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Audi · Known Issues

2020 Audi A6 Problems: 6 Known Issues

2020 model year · NHTSA recalls, manufacturer TSBs, and owner forum reports · Updated September 2026

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Issue summary

According to Au7o's research across NHTSA recalls, manufacturer TSBs, and owner forum reports, the 2020 Audi A6 has 6 documented known issues, with 2 rated critical. The most serious are 48V Belt Starter-Generator Warning and VIN-Specific Campaigns and Gateway Control Module Liquid-Ingress Recall 90V2 (22V-861) ($0-$0 repair). Across all issues with published estimates, repair costs range from $100 to $2,500. DIY maintenance guides at au7o.io.

In This Article

  • A6 Electrical3
  • A6 Engine2
  • A6 Suspension1
  • Recalls14
  • FAQ
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In This Article

  • Electrical3
  • Engine2
  • Suspension1
  • Recalls14
  • FAQ

All 6 Known Issues

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ALL YEARS2025202420232022202120202019201820172016201520142013201220112010200920082007200620052004200320022001200019991998199719961995

On the 2019-2025 Audi A6, a 48V electrical-system warning on a mild-hybrid A6 is not repaired with an ordinary 12V battery, charger, alternator, or starter. Certain 2019-2020 2.0T mild-hybrid vehicles are covered by safety recall 27H2 or 20V-153 for moisture intrusion into the belt starter generator, which can cause a short circuit, smoldering, or fire. Audi also issued VIN-specific service action 27BQ for qualifying later vehicles. Outside those campaigns, the exact Audi fault code and symptom number matter: U046900 with symptom 34763 and actual mode 8 can point to another CAN or sensor fault, and Audi states that replacing the starter generator will not fix that case.

Common Symptoms

  • 48V electrical-system warning
  • Electrical-system malfunction message
  • Burning odor, smoke, or smoldering from the engine compartment on recall-affected vehicles

How to Fix

Check the VIN with Audi for open 27H2, 20V-153, or 27BQ work before authorizing parts. Follow Audi's safety instructions for an open fire-risk campaign and have the dealer perform the remedy. For a warning outside an open campaign, use Audi ODIS-guided diagnosis and preserve the complete code, symptom number, and actual mode. U046900 or P0CA700 alone is not permission to order a starter generator. Audi must select the correct starter-alternator suffix and associated hardware by VIN and guided-test result. Do not buy any of the former Optima, ACDelco, Battery Tender, Denso, or Remy 12V products for this 48V fault.

Find a Audi dealer

Choose to share your location for this search, or enter an area below. Your search location is sent to Google to find dealers.

Open Audi dealer map in Google Maps ↗

Call to confirm they service Audi vehicles and check your VIN, recall eligibility, parts availability, and appointment options.

What you need to fix it

Only diagnosis- and fitment-reviewed repair parts are linked here.

Check your VIN for an open recall before buying.A dealer repairs an open manufacturer recall at no charge. Confirm coverage with NHTSA first.
  • 48V belt starter generator and campaign hardware (VIN-specific dealer selection)

    Quantity 1 only when an open campaign or Audi guided diagnosis requires replacement. The part suffix and hardware are VIN-specific; no consumer commerce link is safe.

Owner tips & cautions

  • TipSave a scan showing the full Audi symptom number and actual mode. U046900 by itself is not enough to select a starter generator.
  • WarningA conventional 12V battery, trickle charger, starter, or alternator cannot substitute for the 48V campaign remedy or guided diagnosis.

Research This Issue

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NHTSA Verified
High ConfidenceVerifiedReviewed Jul 2026

On the 2019-2022 Audi A6, certain 2019-2022 Audi A6 Sedan and 2020-2022 A6 allroad vehicles are included in safety recall 22V-861, Audi campaign 90V2. Liquid spilled on the rear seat can reach the gateway control module beneath the rear middle seat. If the module detects implausible signals or internal short circuits, its safety strategy can shut down gateway communication. Multiple warnings can appear and engine power can be reduced unexpectedly. Audi states that the engine remains running in emergency mode and that steering and braking remain available; the earlier claim that this recall causes complete engine shutdown was inaccurate.

