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Audi A6 Allroad 2021 — Reported problems

Reported by owners to the source below. It is not a verdict on this car: it is what people wrote. 🇺🇸 Local data

27 owners reported problems with the 2021 Audi A6 Allroad to NHTSA, most often about electrical system.

All reports

27
EXTERIOR LIGHTING 2026-10-19 · NHTSA 11772117

Both daytime running lights have progressively changed from white to yellow and lost intensity. The discoloration began on one side and later appeared on the other, concentrated at the lower angled section of the daytime running light. There are no warning lamps, messages, or stored fault codes. Independent automotive lighting specialists who service this model describe the cause as heat from the daytime running light LED degrading the end of the clear light-guide tube inside the sealed headlamp assembly. The manufacturer does not sell that LED board or light guide separately, so the only available repair is replacement of the entire headlamp assembly. A manufacturer technical service bulletin covering this model and model year treats daytime running light color variation as a normal characteristic and states that no repair is to be performed, and no recall or warranty extension has been issued for this condition. The headlamps are available for inspection upon request. Safety risk: the daytime running lights are losing output and conspicuity gradually rather than failing outright, so the driver receives no warning and other road users see a vehicle with degraded daytime visibility.

ELECTRICAL SYSTEM,ENGINE,FUEL/PROPULSION SYSTEM 2026-09-21 · NHTSA 11765960

While operating the vehicle under normal driving conditions, the vehicle suffered an immediate, un-commanded loss of engine power and throttle response. The vehicle displayed a critical dashboard restriction stating: “Maximum engine speed 2500 RPM”, forcing an emergency limp-home mode that instantly created a roadway collision hazard. Simultaneously, the vehicle's primary safety and convenience systems dropped completely offline, displaying synchronized, consecutive malfunction alerts for the Central Locking System, Audi Pre Sense (Distance Monitoring), Cross Traffic Assist, and Lane Change/Blind Spot Warning systems. A subsequent professional diagnostic scan confirmed that the vehicle's Engine Control Unit (ECU) has hard-logged active manufacturer fault codes P310A (Low Fuel Pressure Regulation - Fuel Pressure Fluctuates) and P310B (Low Pressure Fuel Regulation - Fuel Pressure Outside Specification). These synchronized electrical and drivetrain failures occur intermittently, yet have specifically occurred multiple times following exposure to moisture, including rainfall, winter slush, and standard car washes. The identical electrical system dropouts were officially reported to two authorized Audi dealership service centers during its active warranty window, but the underlying system failures remain uncorrected, leaving a recurring safety hazard unaddressed.

ELECTRICAL SYSTEM 2026-09-04 · NHTSA 11762289

The vehicle went in for a software update. After purchasing the vehicle, the software update was part of a recall. Since that recall was performed, my vehicle has a lot of electronic glitches and a lot of issues. My external Morty just got done, paying 4500 to track down a central locking issue on top of the electronic issues. Did not fix the issue. I am out of town going to see family in California. The vehicle central locking air came back up. I could not get out of the vehicle lock and unlock went out work. Also, the door handles would not work me and my daughter had to climb out of the car windows to get out. So like, you know what? And then we had to try to access the battery compartment to do a hard reset. The vehicle is scheduled to go back to the manufacturer dealer to look at it again next week. However, I will be contacting audi u s a again. Since I told him I had all these issues, they refused to help me out in any way. This is a very big safety issue.

UNKNOWN OR OTHER 2026-05-15 · NHTSA 11738142

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 or dampers, likely caused by moisture accumulation and inadequate condensate drainage in the HVAC system. The vehicle was inspected and treated at an authorized Audi dealership; however, the treatment did not resolve the issue and the odor returned. Online owner forums and communities document the same problem across multiple Audi models and model years, suggesting this is a systemic design or manufacturing issue rather than an isolated incident. A passenger in the vehicle — a minor child with a documented mold allergy — has experienced allergic reactions as a result of exposure to the vehicle's air conditioning output. This constitutes a health and safety concern. The mold contamination in the HVAC system poses a risk to vehicle occupants, particularly those with respiratory conditions or mold sensitivities. I am requesting that NHTSA investigate whether a defect exists in the HVAC/evaporator system design across Audi vehicles, and whether a safety recall or technical service bulletin is warranted.

ENGINE AND ENGINE COOLING 2026-05-11 · NHTSA 11736958

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 with a coolant leak and a failed coolant pump vacuum. The contact was informed that the coolant pump vacuum assembly needed to be replaced. The vehicle was not repaired. In addition, the contact was informed that the failure was a known failure of the vehicle. The manufacturer was made aware of the failure and a case was filed. The contact was advised to contact the NHTSA Hotline and report the failure. The failure mileage was approximately 80,000.

