AUDI A6 Allroad Reliability by YearBest & worst years, problems & recalls — NHTSA data

I have a 2020 All Road. Received message driving close to my home to contact service due to electrical malfunction and made it to my driveway. This was on a Sunday and no service center was available. Car lost its HVAC and auto stop mechanism on the way home and parked it in the driveway away to be towed. This morning able to start vehicle but received numerous warnings as above to also include low battery due to no charging and finally a message (while placing it on a flat bed tow truck) to stop immediately and not drive the vehicle. I have read about disasters with this issue in regards to innumerable complaints from new Audi owners that this occurred very quickly while driving on an interstate in which their vehicle shut down within a minute and those affected experienced total loss of steering and braking with inability to even turn on their flashers for safety purposes. This is not a benign issue as beyond the inconvenience of waiting hours to be towed, one puts their life at risk when traveling on an interstate and within seconds having such a shut down of the vehicle occur. I am glad that I did not drive the vehicle in for servicing as I'd likely be on an interstate stranded at this time or perhaps even injured or dead due to inability to control the vehicle and a shut down occurring with only a few seconds notice. I am aware that several TSBs exist for this problem likely related to a faulty alternator as part of internal combustion machines using a "mild hybrid" system. Audi should do a recall of all such vehicles affected with this technology but instead utilizes an approach of reliance upon their dealerships. I have heard of weeks to months to replace alternators / 48 V battery as such parts come from Germany. This is a SERIOUS life threatening issue that puts one at risk of losing control at high speed or getting hit from behind on an interstate due to complete failure of the vehicle and inability to control it after achieving speed.

Lamp: Electrical system malfunction: safely stop vehicle. I have read that they car would have next shut down and loss of control while driving.

While driving on the interstate, I received a warning about an electrical system malfunction. As I neared my home, I received warnings about transmission failure, suspension malfunction, steering malfunction, sensor failure, and more. After a tow to the dealership I was told it is a generator/alternator (?) failure and the part is on national backorder and may be 3 months or more.

My electrical system failed and the car died on the freeway. This is now recognized as a chronic problem- a software bug in the 48 volt mild hybrid system- with several Audi models, including this A6 Allroad. The bug apparently damages the vehicles alternator, which must then be replaced. There is a several month backorder on this part, so hundreds if not thousands Audis remain unrepaired on the lots. They are dying on roads across the USA on a daily basis.

The contact's wife owns a 2020 Audi A6. The vehicle was serviced under NHTSA Campaign Number: 21V295000 (suspension), however after a few months the contact had an issue with the vehicle's rear tires. The vehicle was taken to a tire center where they were unable to replace the rear tires due to severe damage to the undercarriage and rear axle on the vehicle. The local dealer who performed the recall repair was called but told over the phone that the dealer does not have any record in their system showing they performed that recall repair on the vehicle despite the contact having the work order detailing the repair. The vehicle was not repaired. The manufacturer was not made aware of the failure. The failure was mileage was approximately 9,027.

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.

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.

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

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.

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.

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

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.

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.

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.