Service bulletins for the 2021 Audi A4 allroad
A bulletin is a manufacturer's communication to its dealers, as NHTSA indexes it. The summary is NHTSA's. The document is the manufacturer's: read it at NHTSA. A bulletin is not a recall, and listing a model year does not mean every vehicle of it is concerned.
785 on file from NHTSA, as of 2026-10-19.
By type
By component
By trouble code
Only bulletins with component: Heating and air conditioning are shown. Show all
| A8724702064077_4 | 2024-04-04. Service bulletin. VISIBILITY:DEFROSTER/DEFOGGER/HVAC SYSTEM:REFRIGERANT HOSES AND FITTINGS. This TSB describes a method for leak detection for R134A and R1234yf refrigerant platforms only. |
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| A8723602064077_3 | 2023-11-06. Service bulletin. VISIBILITY:DEFROSTER/DEFOGGER/HVAC SYSTEM:REFRIGERANT HOSES AND FITTINGS. This TSB describes a method for leak detection for R134A and R1234yf refrigerant platforms only. |
| A8723512064077_2 | 2023-09-01. Service bulletin. VISIBILITY:DEFROSTER/DEFOGGER/HVAC SYSTEM. This TSB describes a method for leak detection for R134A and R1234yf refrigerant platforms only. |
| A8723452041717_9 | 2023-08-04. Service bulletin. VISIBILITY:DEFROSTER/DEFOGGER/HVAC SYSTEM. This bulletin provides information on the GFF test plan required when replacing the A/C compressor. |
| A5723022058452_4 | 2023-04-06. Service bulletin. VISIBILITY:DEFROSTER/DEFOGGER/HVAC SYSTEM. This bulletin provides information for when the rear window defogger is not operational. |
| A9123742069112_2 | 2023-03-06. Service bulletin. VISIBILITY:DEFROSTER/DEFOGGER/HVAC SYSTEM; EQUIPMENT:ELECTRICAL. This bulletin provides information on a software update for when saved addresses, favorites, last destinations, HVAC favorite button assignment, and/or icon and shortcut order are lost sporadically; In rare cases the screen may turn completely blue until a bus sleep or an MMI reboot is performed. For Q3 vehicles, MMI may get stuck on the welcome screen. No DTCs are stored. |
| A9123732069112_1 | 2023-03-06. Service bulletin. VISIBILITY:DEFROSTER/DEFOGGER/HVAC SYSTEM; EQUIPMENT:ELECTRICAL. This bulletin provides information on a software update for when saved addresses, favorites, last destinations, HVAC favorite button assignment, and/or icon and shortcut order are lost sporadically; In rare cases the screen may turn completely blue until a bus sleep or an MMI reboot is performed. For Q3 vehicles, MMI may get stuck on the welcome screen. No DTCs are stored. |
| A8023122062583_2 | 2023-02-07. Service bulletin. VISIBILITY:DEFROSTER/DEFOGGER/HVAC SYSTEM. This bulletin provides instructions for when the customer advises that there is insufficient or uneven cabin heating from the HVAC system. |
| A8722272041717_8 | 2022-06-07. Service bulletin. VISIBILITY:DEFROSTER/DEFOGGER/HVAC SYSTEM. This informational bulletin details on how to get a GFF test plan for A/C compressor replacements. |
| A872225201014617 | 2022-05-05. Service bulletin. VISIBILITY:DEFROSTER/DEFOGGER/HVAC SYSTEM. This bulletin contains instructions for properly cleaning and removing a musty odor from the heating and ventilation system. |
The summaries are NHTSA's. Each bulletin's page links NHTSA's copy of the manufacturer's document.