2021 Audi A4 Problems and Recalls

Source: NHTSA vehicle records, recall and complaint snapshot 2026-10-18. Manufacturer communications retain their separately dated source snapshot. Counts are submitted records, not failure probabilities. One vehicle can appear in several campaigns.

Complaint model names counted: A4, A4 ALLROAD. Recall model names counted: A4, A4 ALLROAD. Complaint records are deduplicated by ODI number; vehicle recalls are counted by distinct campaign number for this year.

Model-year records

What the 2021 record can and cannot say

The 2021 record contains 12 submitted complaints. The median across this model's matched years is 13 reports. Neither number accounts for vehicle sales or time on the road. Source names: A4, A4 ALLROAD. NHTSA source snapshot: 2026-10-18.

Electrical System is the most common displayed component tag, with 3 reports (25% of this year's submitted complaints). One complaint can name several components. The share describes reports, not the probability of a failure.

Engine replacement or major internal repair has the highest arithmetic midpoint for parts in the applicable planning estimates, at $8,000 before labor. A paid plan can help only if the component and cause qualify; check existing manufacturer coverage first.

Problem research and repair guidance

2021 Audi A4: symptoms, affected vehicles and documented fixes

Match the symptom and the exact vehicle scope before arranging work. The imported catalogue is an editorial index of source documents, not an independent safety authority. Recall text is checked against NHTSA; each record links to the evidence that supports its scope and remedy.

3documented issue files

3vehicle systems

3 recall files · 0 other manufacturer files. These are editorial file counts, not distinct campaign totals, failure rates or a complete recall history.

BACK OVER PREVENTION

Official safety recall2021Campaign 22V742000

BACK OVER PREVENTION:DISPLAY FUNCTION: recall 22V742000

A blank rearview camera display can reduce the driver's rear visibility, increasing the risk of a crash.

Volkswagen Group of America, Inc. (Volkswagen) is recalling certain 2021 Audi A8, RS7, RS6 Avant, RS5 Sportback, RS5 Coupe, Q8, Q7, Q5 Sportback, S4 Sedan, Q5, A7, A6, A6 Allroad, A5 Sportback, A5 Coupe, A5 Cabrioleet, A4 Sedan, A4 Allroad, E-Tron Sportback Quattro, SQ7, S5 Cabriolet, E-Tron Quattro, SQ8, SQ5 Sportback, SQ5, S8, S7, S6 Sedan, S5 Sportback, S5 Coupe, 2022 E-Tron GT, and 2021-2022 RSQ8 vehicles. Due to a software issue, a blank or black screen may be displayed instead of the rearview camera image when the vehicle is placed in reverse gear. As such, these vehicles fail to comply with the requirements of Federal Motor Vehicle Safety Standard number 111, "Rear Visibility."

Condition in the official record

Volkswagen Group of America, Inc. (Volkswagen) is recalling certain 2021 Audi A8, RS7, RS6 Avant, RS5 Sportback, RS5 Coupe, Q8, Q7, Q5 Sportback, S4 Sedan, Q5, A7, A6, A6 Allroad, A5 Sportback, A5 Coupe, A5 Cabrioleet, A4 Sedan, A4 Allroad, E-Tron Sportback Quattro, SQ7, S5 Cabriolet, E-Tron Quattro, SQ8, SQ5 Sportback, SQ5, S8, S7, S6 Sedan, S5 Sportback, S5 Coupe, 2022 E-Tron GT, and 2021-2022 RSQ8 vehicles. Due to a software issue, a blank or black screen may be displayed instead of the rearview camera image when the vehicle is placed in reverse gear. As such, these vehicles fail to comply with the requirements of Federal Motor Vehicle Safety Standard number 111, "Rear Visibility."

Which vehicles the source covers

NHTSA model names: A4. Model years: 2021.
NHTSA campaign 22V742000
The complete campaign lists 170,296 potentially affected units across all listed vehicles.
A make, model and year match does not establish VIN eligibility.

Safety recall eligibility is based on the VIN and campaign scope, not ordinary warranty mileage. Check the complete VIN even when the vehicle is outside its original warranty.

Component in the source: BACK OVER PREVENTION:DISPLAY FUNCTION

Published recall remedy

Dealers will update the infotainment unit software, free of charge. Owner notification letters were mailed October 25, 2022. Owners may contact Audi's customer service at 1-800-253-2834. Volkswagen's number for this recall is 91DZ.