This issue also affects: Audi Q5 Sportback, Audi S7

Common Symptoms

  • Multiple warning messages appear after liquid is spilled on the rear seat
  • Engine power is reduced and the vehicle enters emergency mode
  • Gateway communication faults affect several vehicle systems

How to Fix

Check the VIN in Audi's official recall lookup and have an authorized Audi dealer complete campaign 90V2 if it is open. The recall remedy is installation of a protective cover over the gateway control module at no charge. Do not buy a scanner, repair manual, or replacement gateway module as the recall fix. If warning messages or sudden reduced power occur, move out of traffic safely and arrange prompt dealer diagnosis; a module already affected by liquid requires vehicle-specific diagnosis and campaign or warranty handling.

Find a Audi dealer

Choose to share your location for this search, or enter an area below. Your search location is sent to Google to find dealers.

Open Audi dealer map in Google Maps ↗

Call to confirm they service Audi vehicles and check your VIN, recall eligibility, parts availability, and appointment options.

What you need to fix it

Only diagnosis- and fitment-reviewed repair parts are linked here.

Check your VIN for an open recall before buying.A dealer repairs an open manufacturer recall at no charge. Confirm coverage with NHTSA first.
  • Gateway control module protective-cover recall remedy
    $0

    An authorized Audi dealer verifies campaign 90V2 by VIN and installs the protective cover free of charge.

Owner tips & cautions

  • TipEnter the VIN in Audi's campaign lookup; model and year alone cannot confirm whether 90V2 is open on a particular A6.
  • WarningMultiple warnings and sudden reduced engine power require prompt dealer diagnosis. A generic OBD scanner or replacement module is not the recall remedy.
Typical repair cost:$0 - $0

Research This Issue

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NHTSA Verified
High ConfidenceVerifiedReviewed Jul 2026

On the 2005-2023 Audi A6, the Audi A6 is prone to various electrical gremlins across all generations, including window regulator failures, door lock actuator failures, MMI/infotainment glitches, and battery drain issues. Window regulators fail due to weak plastic clips in the mechanism, causing windows to drop into the door or move slowly. Door lock actuators wear out, causing doors to unlock randomly, fail to lock, or make grinding noises. MMI (Multi Media Interface) infotainment systems freeze, reboot randomly, or display "SAFE" mode. Battery drain issues (parasitic draw) are common, leaving the car dead after sitting for a few days. Many electrical issues are caused by aging control modules, corroded connectors, or software bugs. While frustrating, most electrical issues are not safety-critical and can be addressed individually as they arise.

Common Symptoms

  • Window drops into door or won't roll up/down
  • Door locks fail to lock or unlock (one or more doors)
  • Grinding or clicking noise from door when locking
  • MMI screen freezes, reboots, or shows "SAFE" mode
  • Battery dies after car sits for 2-3 days
  • Warning lights for systems that work fine (phantom codes)
  • Backup camera, parking sensors, or adaptive cruise intermittent

How to Fix

Window regulator replacement: $300-$600 per window (DIY $150-$250 with aftermarket kit). Order regulator with metal clips, not plastic. Door lock actuator: $200-$400 per door at dealer, DIY $50-$100 per actuator (1-hour job). MMI/infotainment glitches: Perform hard reset (hold power + volume up for 10 seconds). If that fails, Audi dealer can update software or replace MMI unit ($1,000-$2,500). Battery drain: Have dealer perform parasitic draw test to identify faulty module. Common culprits: trunk electronics, MMI, comfort control module. Address issues as they arise—most are minor annoyances, not showstoppers.

What you need to fix it

Only diagnosis- and fitment-reviewed repair parts are linked here.

  • Genuine Audi front-left window regulator, motor not included
    OEM4F0837461DCross-ref4F0837461C (previous revision)

    Quantity 1 only for a mechanically confirmed front-left regulator failure on the C6 A6. Confirm VIN and door position before ordering.

    eBayFCP Euro

As an Amazon Associate, we earn from qualifying purchases; other part links may also earn au7o a commission. Confirm fitment by VIN before buying.

Owner tips & cautions

  • TipListen for the motor and watch whether the glass tilts before buying anything. Motor noise with poor glass movement points toward the mechanical regulator; silence requires an electrical diagnosis first.
  • Warning4F0837461D is front-left and does not include the motor. It is not the right part for another door position or for a failed switch, motor, door module, or lost one-touch setting.
  • WarningThe front door contains a side-airbag sensor. Follow the factory battery and airbag safety procedure before disassembling the window frame.
Typical repair cost:$100 - $2,500

Research This Issue

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Community Reported
Medium Confidence

On the 2005-2023 Audi A6, water pump failures are common across all A6 generations due to plastic impeller degradation and seal leaks. Audi uses plastic impellers that crack or disintegrate over time (typically 80,000-120,000 miles), causing coolant leaks and overheating. The water pump is often driven by the timing belt or timing chain, so replacement is recommended during timing service to save labor. Thermostat housings also crack due to heat cycling, causing coolant leaks and erratic temperature readings. Symptoms include coolant leaks under the car, overheating in traffic, temperature gauge fluctuations, and coolant warning lights. Ignoring a failed water pump can lead to severe engine overheating, warped cylinder heads, and blown head gaskets ($3,000-$5,000 repair). Some models have electric auxiliary water pumps that also fail, causing poor heater performance.