ENGINE 2026-05-10 · NHTSA 11736875

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

POWER TRAIN 2026-04-09 · NHTSA 11730290

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 and no earlier incidence that led up to this issue. The vehicle is five years old with 39,834 miles and has had all routine maintenance and mileage interval services performed at the dealership, including its recent (Dec-25) 40,000-mile service. Thankfully this complete failure occurred when I was in my neighborhood and travelling 20mph; otherwise, the results could have been catastrophic had it occurred on a multilane highway at speeds of 65-70 MPH. The vehicle was towed to Audi of Indianapolis where the issue was identified as one broken bolt and two loose bolts for the transmission filter cap. This matches a known Audi Issue with a Technical Service Bulletin issued December 13, 2024, where they acknowledge a complete loss of power and a root cause of broken/loose bolts in the transmission filter. This is a known issue and is happening on low mileage well serviced vehicles. Because this issue is known and could result in a severe accident and/or loss of life under high-speed multi-lane highway conditions, it seems Audi of America should issue a recall versus just a TSB and/or extend the warranty for this issue up to 10 years or 100,000 miles which would, perhaps, be considered a normal lifespan for a part.

ELECTRICAL SYSTEM 2026-02-26 · NHTSA 11720755

My vehicle was excluded from Recall 25V20100/90VC; however, in early March 2025, it experienced the exact defect described in that recall: a complete failure of the instrument panel module. I paid $3,737.07 for the repair just weeks before the official recall began in late March 2025. I submitted a reimbursement claim to Audi of America under 49 CFR §573 and §577, including the paid invoice and all relevant documentation. Audi has since denied my claim. I am requesting your help to determine why my VIN was excluded from the known safety defect population. If my vehicle was not included, it suggests the recall may have been under-inclusive.

POWER TRAIN,ELECTRICAL SYSTEM 2026-02-24 · NHTSA 11720235

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 believe that! Bc dealer told me they pay if I fix it any where to get done quick bc was out stock

ELECTRICAL SYSTEM 2025-12-07 · NHTSA 11703548

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 no way to know my speed or see alerts. My VIN shows an open recall for this exact defect (instrument cluster blackout), but the failure has already happened during normal driving. I consider the vehicle unsafe to drive until repaired.

FORWARD COLLISION AVOIDANCE 2025-12-01 · NHTSA 11702177

The car has traffic sign recognition and uses it for "predictive control" where the vehicle will read traffic signs and adjust the adaptive cruise control setting to based on road signs. It had previously been working well but a software update was recently performed under TSB 2074688/3 on November 6th, 2025 and problems have shown up. Specifically, the system is incorrectly reading signs and sometimes appearing to make signs up out of nowhere. This has resulted in the car slowing down quickly on highways and nearly causing a couple of rear-end collisions due to the unexpected and erratic braking at highway speeds. The car will be going back to the dealer to be looked at, however this is unsafe because other drivers aren't prepared for a car randomly slowing down in front of them while on the highway for no reason. The car is also available to be inspected if needed. The issues first appeared within a week of having the TSB performed and has happened a number of times since. The following incidents have occurred: * Once on Highway 10 heading North/West between Big Lake and Elk River MN; the car was set to 60mph and hallucinated a 15mph speed limit sign. There was no speed limit sign on the road at all when this happened. This resulted in a near rear-end collision with the car behind. * Two times while on Highway 35E Southbound in the Minneapolis/St. Paul metro: 60mph to 40mph on clear roads. Once resulted in a near rear-end collision with the car behind. * Two times while on Highway 35E Northbound in the Minneapolis/St. Paul metro: 60mph to 40mph on clear roads * Once on Highway 35W Northbound in the Minneapolis/St. Paul metro: 60mph to 40mph on clear roads This software update is dangerous and should be updated or recalled, especially since the car did not have any issues of the sort prior to the update being performed.

FORWARD COLLISION AVOIDANCE 2025-08-13 · NHTSA 11680304

The Audi Pre-sense is activated by weather. I was driving during a thunderstorm and Audi Presence activated causing the car to come to a hard stop due to precipitation. It happened again backing out of my driveway the Audi Pre-sense was activated and the car came to a hard stop. I thought I had back into another vehicle. This is very dangerous.

ELECTRICAL SYSTEM 2025-06-27 · NHTSA 11669614

The Virtual Cockpit of the car (electronic screen right in front of the driver that displays speed, etc.) randomly turns off during driving, reboots, and displays an error message "Instrument Cluster Malfunction". A loud tone then chimes. This malfunction, while brief, is a safety issue due to the lack of speed information while driving.

