 Sportback, RS6 Avant, RS7, RS Q8, 2020-2021 Audi S6 sedan, Q5, A8, S8, A7, A6 Allroad, A5 Cabriolet, A4 sedan, A4 Allroad, SQ5, S7, A6 sedan, S5 coupe, S4 sedan, S5 Cabriolet, A5 coupe, 2019-2021 RS5 coupe, A5 Sportback, S5 Sportback, RS5 Sportback vehicles. The lock nut on the trailing arm of the rear axle may break due to stress corrosion.
BACK OVER PREVENTION: SENSING SYSTEM: CAMERA
Volkswagen Group of America, Inc. (Audi) is recalling certain 2021 Audi A8 and S8, 2022 Audi A5 Sportback, A4 Sedan, E-Tron GT, Q3, Q5, RS6 Avant, A3 Sedan, S5 Sportback, Q5 Sportback, Q7, Q8, RSQ8, SQ7, SQ8, and S3 Sedan vehicles. A software error may prevent the rear-view image from initially displaying when the vehicle begins to reverse. As such, these vehicles fail to comply with the requirements of Federal Motor Vehicle Safety Standard number 111, "Rear Visibility."
ENGINE AND ENGINE COOLING:ENGINE:ENGINE CONTROL MODULE (ECU/ECM)
Volkswagen Group of America, Inc. (Audi) is recalling certain 2022 Audi A6 Sedan, A4 Sedan, Q5, and Q5 Sportback vehicles. The semiconductor inside the engine control unit may short-circuit and cause an engine stall.
+ 3 more recalls. Check all on NHTSA.gov
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Frequently Asked Questions
What are the most common Audi A4 problems?
According to Au7o's research across NHTSA recalls, manufacturer TSBs, and owner forum reports, the 2021 Audi A4 has 2 documented issues. The most frequently reported are: 2021-2022 A4 Rearview-Camera Software Recalls 91DZ / 91CR - VIN Check Required, 2009-2021 A4 2.0T Gasoline-Quality Deposit Diagnosis - TSB 2014753/13. Of these, 1 is rated critical and should be addressed promptly.
Is the Audi A4 reliable?
The 2021 Audi A4 has 2 known issues compiled from NHTSA recalls, manufacturer TSBs, and owner forum reports. 1 issue is rated critical: 2021-2022 A4 Rearview-Camera Software Recalls 91DZ / 91CR - VIN Check Required. Prospective buyers should inspect for these issues and factor potential repair costs into their purchase decision. Regular maintenance following the manufacturer's schedule helps prevent many common problems.
What is the 2021-2022 Audi A4 2021-2022 A4 Rearview-Camera Software Recalls 91DZ / 91CR - VIN Check Required?
NHTSA 22V742/Audi 91DZ covers certain 2021 A4 Sedan and A4 allroad vehicles, while NHTSA 21V825/Audi 91CR covers certain 2022 A4 Sedan vehicles. The rearview-camera image may be blank, black or initially unavailable when reverse is selected. The applicable population and software… Severity: high.
What is the 2009-2021 Audi A4 2009-2021 A4 2.0T Gasoline-Quality Deposit Diagnosis - TSB 2014753/13?
Audi states that contaminated gasoline or gasoline with insufficient deposit-control additives can contribute to deposits on intake valves, the intake manifold, fuel injectors and combustion chambers. Possible results include rough running after cold start, extended cranking, hes… Severity: medium.
Content on this page was compiled with AI assistance using NHTSA complaints, TSBs, owner reports, and public automotive data. While we strive for accuracy, this information may contain errors. Always verify repair procedures and specifications with your vehicle's service manual or a qualified mechanic.