2021 Audi A7 Complaint Log

While driving on the freeway at approximately 65–70 mph, the engine suddenly stopped responding to all accelerator pedal inputs. The vehicle experienced an immediate, dangerous loss of motive power in active traffic. The dashboard displayed an amber check engine light alongside the central master warning light (an amber triangle with an exclamation point inside). I was forced to coast across active lanes of highway traffic to reach the right-hand shoulder. A State Trooper was on the shoulder and approached me, but there was no formal report. After turning the vehicle completely off and waiting, the system temporarily reset, and throttle response returned. The following day, the exact same sudden loss of accelerator response occurred while driving in local traffic, again creating a severe risk of a rear-end collision. The vehicle has been taken to an authorized Audi dealership for a diagnostic evaluation. No diagnostic trouble codes (DTCs) have been provided by the dealer yet. There was no crash or injury, but the sudden, repetitive loss of propulsion on a high-speed roadway constitutes an extreme safety hazard. I am the original owner and have maintained all scheduled maintenance intervals.

At approximately 43,044 miles, my 2021 Audi A7 55 TFSI e quattro (PHEV) was diagnosed with a failed N632 coolant changeover valve — a component of the PHEV thermal management heating circuit. The vehicle has a complete, documented service history with no maintenance gaps. The N632 is an electronically controlled valve that routes coolant between the combustion and hybrid/electric circuits and is essential for cabin heating in EV mode, battery pre-conditioning, and engine warm-up. Failure of this valve can result in loss of cabin heat, coolant leaks into the engine bay, and potential cascade of electrical faults if coolant migrates into the wiring harness. The repair estimate is $1,700. The factory warranty, Audi Care plan, and third-party extended service contract (United Car Care Protection Plus) have all denied coverage. This failure on a low-mileage PHEV with full service history suggests a premature component defect in Audi's PHEV thermal management system. I am requesting NHTSA investigate whether this constitutes a pattern of failure across 2021 Audi PHEV vehicles.

The first time, while driving at 50-55mph, the engine decelerated suddenly. After about 10-15 seconds struggles with the gas pedal and brake pedal, the car accelerated normally. I pulled safely to side of the road to shut off the engine and start again. Things seemed to work like normal. The control panels did not show any warning signs. The second and third times (couple weeks later), while driving around 40-45mph, the engine decelerated suddenly again. After some struggles like I did the first time, the engine accelerated like normal. Like the first time, the control panels did not display any warning signs. I took the car to the Audi dealer garage and they couldn't identify the problems. They performed two "engine software updates" and said hopefully it should address the engine decelerate issue. I was charged $299 for the diagnostic tests. I am worried what would happen if I was driving on a busy and highspeed Freeway!

Water pump design failure caused a leak of coolant into vacuum lines preventing coolant from cooling engine and causing immediate overheating. Known issue previous class action lawsuit.

The warning ‘drive system failure’ appears while driving and tells you to stop the car immediately. This happens randomly while driving on a highway. The engine now makes a higher pitched noise and then the transmission will no go into drive it immediately goes into neutral, the car slows down and you must pull over as you have no control over the car. The gas doesn’t work. There are so many alerts that pop up with a malfunction- parking brake, transmission, distance warning, audi presense warning, tire pressure malfunction, transmission malfunction. BEFORE this- There was an issue found when a check engine light appeared after the car failed emmissions testing. Control Pilot Circuit High and AC refrigerant pressor sensor B circuit failures listed. The car went to Audi and they said it was an air conditioning issue and other faults. The cleared the faults and signed off on the emmissions paperwork. I told Audi of the issue when getting it serviced- they could not replicate the random drive system failure alert. Again the same issue- bring it to audi- they had it for a week or so- still cannot replicate the issue. A few weeks later while driving on I91, the driver system alert comes on and there was a high pitched sound car goes into neutral- I have no control over the vehicle and coast down 2 roads and into a driveway of a volkswagen dealership in an unsafe area of Hartford. I then started the care up and took it to Audi of East Hartford. The replicated the issue they said and replaced the entire EOC unit for almost $7000. They had the car for a month. Then after having it back a couple of weeks it randomly does it again and restarting the car would reseg it only once and then another alert and the car dies on the highway and I again lose control and pull over to the shoulder. VERY VERY unsafe. The car just dies randomly on a highway. It happened in May of 2025, June and July. July 15 was the most recent immediately after being ‘repaired’.

At first, the yellow electrical system malfunction warning light came on. After a short time of driving, the light turned red, and very shortly after than (within five minutes as I was trying to drive the vehicle to the dealership for repair), all of the electrical systems in the vehicle failed. It created a very dangerous driving situation. I brought the vehicle to the Audi dealership, where they made repairs (replacing the generator) and returned the vehicle to me. Two days later, the yellow electrical system malfunction warning light returned while I was driving on the highway. I was able to drive the vehicle home, but along the way, the air conditioning failed. I will be bringing the vehicle back to Audi for further repairs. This defect is very dangerous because, in a very short amount of time, the car not only becomes inoperable, but essentially all of the car’s systems fail.

The virtual cockpit (dashboard) went completely black except for an exclamation point. Speed, warning symbols, engine temp etc were not visible. Dealers has confirmed the issue and is currently trying to remedy the situation. The danger was not knowing how fast I was traveling.

The contact owns a 2021 Audi A7. The contact stated while driving 70 MPH with the cruise control activated, the vehicle unexpectedly decelerated. The vehicle was taken to the dealer. The dealer informed the contact that the speed control software needed to be reprogrammed. The software was updated. The manufacturer was made aware of the failure but provided no assistance. The failure mileage was approximately 1,000.