2021 Audi A4 Common Problems & Defect Telemetry
Authoritative defect intelligence synthesized from 11 verified NHTSA owner complaints, 4 federal safety recalls, and interquartile failure mileage telemetry.
The 2021 Audi A4 receives a 4.5/10 MazicBay Reliability Index based on 11 verified NHTSA federal complaints and 4 safety recalls. The primary reported failure mode is Electrical Parasitic Drain, Infotainment & Harness Reports with a median failure point at 55,000 miles (IQR: 35,000 – 75,000 mi). Out-of-warranty repairs benchmark at $280 – $850 .
6.1 complaints / 10k sold
Verified US federal records
Crash, fire & stall audit
4 Active / Free Remedies
Top Reported Problem Clusters (6)
Electrical Parasitic Drain, Infotainment & Harness Reports
- Unexplained battery drain after sitting overnight
- Infotainment display / instrument cluster blackouts
- Accessory malfunction / alternator fault warnings
“The instrument cluster has stop working. Have to monitore vehicle information, Mileage, service, Safty notifications and general vehicle information from the Audi app.”
“I have a 2021 audi a4 that is also being affected by the instrument cluster failure/recall. My model , a4 was not included but I am experiencing the same failure and this was reported to the dealership. An online search will show just how many people have issues with the instr...”
“The main instrument cluster is not stable- it tries to start up then crashes. As a result, speedometer, rpm’s, gas tank gauge, etc are not available while driving. The screen displays blank with a red triangle, tries to start up then crashes again. This seems similar to Audi r...”
Transmission Hesitation, Hard Shifting & Slipping Reports
- Hard gear shifts / delayed engagement into Drive/Reverse
- Transmission shudder / jerking under acceleration
- Transmission slipping between gears
“Tires are original equipment. Only 19,000 miles on them. Was told all 4 tires have belt shifts and hop some. Suggested they should be replaced. These tires were great when new but you could tell from driving they were degrading. I'm ... and never had an issue with tires this n...”
“I am writing to report a persistent issue with my 2021 Audi A4, VIN ... . I have been experiencing a noticeable vibration, humming, and shuddering sensation that occurs specifically when turning at slow speeds (e.g., in a parking lot or when making a tight turn at an intersect...”
“The vehicle at 13,xxx miles on the high ways, and during stop & go traffic; vehicle begins to tremble, transmission and floor shakes, rpms are higher than normal, abnormal noises coming from engine (screeching), jerking on acceleration on the first gears, rough idle, happens o...”
Electric Power Steering Assist & Suspension Noise Reports
- Sudden loss of electric power steering assist
- Steering wheel pull or highway wander
- Clunking / knocking noise over bumps
“I am writing to report a persistent issue with my 2021 Audi A4, VIN ... . I have been experiencing a noticeable vibration, humming, and shuddering sensation that occurs specifically when turning at slow speeds (e.g., in a parking lot or when making a tight turn at an intersect...”
“The contact leased a 2021 Audi A4. The contact stated that the dealer had provided her with the vehicle rental while her vehicle was being repaired. The contact stated that while driving at 4 MPH and turning into a parking pace on the 4th floor of a parking garage, the vehicle...”
“The contact owns a 2021 Audi A4. The contact received notification of NHTSA campaign number: 21V295000 (Suspension) however, the part to do the recall repair was unavailable. The vehicle was taken to the local dealer who stated that the parts were not yet available. The contac...”
Service Brakes, ABS Actuator & Master Cylinder Reports
- Spongy or hard brake pedal travel
- ABS / Brake warning light illuminated
- Extended stopping distance / pedal vibration
“The contact leased a 2021 Audi A4. The contact stated that the dealer had provided her with the vehicle rental while her vehicle was being repaired. The contact stated that while driving at 4 MPH and turning into a parking pace on the 4th floor of a parking garage, the vehicle...”
“The contact owned a 2021 Audi A4. The contact stated that while driving at a low rate of speed through a parking lot, the vehicle independently accelerated and the brake pedal locked. The vehicle accelerated up a hill as the contact was unable to depress the brake pedal; he co...”
Airbag Occupant Detection & Inflator Defect Reports
- SRS Airbag warning lamp illuminated
- Passenger occupant classification sensor failure
- Seat belt retractor lockup
“The contact leased a 2021 Audi A4. The contact stated that the dealer had provided her with the vehicle rental while her vehicle was being repaired. The contact stated that while driving at 4 MPH and turning into a parking pace on the 4th floor of a parking garage, the vehicle...”
“The contact owned a 2021 Audi A4. The contact stated that while driving at a low rate of speed through a parking lot, the vehicle independently accelerated and the brake pedal locked. The vehicle accelerated up a hill as the contact was unable to depress the brake pedal; he co...”
Engine Stalling, Oil Consumption & Cooling Defect Reports
- Engine sudden stall / hesitation while driving
- Abnormal oil burning / consumption
- Check Engine Light (MIL) flashing
- Engine overheating / coolant loss
“The vehicle at 13,xxx miles on the high ways, and during stop & go traffic; vehicle begins to tremble, transmission and floor shakes, rpms are higher than normal, abnormal noises coming from engine (screeching), jerking on acceleration on the first gears, rough idle, happens o...”
Official NHTSA Safety Recalls (4)
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."
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.
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.
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."
Pre-Purchase Inspection Checklist for 2021 Audi A4
Before purchasing a used 2021 Audi A4, perform the following targeted inspections based on reported federal defect patterns:
Scan the OBD-II port under the dash for pending freeze-frame codes (e.g. P0300 misfires, P0087 fuel rail pressure, P0420 catalytic efficiency).
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.
Verify that all 4 NHTSA safety recall campaigns have been performed by an authorized dealership using the VIN.
Ensure the instrument cluster, center screen, and auxiliary charging ports operate with stable 12.0V–14.4V alternator voltage.
Defect & Reliability Q&A: 2021 Audi A4
Is the 2021 Audi A4 a reliable used car?
The 2021 Audi A4 earns a 4.5/10 MazicBay Reliability Index based on 11 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 A4?
The leading complaint category is Electrical Parasitic Drain, Infotainment & Harness Reports, with a median failure point around 55,000 miles (IQR: 35,000 – 75,000 mi).
Are there free recall repairs available for the 2021 Audi A4?
Yes, the NHTSA records 4 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.