NHTSA FEDERAL EVIDENCE AUDITAudited: 2026-08-25

2021 Audi A6 Common Problems & Defect Telemetry

Authoritative defect intelligence synthesized from 15 verified NHTSA owner complaints, 11 federal safety recalls, and interquartile failure mileage telemetry.

Data Grade: MEDIUM2 Odometer Verified EntriesMethodology
Executive AI Defect Summary

The 2021 Audi A6 receives a 6.5/10 MazicBay Reliability Index based on 15 verified NHTSA federal complaints and 11 safety recalls. The primary reported failure mode is Electrical Parasitic Drain, Infotainment & Harness Reports with a median failure point at 55,000 miles (IQR: 35,00075,000 mi). Out-of-warranty repairs benchmark at $280 – $850 .

2021 Audi A6Luxury2021
DLC Port: Driver lower dash trim near parking brake assembly

*Representative vehicle platform imagery. Body styling varies across generations.

MazicBay Reliability Index
6.5 / 10

12.5 complaints / 10k sold

NHTSA Owner Complaints
15

Verified US federal records

Safety Severity Grade
Low Risk

Crash, fire & stall audit

Federal Safety Recalls
11

11 Active / Free Remedies

Switch A6 Model Year (2014–2025)
Defect Clustering

Top Reported Problem Clusters (6)

Ranked by NHTSA Complaint Frequency
#1 ELECTRICAL SYSTEM & BATTERYMedium Severity87% Match Confidence

Electrical Parasitic Drain, Infotainment & Harness Reports

9
Federal Complaints
Failure Mileage (Median):55,000 milesIQR: 35,00075,000 mi
Estimated Repair Cost:$280 – $850 MazicBay Repair Intelligence Model
Recall Status:Out-of-Pocket / TSB RemedyNHTSA Campaign Audit
Reported Defect Symptoms
  • Unexplained battery drain after sitting overnight
  • Infotainment display / instrument cluster blackouts
  • Accessory malfunction / alternator fault warnings
Potentially Associated OBD-II Codes

Correlated via MazicBay Diagnostic Engine (not NHTSA verified fact).

Sample Verified NHTSA Evidence Records (3)
ODI #11720235 • Filed: 02/24/2026

My alternator was not working and it was a recall and I paid to fix it and they don’t wanna pay me back. I got a new part from audi and fix it at the shop and they don’t wanna pay anything just called and she said we don’t pay only if he’s done at the dealer. And I don’t belie...

ODI #11703548 • Filed: 12/07/2025

While driving at normal speed, the entire digital instrument panel suddenly went black and a red warning triangle appeared. I lost all gauges, including speedometer, fuel level, and warning indicators. This created a serious safety risk because I was in active traffic and had ...

ODI #11638013 • Filed: 01/23/2025

The car has had multiple issues with warning lights and malfunctioning systems. Including : 1.Child locks 2.Every single component of the ADAS 3. Emergency services being activated at least a few times a month - this is an SOS for emergency 911 service. The repeated, continuou...

#2 ENGINE & COOLINGMedium Severity71% Match Confidence

Engine Stalling, Oil Consumption & Cooling Defect Reports

6
Federal Complaints
Failure Mileage (Median):39,834 milesIQR: 39,83439,834 mi
Estimated Repair Cost:$950 – $3,200 MazicBay Repair Intelligence Model
Recall Status:Out-of-Pocket / TSB RemedyNHTSA Campaign Audit
Reported Defect Symptoms
  • Engine sudden stall / hesitation while driving
  • Abnormal oil burning / consumption
  • Check Engine Light (MIL) flashing
  • Engine overheating / coolant loss
Potentially Associated OBD-II Codes

Correlated via MazicBay Diagnostic Engine (not NHTSA verified fact).

Sample Verified NHTSA Evidence Records (3)
ODI #11738142 • Filed: 05/15/2026

My 2021 Audi A6 produces a strong mold and mildew odor from the HVAC/air conditioning system. The smell occurs consistently after the air conditioning is turned off and persists when entering the vehicle. The issue appears to originate from mold growth on the evaporator coil o...

ODI #11736958 • Filed: 05/11/2026

The contact owns a 2021 Audi A6. The contact stated while driving at an undisclosed speed, the vehicle overheated. The engine overheating and the low coolant warning light illuminated. In addition, the engine seized. The vehicle was taken to the dealer where it was diagnosed w...