ELECTRICAL SYSTEM,UNKNOWN OR OTHER,FORWARD COLLISION AVOIDANCE 2025-01-23 · NHTSA 11638013

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, continuous and mostly false warning lights are a driving distraction that can easily cause an accident. I have photos of all warning lights coming on in the vehicle. The dealership has repeated stated that they couldn't reproduce the problem even though pictures were provided and the car is still under the original warranty period. The latest attempt to fix the vehicle was to replace the sensors on the front of the vehicle. This solution was only attempted after the 4th report of the problem to the dealership where the car was serviced under the original manufacturers warranty

ELECTRICAL SYSTEM 2024-06-23 · NHTSA 11596019

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, the electrical system malfunction message became more severe and turned from yellow to red. While driving, the vehicle progressively shut down ABS, lane departure, and other systems and gave a transmission warning message. Eventually, the car lost power and I was left stranded at the side of the road.

ELECTRICAL SYSTEM 2023-10-10 · NHTSA 11549109

Notice of electronic failure on dash, then car notified me to pull over safely due to the failure after 20 min of driving. Car stopped shifting gears and electronic power steering failed while the vehicle was moving. Difficult to maneuver the car to safety once the Safely Pull Over light came on. 28,680 miles on the vehicle. Dealer stated the problem is the starter generator.

STEERING,ELECTRICAL SYSTEM,ENGINE 2023-09-09 · NHTSA 11543607

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 stop the car. After doing so and contacting the Audi roadside, the car was listing a series of issues on multiple symptoms while also saying in the warning message "still okay to drive". These systems included steering, braking, and what seemed to be other sensors the car powers. Finally (and within 5 minutes of the previous message of being okay to drive), the warnings were continuous and started including the transmission. The car stopped accelerating (we were on the expressway) and we thankfully got to the side of the road. This was an enormously dangerous situation as the car became fully disabled and we were subject to limited options of relief from a major traffic area. Within 30 minutes of being disabled, no electrical charge was present in the car, including emergency flashers, making the situation more dangerous as it was nighttime, so we had to abandon the car and walk down the expressway to find a hotel. Could not even put the car in neutral for the tow. Service is initially reporting a failure of the restart generator. This appears to be an alarmingly common issue with Audis.

ELECTRICAL SYSTEM 2023-06-05 · NHTSA 11525465

The contact owns a 2021 Audi A6. The contact stated while his father was driving 45 MPH, the electrical system Malfunction warning light illuminated. The contact stated that several electronic components started to turn off until the vehicle stalled. The vehicle was not drivable. The contact towed the vehicle to the local dealer, where it was diagnosed with needing the starter generator to be replaced. The vehicle was not repaired due to the parts being on backorder. The manufacturer had been informed of the failure. The failure mileage was approximately 38,000.

POWER TRAIN,ENGINE 2023-05-19 · NHTSA 11522924

At a highway speed of 50 MPH the transmission completely disengaged. I was driving on a busy highway with no shoulder. The vehicle continued to coast until I was forced to stop in an unsafe location. I placed the car in park, then in drive, and it was still disengaged. I needed to turn the car off, turn it on and it drove normally. Before I was able to bring it into Audi it occurred a second time on a bridge. I needed to perform the same steps (park, turn off, turn on) to begin driving again. Audi 'repaired' the vehicle. One month later it happened again. A service report cited this as a known issue. It created a significant risk to safety considering all events occurred at highway speed with no warning.

ELECTRICAL SYSTEM 2023-02-06 · NHTSA 11505775

The contact's wife owns a 2021 Audi A6. The contact received notification of NHTSA Campaign Number: 22V155000 (Electrical System) however, the part to do the recall repair was unavailable. The contact stated that the manufacturer had exceeded a reasonable amount of time for the recall repair. The manufacturer was contacted and was unable to confirm when parts would become available. The contact had not experienced a failure. VIN tool confirms parts not available.

ELECTRICAL SYSTEM 2023-01-17 · NHTSA 11502114

Multiple warnings indicating to contact dealer (Lane departure, adaptive cruise control, collision avoidance, electrical system, start/stop, etc) then 1 minute later transmission failure and engine failure imminent. After a minute or two my center MMI went blank then my electronic dash went blank, transmission went into neutral and the engine died all within a few seconds. Fortunately I was able to coast to a stop in the center median of an expressway and contacted the dealer. Flatbed towed to dealer who stated most likely the generator between the lithium battery bank and gas engine failed. They have seen several in this year for A6 and A7's with mild hybrid engines. I was lucky to be in low volume traffic as there was no power to indicate to drivers around me that my engine quit and not even turn signals worked. After having car towed to Audi dealer, they proceeded to tell me it was the starter/generator and the part was on back order for two to three months.