This issue also affects: Audi Q7, Audi A4, Audi A5 Sportback

Common Symptoms

  • Coolant leak under front of car (pink/green puddle)
  • Overheating in stop-and-go traffic or at idle
  • Temperature gauge rising above normal (middle position)
  • Coolant warning light or low coolant message
  • No heat from cabin heater (auxiliary pump failure)
  • Hissing or gurgling noise from engine bay
  • Steam or coolant smell from engine

How to Fix

Replace water pump AND thermostat together ($800-$1,500 with labor). Always use OEM or high-quality aftermarket parts (Rein, Hepu)—cheap pumps fail within 20,000 miles. If water pump is timing belt/chain driven, replace during timing service to save labor. Flush cooling system and refill with OEM Audi G12++ or G13 coolant (do NOT mix types). Inspect coolant hoses and replace if cracked. If auxiliary electric water pump fails, replace separately ($300-$600). Monitor coolant level weekly and address leaks immediately to prevent overheating damage.

What you need to fix it

Only diagnosis- and fitment-reviewed repair parts are linked here.

  • Beck/Arnley 131-2517 main engine water pump
    Cross-refBeck/Arnley 131-2517

    Confirm VIN and current fitment before ordering; this is not an auxiliary water pump.

    eBay

As an Amazon Associate, we earn from qualifying purchases; other part links may also earn au7o a commission. Confirm fitment by VIN before buying.

Owner tips & cautions

  • TipPhotograph the suspected leak before cleaning it, then recheck after the system is filled and the car is driven. The Audi bulletin requires the leak to be reproduced rather than inferred from old residue.
  • WarningConfirm that the failed component is the main engine coolant pump. The A6 also has auxiliary pumps, and those are different parts with different repair roles.
Typical repair cost:$800 - $1,500

Research This Issue

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Community Reported
Medium Confidence

On the 2019-2021 Audi A6 3.0L TFSI, for a 2019-2021 Audi A6 equipped with the 3.0L TFSI engine, the malfunction indicator lamp may illuminate with P0300 and one or more cylinder-specific P0301-P0306 codes. Audi's service information identifies an applicable ECM software-calibration condition and publishes model-year-specific software levels. Misfire codes alone do not prove intake-valve carbon buildup, and the previous card incorrectly grouped 2011-2023 A6 models, multiple unrelated engine generations, a fixed walnut-blasting interval, fuel additives, universal catch cans, and generic shopping searches into one diagnosis. This corrected record covers only the Audi-documented software condition; carbon cleaning or parts replacement requires separate physical diagnosis if the misfire remains after the software level and other common causes are checked.

This issue also affects: Audi S8, Audi A4, Audi A1

Common Symptoms

  • Malfunction indicator lamp or check-engine light illuminated
  • P0300 random/multiple-cylinder misfire stored
  • One or more P0301-P0306 cylinder-specific misfire codes stored

How to Fix

Record every stored DTC and freeze-frame before clearing faults. Confirm that the vehicle is a 2019-2021 A6 with the 3.0L engine, then have an Audi dealer or qualified VAG specialist compare the ECM J623 part number and software version with Audi's bulletin and perform the specified Software Version Management update when applicable. For MY2019 the bulletin lists 4K0907559A version 0007 updating to 0008 with SVM action 01A255; MY2020 lists 4K0907559D version 0002 updating to 0003; MY2021 lists 4K0907559K versions 0001-0002 updating to 0004. Recheck for misfires after the update. If faults persist, diagnose ignition, plugs, injectors, fuel quality, air leaks, compression, and only then inspect the intake valves before authorizing cleaning. Do not buy a catch can, cleaner, ignition part, or walnut-blasting service solely from P0300-P0306.