ODI #11736875 • Filed: 05/10/2026

Thermostat housing and oil cooler bracket leaking coolant with only 56k miles on the car

#3 TRANSMISSION & DRIVETRAINMedium Severity68% Match Confidence

Transmission Hesitation, Hard Shifting & Slipping Reports

5
Federal Complaints
Failure Mileage (Median):39,834 milesIQR: 39,83439,834 mi
Estimated Repair Cost:$1,400 – $3,800 MazicBay Repair Intelligence Model
Recall Status:Out-of-Pocket / TSB RemedyNHTSA Campaign Audit
Reported Defect Symptoms
  • Hard gear shifts / delayed engagement into Drive/Reverse
  • Transmission shudder / jerking under acceleration
  • Transmission slipping between gears
Potentially Associated OBD-II Codes

Correlated via MazicBay Diagnostic Engine (not NHTSA verified fact).

Sample Verified NHTSA Evidence Records (3)
ODI #11730290 • Filed: 04/09/2026Odometer: 39,834 mi

I was driving my vehicle when the engine surged and then a transmission warning light came on and there was an immediate and complete loss of drive power. After the vehicle glided to a stop, there was no drive transmission in either forward or reverse. There was no pre-warning...

ODI #11720235 • Filed: 02/24/2026

My alternator was not working and it was a recall and I paid to fix it and they don’t wanna pay me back. I got a new part from audi and fix it at the shop and they don’t wanna pay anything just called and she said we don’t pay only if he’s done at the dealer. And I don’t belie...

ODI #11596019 • Filed: 06/23/2024

Vehicle had electrical system malfunction. Vehicle provided an electrical system malfunction and vehicle starting system malfunction warning message a few days prior to the incident. Vehicle has approximately 20.5K miles on odometer. Before I was able to bring it to service, t...

#4 STEERING & SUSPENSIONLow Severity69% Match Confidence

Electric Power Steering Assist & Suspension Noise Reports

2
Federal Complaints
Failure Mileage (Median):55,000 milesIQR: 35,00075,000 mi
Estimated Repair Cost:$450 – $1,400 MazicBay Repair Intelligence Model
Recall Status:Out-of-Pocket / TSB RemedyNHTSA Campaign Audit
Reported Defect Symptoms
  • Sudden loss of electric power steering assist
  • Steering wheel pull or highway wander
  • Clunking / knocking noise over bumps
Potentially Associated OBD-II Codes

Correlated via MazicBay Diagnostic Engine (not NHTSA verified fact).

Sample Verified NHTSA Evidence Records (2)
ODI #11736875 • Filed: 05/10/2026

Thermostat housing and oil cooler bracket leaking coolant with only 56k miles on the car

ODI #11543607 • Filed: 09/09/2023

Car reported an engine restarter issue (with battery symbol) and recommended to contact the dealer. Car next shut down automatic restart system, and air conditioning stopped working. Within a short period of time (same day), the car listed a red battery symbol and advised to s...

#5 BRAKING SYSTEM & ABSLow Severity65% Match Confidence

Service Brakes, ABS Actuator & Master Cylinder Reports

1
Federal Complaints
Failure Mileage (Median):55,000 milesIQR: 35,00075,000 mi
Estimated Repair Cost:$350 – $1,100 MazicBay Repair Intelligence Model
Recall Status:Out-of-Pocket / TSB RemedyNHTSA Campaign Audit
Reported Defect Symptoms
  • Spongy or hard brake pedal travel
  • ABS / Brake warning light illuminated
  • Extended stopping distance / pedal vibration
Potentially Associated OBD-II Codes

Correlated via MazicBay Diagnostic Engine (not NHTSA verified fact).

Sample Verified NHTSA Evidence Records (1)
ODI #11596019 • Filed: 06/23/2024

Vehicle had electrical system malfunction. Vehicle provided an electrical system malfunction and vehicle starting system malfunction warning message a few days prior to the incident. Vehicle has approximately 20.5K miles on odometer. Before I was able to bring it to service, t...

#6 AIRBAGS & SAFETY RESTRAINTSLow Severity65% Match Confidence

Airbag Occupant Detection & Inflator Defect Reports

1
Federal Complaints
Failure Mileage (Median):55,000 milesIQR: 35,00075,000 mi
Estimated Repair Cost:$400 – $1,200 MazicBay Repair Intelligence Model
Recall Status:Out-of-Pocket / TSB RemedyNHTSA Campaign Audit
Reported Defect Symptoms
  • SRS Airbag warning lamp illuminated
  • Passenger occupant classification sensor failure
  • Seat belt retractor lockup
Potentially Associated OBD-II Codes

Correlated via MazicBay Diagnostic Engine (not NHTSA verified fact).