Consequence in the NHTSA record: A blank rearview camera display can reduce the driver's rear visibility, increasing the risk of a crash.

Official recall remedyManufacturer or authorized dealer · Confirm with the dealer

Dealers will update the infotainment unit software, free of charge. Owner notification letters were mailed October 25, 2022. Owners may contact Audi's customer service at 1-800-253-2834. Volkswagen's number for this recall is 91DZ.

Limit: Confirm VIN eligibility and current remedy instructions with the manufacturer.

Check the complete VINVIN lookup · Before arranging repairs

Check the 17-character VIN at NHTSA.gov/recalls and ask the manufacturer whether this campaign remains open for the vehicle.

Limit: The model-year list is not proof that an individual vehicle is affected.

Evidence for this issue

22V742000: NHTSA campaign 22V742000
NHTSA safety recall · 2022-10-05
Official component, defect, consequence and remedy; checked 2026-10-18.

Open this problem file →

Source review: 2026-10-18

SEAT BELTS

Official safety recall2021Campaign 21V606000

SEAT BELTS:REAR/OTHER:RETRACTOR: recall 21V606000

An unsecured child restraint system can increase the risk of injury during a crash.

Volkswagen Group of America, Inc. (Volkswagen) is recalling certain 2021 Volkswagen ID4, Audi A4 Allroad, A4 Sedan, A5 Cabriolet, A5 Coupe, A5 Sportback, A6 Allroad, A6 Sedan, A7, A8, E-Tron Quattro, E-Tron Sportback Quattro, Q3, Q5, Q5 Sportback, Q7, Q8, RS5 Sportback, RS5 Coupe, RS6 Avant, RS7, RSQ8, S4 Sedan, S5 Cabriolet, S5 Coupe, S5 Sportback, S6 Sedan, S7, S8, SQ5, SQ5 Sportback, SQ7, SQ8, and 2021-2022 S3 Sedan vehicles. The rear seat belt automatic locking retractors may deactivate early, which can prevent the child restraint system from securing properly. As such, these vehicles fail to comply with the requirements of Federal Motor Vehicle Safety Standard number 208, "Occupant Crash Protection."

Condition in the official record

Volkswagen Group of America, Inc. (Volkswagen) is recalling certain 2021 Volkswagen ID4, Audi A4 Allroad, A4 Sedan, A5 Cabriolet, A5 Coupe, A5 Sportback, A6 Allroad, A6 Sedan, A7, A8, E-Tron Quattro, E-Tron Sportback Quattro, Q3, Q5, Q5 Sportback, Q7, Q8, RS5 Sportback, RS5 Coupe, RS6 Avant, RS7, RSQ8, S4 Sedan, S5 Cabriolet, S5 Coupe, S5 Sportback, S6 Sedan, S7, S8, SQ5, SQ5 Sportback, SQ7, SQ8, and 2021-2022 S3 Sedan vehicles. The rear seat belt automatic locking retractors may deactivate early, which can prevent the child restraint system from securing properly. As such, these vehicles fail to comply with the requirements of Federal Motor Vehicle Safety Standard number 208, "Occupant Crash Protection."

Which vehicles the source covers

NHTSA model names: A4. Model years: 2021.
NHTSA campaign 21V606000
The complete campaign lists 45,496 potentially affected units across all listed vehicles.
A make, model and year match does not establish VIN eligibility.

Safety recall eligibility is based on the VIN and campaign scope, not ordinary warranty mileage. Check the complete VIN even when the vehicle is outside its original warranty.

Component in the source: SEAT BELTS:REAR/OTHER:RETRACTOR

Published recall remedy

Dealers will inspect, and replace as necessary, the middle-rear seat belt assemblies, free of charge. Owner notification letters were mailed August 27, 2021. Owners may contact Volkswagen customer service at 1-800-893-5298 and Audi customer service at 1-800-253-2834. Volkswagen's numbers for this recall are 69CR (VW) and 69CS (Audi).

Consequence in the NHTSA record: An unsecured child restraint system can increase the risk of injury during a crash.

Official recall remedyManufacturer or authorized dealer · Confirm with the dealer

Dealers will inspect, and replace as necessary, the middle-rear seat belt assemblies, free of charge. Owner notification letters were mailed August 27, 2021. Owners may contact Volkswagen customer service at 1-800-893-5298 and Audi customer service at 1-800-253-2834. Volkswagen's numbers for this recall are 69CR (VW) and 69CS (Audi).