Owner tips & cautions

  • TipSave the complete scan and freeze-frame before an update or repair. The cylinder pattern and operating conditions are useful if the misfire remains.
  • WarningP0300-P0306 do not identify carbon buildup by themselves. Verify the Audi software level and diagnose the remaining possible causes before paying for walnut blasting or ordering parts.
  • WarningThe published fix is software, so ShowMeTheParts cannot validate it and no retail product link belongs on this record.

Research This Issue

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Manually Verified
High ConfidenceVerifiedReviewed Jul 2026

On the 2018-2021 Audi A6, audi TSB 2062932/1 describes an informational diagnostic issue on 2018-2021 A6/A7 vehicles with adaptive suspension. During PDI or diagnosis, ODIS address 0074 may show accumulator or system pressure above 25 bar even though that is not the actual pressure; some J775 suspension-control-module versions report the measuring value incorrectly. The previous card instead claimed that 2012-2018 Premium Plus and Prestige A6 sedans commonly burn out compressors at a fixed mileage, assigned 1,400 owner reports without source evidence, and recommended Arnott P-3250, relay 8K0951253, and compressor 4G0616005C without proving the vehicle had adaptive air suspension or that any of those parts matched.

Common Symptoms

  • ODIS address 0074 displays accumulator or system pressure above 25 bar
  • The finding may occur during PDI or diagnosis with no customer complaint
  • Displayed pressure does not agree with a physical system-pressure measurement

How to Fix

First confirm by VIN/PR equipment that the vehicle has adaptive suspension. If ODIS address 0074 shows accumulator or system pressure above 25 bar, do not condemn the compressor from that value. Audi specifies using air-suspension leak-detection tester VAS 751 001 to measure actual pressure and evaluate compressor output. A real sag, leak, run-time, or ride-height complaint still requires the separate factory leak, valve-block, air-spring, relay, wiring, temperature-protection, and compressor diagnostics for that VIN. Replace a compressor only after measured output and the rest of the air-supply system identify it as failed. This bulletin itself specifies a diagnostic tool rather than a replacement part, so the old product links are removed.

Owner tips & cautions

  • WarningDo not replace the compressor, relay, or air springs solely because ODIS displays more than 25 bar. Audi says that displayed value may be incorrect.
  • TipAsk the shop to document the VIN/PR equipment and the physical VAS 751 001 pressure result, not only the address-0074 screen value.

Research This Issue

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Manually Verified
High ConfidenceVerifiedReviewed Jul 2026
NHTSA Recalls14 recalls

SEAT BELTS:REAR/OTHER:RETRACTOR

Volkswagen Group of America, Inc. (Audi) is recalling certain 2025 SQ6 E-Tron, SQ6 Sportback E-Tron, Q6 Sportback E-Tron, A6, A5, A6 Sportback E-Tron, Q6 E-Tron, S5, and S6 Sportback E-Tron vehicles. The automatic locking retractor may fail to engage when a child seat is installed using the seat belt. As such, these vehicles fail to comply with the requirements of Federal Motor Vehicle Safety Standard (FMVSS) numbers 208, "Occupant Crash Protection" and 209, "Seat Belt Assemblies."

Campaign #25V89900019/12/2025

BACK OVER PREVENTION: SENSING SYSTEM: CAMERA

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."

Campaign #25V90000019/12/2025

ENGINE AND ENGINE COOLING:ENGINE:ENGINE CONTROL MODULE (ECU/ECM)

Volkswagen Group of America, Inc. (Audi) is recalling certain 2022 Audi A6 Sedan, A4 Sedan, Q5, and Q5 Sportback vehicles. The semiconductor inside the engine control unit may short-circuit and cause an engine stall.

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Frequently Asked Questions

What are the most common Audi A6 problems?

According to Au7o's research across NHTSA recalls, manufacturer TSBs, and owner forum reports, the 2020 Audi A6 has 6 documented issues. The most frequently reported are: 48V Belt Starter-Generator Warning and VIN-Specific Campaigns, Gateway Control Module Liquid-Ingress Recall 90V2 (22V-861), Water Pump and Thermostat Failure (Overheating). Of these, 2 are rated critical and should be addressed promptly.

Is the Audi A6 reliable?

The 2020 Audi A6 has 6 known issues compiled from NHTSA recalls, manufacturer TSBs, and owner forum reports. 2 issues are rated critical: 48V Belt Starter-Generator Warning and VIN-Specific Campaigns and Gateway Control Module Liquid-Ingress Recall 90V2 (22V-861). Prospective buyers should inspect for these issues and factor potential repair costs into their purchase decision. Regular maintenance following the manufacturer's schedule helps prevent many common problems.

