Audi · Known Issues

Audi S4 Problems & Known Issues

2000-2009, 2011-2015, 2018-2020 model years · NHTSA recalls, manufacturer TSBs, and owner forum reports · Updated July 2026

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According to Au7o's research across NHTSA recalls, manufacturer TSBs, and owner forum reports, the 2000-2009, 2011-2015, 2018-2020 Audi S4 has 6 documented known issues, with 5 rated critical. The most serious are Airbag-Control Software May Miss Front-Airbag Deployment After a Second Impact (Recall 14V667 / 69K5), Fuel Rail or Seal Leak Creates Fire Risk (Recall 15V019 / 24AP), Driver Airbag Inflator May Deploy Improperly (Recall 21V470 / 69CJ), Xenon Headlamp Reflector Coating Can Reduce Light Output (Recall 05V096) and Passenger Airbag Inflator Can Rupture (Recall 18V427 / 69R7). DIY maintenance guides at au7o.io.

Frequently Asked Questions

What are the most common Audi S4 problems?

According to Au7o's research across NHTSA recalls, manufacturer TSBs, and owner forum reports, the 2000-2009, 2011-2015, 2018-2020 Audi S4 has 6 documented issues. The most frequently reported are: Airbag-Control Software May Miss Front-Airbag Deployment After a Second Impact (Recall 14V667 / 69K5), Fuel Rail or Seal Leak Creates Fire Risk (Recall 15V019 / 24AP), Driver Airbag Inflator May Deploy Improperly (Recall 21V470 / 69CJ). Of these, 5 are rated critical and should be addressed promptly.

Is the Audi S4 reliable?

The 2000-2009, 2011-2015, 2018-2020 Audi S4 has 6 known issues compiled from NHTSA recalls, manufacturer TSBs, and owner forum reports. 5 issues are rated critical: Airbag-Control Software May Miss Front-Airbag Deployment After a Second Impact (Recall 14V667 / 69K5) and Fuel Rail or Seal Leak Creates Fire Risk (Recall 15V019 / 24AP) and Driver Airbag Inflator May Deploy Improperly (Recall 21V470 / 69CJ) and Xenon Headlamp Reflector Coating Can Reduce Light Output (Recall 05V096) and Passenger Airbag Inflator Can Rupture (Recall 18V427 / 69R7). 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.

What year Audi S4 is the most reliable?

Reliability varies across model years of the Audi S4. Based on documented issues, problems are most commonly reported in earlier model years. Au7o recommends checking the specific known issues for your target year before purchasing, and having a pre-purchase inspection performed by a qualified mechanic. Our known issues database covers the 2000-2009, 2011-2015, 2018-2020 Audi S4 with 6 documented issues compiled from NHTSA recalls, manufacturer TSBs, and owner forum reports.

What is the 2013-2015 Audi S4 Airbag-Control Software May Miss Front-Airbag Deployment After a Second Impact (Recall 14V667 / 69K5)?

On certain 2013-2015 S4 vehicles, an airbag-control algorithm may fail to command the front airbags after a side-airbag deployment followed by a second frontal impact. Severity: high.

What is the 2011-2012 Audi S4 Fuel Rail or Seal Leak Creates Fire Risk (Recall 15V019 / 24AP)?

Certain 2011-2012 S4 fuel-injection systems can leak at the fuel rails or corresponding seals, creating a fire risk near an ignition source. Severity: high.

What is the 2000-2002 Audi S4 Driver Airbag Inflator May Deploy Improperly (Recall 21V470 / 69CJ)?

Certain 2000-2002 S4 vehicles have a non-azide driver airbag inflator that can absorb moisture and deploy improperly, reducing occupant protection in a crash. Severity: high.

What is the 2003-2004 Audi S4 Xenon Headlamp Reflector Coating Can Reduce Light Output (Recall 05V096)?

Certain 2003-2004 S4 xenon headlamp reflectors can lose coating over time, reducing luminous transmittance and the driver’s field of view. Severity: high.

What is the 2005-2009 Audi S4 Passenger Airbag Inflator Can Rupture (Recall 18V427 / 69R7)?

Certain 2005-2009 S4 body styles contain passenger frontal-airbag inflators that can rupture after long-term humidity and temperature exposure, propelling metal fragments into the cabin. Severity: high.

What is the 2018-2020 Audi S4 Thermostat Does Not Close Completely With Cooling-System DTCs (TSB 2058767/7)?

Audi TSB 2058767/7 covers bounded 2018-2020 S4 3.0 TFSI VIN ranges with the MIL on, a fan that may run continuously, and at least two cooling-system or coolant-temperature DTCs caused by a thermostat that does not close completely. Severity: medium.

Audi S4 Problems & Known Issues

All 6 Known Issues

2013-2015 Audi S4: Airbag-Control Software May Miss Front-Airbag Deployment After a Second Impact (Recall 14V667 / 69K5)#

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2000-2002 Audi S4: Driver Airbag Inflator May Deploy Improperly (Recall 21V470 / 69CJ)#

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2005-2009 Audi S4: Passenger Airbag Inflator Can Rupture (Recall 18V427 / 69R7)#

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2011-2012 Audi S4: Fuel Rail or Seal Leak Creates Fire Risk (Recall 15V019 / 24AP)#

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2003-2004 Audi S4: Xenon Headlamp Reflector Coating Can Reduce Light Output (Recall 05V096)#

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2018-2020 Audi S4: Thermostat Does Not Close Completely With Cooling-System DTCs (TSB 2058767/7)#

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Other Audi Models

Frequently Asked Questions

What are the most common Audi S4 problems?

Is the Audi S4 reliable?

What year Audi S4 is the most reliable?

What is the 2013-2015 Audi S4 Airbag-Control Software May Miss Front-Airbag Deployment After a Second Impact (Recall 14V667 / 69K5)?

What is the 2011-2012 Audi S4 Fuel Rail or Seal Leak Creates Fire Risk (Recall 15V019 / 24AP)?

What is the 2000-2002 Audi S4 Driver Airbag Inflator May Deploy Improperly (Recall 21V470 / 69CJ)?

What is the 2003-2004 Audi S4 Xenon Headlamp Reflector Coating Can Reduce Light Output (Recall 05V096)?

What is the 2005-2009 Audi S4 Passenger Airbag Inflator Can Rupture (Recall 18V427 / 69R7)?

What is the 2018-2020 Audi S4 Thermostat Does Not Close Completely With Cooling-System DTCs (TSB 2058767/7)?