FUEL/PROPULSION SYSTEM 2022-12-01 · NHTSA 11495707

Audi has failed to come up with a repair for recall 22V742. My car consistently shows 1/4 tank of fuel when it’s actually near zero.

STRUCTURE 2022-09-22 · NHTSA 11485934

Sunroof spontaneously shattered while driving. No other cars around when this occurred. Caused a very loud BANG. Was driving on the freeway when this occurred. Dealer would not confirm issue was spontaneous - felt something must have hit the car to cause this. No defined impact location on roof. Also, roof glass was pushed up in the middle instead of down like would be expected if something hit it from the outside. No warning before it occurred.

ELECTRICAL SYSTEM,FUEL/PROPULSION SYSTEM 2022-09-01 · NHTSA 11482410

The car's fuel guage has been inaccurate since the initial purchase. It would always hang at around 50% and then drop to 5% within 10 miles. Thankfully, we are aware and just check the miles driven so we do not get stranded. Requested fix by dealership, they said there was nothing wrong. The recall for my car appeared and I asked for a fix, they said it's not available yet. It's been 6 months and there's still no fix for this. It would also have random computer issues such as screen shutdowns, and "take to dealership warnings" after the 1st 10k checkup. Had to bring back to the dealership, they replaced the entire computer. Seems to be fine, except a couple restarts. Back left seat is also damaged and would not lock into the upright position. Have not gone to dealership to fix yet as it will take time to buy parts and this is my only car.

FORWARD COLLISION AVOIDANCE 2022-07-30 · NHTSA 11476690

Today, I was in a protected left turn lane prior to making the turn. When oncoming traffic (4 lanes) cleared, I gently pressed the gas pedal to start the turn, but a red “pre-sense” error triggered and slammed on the brakes. I moved my foot to the brake and then back to the gas, and the error cleared, allowing me to continue the turn. This was dangerous as I could have stopped in front of oncoming traffic or been rear-ended by the car behind me. This is the first time I’ve had pre-sense braking engage, though I’ve gotten error messages while traveling at ~50mph in heavy traffic that’s it’s about to kick in. Several weeks ago, I made an appointment at my dealership to have the error messages looked at, but the first available appointment was about a month out, so I haven’t been able to take it in yet. In today’s incident, there was no warning before the braking engaged. I’m supportive of safety measures, but I am now scared of driving my car - I would rather have none of the fancy safety features than have false positives that put me in danger. This is like the Boeing 737 Max issue - why are cars with these issues allowed to be on the road??? Please make Audi fix this urgently, as message boards suggest it’s been an issue for at least five years!

ELECTRICAL SYSTEM 2022-04-07 · NHTSA 11460079

Liquid spulked in the trunk and somehow was able to get to the control module that is located under the rear seat similar concerns as recalled Audi Q5. Vehicle malfunctioned in the middle of a busy intersection.

STRUCTURE 2021-05-04 · NHTSA 11415078

DOORS MUST BE FORCEFULLY CLOSED IN ORDER TO FULLY LOCK. FREQUENTLY THE DOORS (ANY OF THE 4 ON THE CAR) DO NOT CLOSE UPON VEHICLE ENTRY. NO WARNING THAT THE DOOR IS NOT CLOSED IS PROVIDED BY THE VEHICLE. I HAVE DRIVEN MANY MILES WITH THIS UNSAFE CONDITION, ONLY TO DISCOVER THAT THE DOOR WAS NOT FULLY LATCHED UPON MY ARRIVAL AT MY DESTINATION. THE REAR HATCH ON THIS CAR ALSO SPONTANEOUSLY CLOSED DOWN ON ME WHEN I WAS LOADING PACKAGES INTO THE CARGO AREA. THE CAR IS EQUIPPED WITH HANDS-FREE HATCH OPENING WHICH ERRONEOUSLY INTERPRETED MY MOVEMENT WHILE LOADING THE PACKAGES AS A COMMAND TO CLOSE THE HATCH. THE SENSOR IS UNDER THE REAR BUMPER, CENTERED RIGHT WHERE ONE WOULD STAND WHILE LOADING THE CAR.

Specifications, safety and listings for this car

Questions

What do owners report most on the 2021 Audi A6 Allroad?
Problems with electrical system: 15 reports of 27 on record at NHTSA.
How many owner reports mention a crash or a fire?
Out of 27 reports: a crash is mentioned in 0 and a fire in 0. These are what owners wrote, not confirmed findings.