Limit: Confirm VIN eligibility and current remedy instructions with the manufacturer.

Check the complete VINVIN lookup · Before arranging repairs

Check the 17-character VIN at NHTSA.gov/recalls and ask the manufacturer whether this campaign remains open for the vehicle.

Limit: The model-year list is not proof that an individual vehicle is affected.

Evidence for this issue

21V606000: NHTSA campaign 21V606000
NHTSA safety recall · 2021-08-05
Official component, defect, consequence and remedy; checked 2026-10-18.

Open this problem file →

Source review: 2026-10-18

SUSPENSION

Official safety recall2020, 2021Campaign 21V295000

SUSPENSION:REAR:AXLE:NON-POWERED AXLE ASSEMBLY: recall 21V295000

A broken lock nut may misalign the rear axle, causing a loss of control and increasing the risk of a crash.

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.

Condition in the official record

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.

Which vehicles the source covers

NHTSA model names: A4. Model years: 2020, 2021.
NHTSA campaign 21V295000
The complete campaign lists 40,993 potentially affected units across all listed vehicles.
A make, model and year match does not establish VIN eligibility.

Safety recall eligibility is based on the VIN and campaign scope, not ordinary warranty mileage. Check the complete VIN even when the vehicle is outside its original warranty.

Component in the source: SUSPENSION:REAR:AXLE:NON-POWERED AXLE ASSEMBLY

Published recall remedy

Dealers will replace the lock nuts and, if necessary, the associated bolts, free of charge. Owner notification letters were mailed June 4, 2021. Owners may contact Audi customer service at 1-800-253-2834. Audi's number for this recall is 42L1.

Consequence in the NHTSA record: A broken lock nut may misalign the rear axle, causing a loss of control and increasing the risk of a crash.

Official recall remedyManufacturer or authorized dealer · Confirm with the dealer

Dealers will replace the lock nuts and, if necessary, the associated bolts, free of charge. Owner notification letters were mailed June 4, 2021. Owners may contact Audi customer service at 1-800-253-2834. Audi's number for this recall is 42L1.

Limit: Confirm VIN eligibility and current remedy instructions with the manufacturer.

Check the complete VINVIN lookup · Before arranging repairs

Check the 17-character VIN at NHTSA.gov/recalls and ask the manufacturer whether this campaign remains open for the vehicle.

Limit: The model-year list is not proof that an individual vehicle is affected.

Evidence for this issue

21V295000: NHTSA campaign 21V295000
NHTSA safety recall · 2021-04-26
Official component, defect, consequence and remedy; checked 2026-10-18.

Open this problem file →

Source review: 2026-10-18

Confirm who pays before authorizing work

A recall remedy follows the campaign and VIN eligibility. A service bulletin provides diagnosis or repair instructions; it does not by itself promise payment. Manufacturer warranty extensions and support programs have their own conditions.

Compare recalls, bulletins and warranty extensions →

Keep a current problem separate from future coverage

These files do not supply a shop quote. Ask for a diagnosis and written estimate, then check recall remedies or existing coverage. A new vehicle service contract generally excludes pre-existing conditions.

Prepare a useful description for the mechanic →

Each file retains its original source review date. Historical remedy wording can change; check the current manufacturer notice and NHTSA VIN lookup for your vehicle. The separately dated NHTSA counts elsewhere on this page use a different dataset and scope.

Read the evidence for this vehicle

What can the data tell you about 2021 Audi A4?

No model-specific individual-repair price keys are retained for Audi A4 in this library. Generic parts and labor estimates, public records and separate annual cost references may still be available.

Individual-repair price scopeGeneric inputs

Model-level range presence is a source-coverage check. It does not confirm that a repair fits every engine or model year.

EPA configuration match3 source rows

This model year can include different equipment. Use the VIN and original specifications to identify the actual configuration.

Documented repair pathsCheck the source

Recall and communication counts describe records. They cannot establish a breakdown probability or current VIN status.

Price-key audit reviewed October 18, 2026; EPA source snapshot 2026-08-07. Individual-repair ranges and annual repair-budget references are different datasets.

Cost-library audit

The evidence behind a repair estimate

30 of 44 repair categories have verified national benchmarks; 14 retain planning assumptions. Old model-specific ranges were removed because this refresh did not reverify them.

44 repair categories; a content audit, not a market survey

See the analysis, charts and method →

Campaign-reference audit

One campaign can create many entries

1,200 selected recall files resolve to 780 distinct campaign IDs after compact references are normalized and checked against official NHTSA records. Files and campaigns are different counting units.