How much does it cost to fix common Audi A6 problems?

Repair costs for known Audi A6 issues range from $0 to $2,500, depending on the specific problem and whether you choose DIY or professional repair. Au7o provides step-by-step DIY maintenance guides that can help reduce repair costs.

What is the 2019-2025 Audi A6 48V Belt Starter-Generator Warning and VIN-Specific Campaigns?

A 48V electrical-system warning on a mild-hybrid A6 is not repaired with an ordinary 12V battery, charger, alternator, or starter. Certain 2019-2020 2.0T mild-hybrid vehicles are covered by safety recall 27H2 or 20V-153 for moisture intrusion into the belt starter generator, whic… Severity: high.

What is the 2019-2022 Audi A6 Gateway Control Module Liquid-Ingress Recall 90V2 (22V-861)?

Certain 2019-2022 Audi A6 Sedan and 2020-2022 A6 allroad vehicles are included in safety recall 22V-861, Audi campaign 90V2. Liquid spilled on the rear seat can reach the gateway control module beneath the rear middle seat. If the module detects implausible signals or internal sh… Repairs typically run $0-$0. Severity: high.

Content on this page was compiled with AI assistance using NHTSA complaints, TSBs, owner reports, and public automotive data. While we strive for accuracy, this information may contain errors. Always verify repair procedures and specifications with your vehicle's service manual or a qualified mechanic.

Data compiled from NHTSA recalls, manufacturer TSBs, automotive forums, and AI-assisted research. No aggregated owner-report counts available for this vehicle yet.

Campaign #22V36800023/05/2022

EQUIPMENT:ELECTRICAL:INFOTAINMENT:VIDEO (TOUCH)SCREEN/MONITOR/UNIT

Volkswagen Group of America, Inc. (Audi) is recalling certain 2021-2022 AUDI A8, A6 Allroad, E-TRON Quattro, 2022 S3, RSQ8, RS7, RS6 Avant, Q8, Q7, Q3, E-TRON Sportback Quattro, S5 Cabriolet, E-TRON GT, S5 Sportback, A7, A6, A5 Sportback, A5 Cabriolet, A4, A4 Allroad, A3, S8, SQ7, SQ8, S6, and S4 vehicles. The infotainment main unit may become damaged internally when the vehicle is shut off, resulting in an inoperative rearview camera display the next time the vehicle is started. As such, these vehicles fail to comply with the requirements of Federal Motor Vehicle Safety Standard number 111, "Rear Visibility."

Campaign #22V80600026/10/2022

ELECTRICAL SYSTEM

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.

Campaign #22V86100021/11/2022

+ 9 more recalls. Check all on NHTSA.gov

Enter your VIN at NHTSA.gov to check recalls specific to your vehicle.

What is the 2005-2023 Audi A6 Water Pump and Thermostat Failure (Overheating)?

Water pump failures are common across all A6 generations due to plastic impeller degradation and seal leaks. Audi uses plastic impellers that crack or disintegrate over time (typically 80,000-120,000 miles), causing coolant leaks and overheating. The water pump is often driven by… Repairs typically run $800-$1,500. Severity: medium.

What is the 2019-2021 Audi A6 2019-2021 A6 3.0L Misfire Codes - Check ECM Software Before Mechanical Cleaning?

For a 2019-2021 Audi A6 equipped with the 3.0L TFSI engine, the malfunction indicator lamp may illuminate with P0300 and one or more cylinder-specific P0301-P0306 codes. Audi's service information identifies an applicable ECM software-calibration condition and publishes model-yea… Severity: medium.

What is the 2005-2023 Audi A6 Electrical Issues (Window Regulators, Door Locks, MMI)?

The Audi A6 is prone to various electrical gremlins across all generations, including window regulator failures, door lock actuator failures, MMI/infotainment glitches, and battery drain issues. Window regulators fail due to weak plastic clips in the mechanism, causing windows to… Repairs typically run $100-$2,500. Severity: low.

What is the 2018-2021 Audi A6 2018-2021 A6 Adaptive Suspension - Verify Compressor Pressure With a Physical Tester?

Audi TSB 2062932/1 describes an informational diagnostic issue on 2018-2021 A6/A7 vehicles with adaptive suspension. During PDI or diagnosis, ODIS address 0074 may show accumulator or system pressure above 25 bar even though that is not the actual pressure; some J775 suspension-c… Severity: low.