Sample Verified NHTSA Evidence Records (1)
ODI #11738142 • Filed: 05/15/2026

My 2021 Audi A6 produces a strong mold and mildew odor from the HVAC/air conditioning system. The smell occurs consistently after the air conditioning is turned off and persists when entering the vehicle. The issue appears to originate from mold growth on the evaporator coil o...

Safety Enforcement

Official NHTSA Safety Recalls (11)

100% Free Dealer Repair
NHTSA Campaign #21V606000Reported: 05/08/2021

SEAT BELTS:REAR/OTHER:RETRACTOR

Summary: 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."

Safety Consequence: An unsecured child restraint system can increase the risk of injury during a crash.
Manufacturer 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).
NHTSA Campaign #22V034000Reported: 26/01/2022

TIRES

Summary: 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.

Safety Consequence: Rear axle misalignment may cause premature or uneven tire wear, increasing the risk of a crash.
Manufacturer Remedy: Dealers will inspect the rear axle, adjust the alignment as necessary, and replace any prematurely or unevenly worn tires, free of charge. Owner notification letters were mailed March 3, 2022. Owners may contact Audi customer service at 1-800-253-2834. Audi's number for this recall is 42L5.
NHTSA Campaign #21V159000Reported: 10/03/2021

AIR BAGS

Summary: Volkswagen Group of America, Inc. (Audi) is recalling certain 2021 Audi RS6 Avant, RS7, 2020-2021 A6 Allroad, S6 Sedan, S7, 2019-2021 A6 Sedan, and A7 vehicles. The score line on the passenger air bag may not have been manufactured correctly.

Safety Consequence: An incorrectly manufactured air bag may not deploy properly, and could also eject plastic debris into the passenger compartment, increasing the risk of injury during a crash.
Manufacturer Remedy: Audi will notify owners, and dealers will inspect the passenger air bag score line, and repair it as necessary, free of charge. The recall begin March 26, 2021. Owners may contact Audi customer service at 1-800-253-2834. Audi's number for this recall is 70i2.
NHTSA Campaign #20V749000Reported: 02/12/2020

ELECTRICAL SYSTEM

Summary: Volkswagen Group of America, Inc. (Audi) is recalling certain 2021 Audi A6 Allroad, Q7, RS6 and RS7 vehicles. The electrical connector can detach from the door crash sensor in either of the front doors.

Safety Consequence: A detached connector can delay the activation of the restraint systems, including the side air bag, curtain air bag and/or seat-belt pretensioners during a side impact crash, increasing the risk of injury.
Manufacturer Remedy: Audi will notify owners, and dealers will inspect, and as necessary, replace the crash sensors in both front doors, free of charge. The recall began December 23, 2020. Owners may contact Audi customer service at 1-800-253-2834. Audi's number for this recall is 69BM.
NHTSA Campaign #21V295000Reported: 26/04/2021

SUSPENSION:REAR:AXLE:NON-POWERED AXLE ASSEMBLY

Summary: 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.

Safety Consequence: A broken lock nut may misalign the rear axle, causing a loss of control and increasing the risk of a crash.
Manufacturer 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.
NHTSA Campaign #22V155000Reported: 14/03/2022

ELECTRICAL SYSTEM:INSTRUMENT PANEL:FUEL GAUGE:FUEL LEVEL FLOAT/SENSOR/SENDING UNIT

Summary: Volkswagen Group of America, Inc. (Audi) is recalling certain 2021-2022 RS6 Avant and RS7, 2020-2022 A6 Allroad, S6 Sedan, and S7, and 2019-2022 A6 Sedan and A7 vehicles. The fuel level sender may stick, causing an inaccurate fuel level reading to be displayed on the instrument cluster.

Safety Consequence: An inaccurate fuel reading may cause an engine stall due to lack of fuel, increasing the risk of a crash.
Manufacturer Remedy: Dealers will install a new sensor in the tank, free of charge. Owner notification letters were mailed February 17, 2023. Owners may contact Audi customer service at 1-800-253-2834. Audi's number for this recall is 20DN.
NHTSA Campaign #22V742000Reported: 05/10/2022

BACK OVER PREVENTION:DISPLAY FUNCTION

Summary: 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."

Safety Consequence: A blank rearview camera display can reduce the driver's rear visibility, increasing the risk of a crash.
Manufacturer 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.
NHTSA Campaign #22V861000Reported: 21/11/2022

ELECTRICAL SYSTEM

Summary: Volkswagen Group of America, Inc. (Audi) is recalling certain 2020-2022 Audi S7, S6 Sedan, A6 Allroad, 2021-2022 RS7, RS6 Avant, 2019-2022 A7, and A6 Sedan vehicles. Liquid spilled in the rear seat may penetrate and cause the gateway control module to shut down.