1200 selected recall files; normalized references checked against official NHTSA records

See the analysis, charts and method →

Source: NHTSA vehicle records, recall and complaint snapshot 2026-10-18. Manufacturer communications retain their separately dated source snapshot. Counts are submitted records, not failure probabilities. One vehicle can appear in several campaigns.

Complaint model names counted: A4, A4 ALLROAD. Recall model names counted: A4, A4 ALLROAD. Complaint records are deduplicated by ODI number; vehicle recalls are counted by distinct campaign number for this year.

Sources and methods

What each source tells you

NHTSA records: 12 submitted complaints, 4 recalls and 1,033 manufacturer communications. These are report counts, not failure probabilities.

EPA vehicle details: 3 matched fuel-economy configurations help us leave out repairs for equipment this model year does not have.

Repair-cost estimates: We model 33 applicable repairs beyond normal wear items, using published benchmarks where available plus parts and independent-shop labor assumptions. These ranges are not dealer quotes, repair-shop quotes or invoices.

Read the full research and repair-cost methodology.

Vehicle configuration

2021 EPA specification range

The official dataset contains 3 matched configurations for this model year. The range reflects trim and drivetrain choices, not changes to the complaint count.

Vehicle classCompact car and Small station wagon

Fuel choicesHybrid

Drive layoutsAll-wheel drive

Engine range2 L; 4 cylinders

EPA efficiency26 to 28 mpg

Transmission typesAutomatic

EPA figures vary by configuration. Confirm the exact engine, drive layout and fuel system from the VIN or original window sticker. Source: FuelEconomy.gov vehicle data, updated 2026-08-07.

Estimated repair bills

Major repair cost range

These ranges combine parts and labor benchmarks with modeled independent-shop rates for 50-metro reference. These are national repair benchmarks and planning assumptions, not published prices for this exact vehicle. We filter repairs using the available model-year specifications; a shop must confirm the engine, equipment and diagnosed job.

Repair	System	Estimated range
Engine replacement or major internal repair	Engine	$6,095 to $16,964
Transmission replacement	Transmission	$6,079 to $6,995
Transfer case replacement	Driveline	$2,189 to $8,192
Hybrid high voltage battery replacement	Hybrid powertrain	$4,797 to $5,140
Turbocharger replacement	Turbo and Supercharger	$1,662 to $6,524
Head gasket replacement	Engine	$2,339 to $3,728
Strut and control arm repair	Suspension	$1,053 to $4,545
Fuel injector set replacement	Fuel System	$908 to $4,651
Infotainment display or head unit replacement	Electrical and Electronic	$722 to $4,467
Timing chain replacement	Engine	$1,934 to $3,038

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$6,095-$16,964 largest modeled range shownEstimated repair cost, not a shop quote or a prediction.

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Compare years

Other Audi A4 model years

2026Not available reports · Not available recalls 20251 reports · 0 recalls 20246 reports · 0 recalls 202311 reports · 1 recalls 20227 reports · 3 recalls 202112 reports · 4 recalls 2020158 reports · 3 recalls 201913 reports · 1 recalls 201854 reports · 4 recalls 201786 reports · 6 recalls 201626 reports · 3 recalls 201544 reports · 4 recalls

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Is an Extended Warranty Worth It for a 2021 Audi A4?

What the 2021 record can and cannot say

Follow or share this source snapshot

2021 Audi A4: symptoms, affected vehicles and documented fixes

BACK OVER PREVENTION

BACK OVER PREVENTION:DISPLAY FUNCTION: recall 22V742000

Condition in the official record

Which vehicles the source covers

Published recall remedy

Evidence for this issue

SEAT BELTS

SEAT BELTS:REAR/OTHER:RETRACTOR: recall 21V606000

Condition in the official record

Which vehicles the source covers

Published recall remedy

Evidence for this issue

SUSPENSION

SUSPENSION:REAR:AXLE:NON-POWERED AXLE ASSEMBLY: recall 21V295000

Condition in the official record

Which vehicles the source covers

Published recall remedy

Evidence for this issue

Confirm who pays before authorizing work

Keep a current problem separate from future coverage

What can the data tell you about 2021 Audi A4?

The evidence behind a repair estimate

One campaign can create many entries

What each source tells you

2021 EPA specification range

Major repair cost range

Other Audi A4 model years