Safety Consequence: A gateway control module shutdown will suddenly reduce engine power, increasing the risk of a crash.
Manufacturer Remedy: Dealers will install a protective cover, free of charge. Owner notification letters are expected to be mailed January 20, 2023. Owners may contact Audi's customer service at 1-800-253-2834. Audi's number for this recall is 90V2.
NHTSA Campaign #23V601000Reported: 25/08/2023

SERVICE BRAKES, HYDRAULIC:FLUID

Summary: Volkswagen Group of America, Inc. (Audi) is recalling certain 2021 Audi S7, S6 Sedan, RS7, RS6 Avant, A6 Allroad, 2019-2021 A7, and A6 Sedan vehicles. An incorrectly labeled brake fluid cap may have been installed, which can result in the use of the wrong type of brake fluid.

Safety Consequence: Incorrect brake fluid can reduce braking ability and increase the risk of a crash.
Manufacturer Remedy: Dealers will inspect the brake fluid reservoir cap and, if necessary, replace it, free of charge. Owner notification letters are expected to be mailed October 17, 2023. Owners may contact Audi's customer service at 1-800-253-2834. Volkswagen's number for this recall is 47T9.
NHTSA Campaign #25V201000Reported: 31/03/2025

ELECTRICAL SYSTEM: INSTRUMENT CLUSTER/PANEL

Summary: Volkswagen Group of America, Inc. (Audi) is recalling certain 2021 SQ8, A6 SEDAN, A7, A8, Q7, Q8, RS6 Avant, RS7, RSQ8, S6 SEDAN, S7, S8, A6 Allroad, and SQ7 vehicles. Due to a software error, the instrument panel display may fail.

Safety Consequence: An instrument panel display that fails to show critical safety information, such as the speedometer or warning lights, increases the risk of a crash.
Manufacturer Remedy: Dealers will update the instrument panel module software, free of charge. Owner notification letters were mailed April 24, 2025. Owners may contact Audi customer service at 1-800-253-2834. Audi's number for this recall is 90VC.
NHTSA Campaign #25V900000Reported: 19/12/2025

BACK OVER PREVENTION: SENSING SYSTEM: CAMERA

Summary: Volkswagen Group of America, Inc. (Audi) is recalling certain 2019-2026 vehicles. Please see the recall report for a complete list of models. A software error may prevent the rearview camera image from displaying as intended. As such, these vehicles fail to comply with the requirements of Federal Motor Vehicle Safety Standard number 111, "Rear Visibility."

Safety Consequence: A rearview image that does not display reduces the driver's view behind the vehicle, increasing the risk of a crash.
Manufacturer Remedy: Dealers will update the software, free of charge. Owner notification letters were mailed January 14, 2026. Owners may contact Audi customer service at 1-800-253-2834. Audi's number for this recall is 90TV. Vehicle Identification Numbers (VINs) involved in this recall became searchable on NHTSA.gov on December 23, 2025.

Pre-Purchase Inspection Checklist for 2021 Audi A6

Before purchasing a used 2021 Audi A6, perform the following targeted inspections based on reported federal defect patterns:

1. Cold Start & Idle Diagnostics

Scan the OBD-II port under the dash for pending freeze-frame codes (e.g. P0300 misfires, P0087 fuel rail pressure, P0420 catalytic efficiency).

2. Transmission Shift Quality Audit

Test vehicle at low-speed stop-and-go and highway merges. Check for delayed reverse engagement or gear shift shudder between 2nd and 3rd gears.

3. Federal Recall Completion Check

Verify that all 11 NHTSA safety recall campaigns have been performed by an authorized dealership using the VIN.

4. Electrical & Infotainment Drain Check

Ensure the instrument cluster, center screen, and auxiliary charging ports operate with stable 12.0V–14.4V alternator voltage.

Frequently Answered Questions

Defect & Reliability Q&A: 2021 Audi A6

Is the 2021 Audi A6 a reliable used car?

The 2021 Audi A6 earns a 6.5/10 MazicBay Reliability Index based on 15 federal owner reports. Vehicles maintained under factory service schedules exhibit strong longevity past 150,000 miles.

What is the most frequent defect reported on the 2021 Audi A6?

The leading complaint category is Electrical Parasitic Drain, Infotainment & Harness Reports, with a median failure point around 55,000 miles (IQR: 35,00075,000 mi).

Are there free recall repairs available for the 2021 Audi A6?

Yes, the NHTSA records 11 safety recall campaign(s) for this model year. All safety recalls are performed 100% free of charge by authorized franchise dealerships regardless of vehicle warranty status.