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Service bulletins for the 2021 Audi A4

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.

1057 on file from NHTSA, as of 2026-10-19.

By type

By component

By trouble code

Only bulletins with component: Equipment and accessories are shown. Show all

Bulletins, newest first
A0021482021205_62021-07-02. Service bulletin. EQUIPMENT:OTHER:OWNERS/SERVICE/OTHER MANUAL; STRUCTURE. This informational bulletin explains how to order replacement VIN plates, Safety Certification Labels, etc.
A9121102062115_52021-07-02. Service bulletin. EQUIPMENT:OTHER:OWNERS/SERVICE/OTHER MANUAL; EQUIPMENT:ELECTRICAL:NAVIGATIONAL SYSTEM(GLOBAL POSITIONING SYSTEM). This bulletin contains instructions for when the nav files are corrupted during an update.
A9121092063702_12021-07-02. Service bulletin. ELECTRICAL SYSTEM; EQUIPMENT; EQUIPMENT ADAPTIVE/MOBILITY. This bulletin states to create a PSS when the MMI display turns blue. Workaround provided.
A0021472031473_32021-07-02. Service bulletin. EXTERIOR LIGHTING:HEADLIGHTS:CONCEALMENT DEVICES; EQUIPMENT:OTHER:OWNERS/SERVICE/OTHER MANUAL; STRUCTURE. This information bulletin states to remove the car wash bristle and advise the customer to go somewhere else to prevent it from occurring again.
A9421392063739_12021-07-02. Service bulletin. EQUIPMENT:OTHER:OWNERS/SERVICE/OTHER MANUAL; EXTERIOR LIGHTING:HEADLIGHTS:DAYTIME RUNNING LIGHTS:BULBS. This information bulletin explains how the daylights turn on and off.
A9121082063290_12021-07-02. Service bulletin. EQUIPMENT:OTHER:OWNERS/SERVICE/OTHER MANUAL; ELECTRICAL SYSTEM. This bulletin contains instructions for troubleshooting FoD malfunctions.
A4821052063527_12021-07-02. Service bulletin. STEERING; EQUIPMENT:OTHER:OWNERS/SERVICE/OTHER MANUAL. This bulletin contains instructions for calibrating the steering angel sender G85.
A4821042063528_12021-07-02. Service bulletin. ENGINE; EQUIPMENT. This bulletin contains instructions for addressing intermediate shaft noises that are heard in the engine compartment.
A4821032063546_12021-07-02. Service bulletin. EQUIPMENT; STEERING. This bulletin states how to check for a dynamic steering actuator problem. Solution is under development.
A4821022061904_32021-07-02. Service bulletin. STEERING; EQUIPMENT:OTHER:OWNERS/SERVICE/OTHER MANUAL; ELECTRICAL SYSTEM. This bulletin contains repair instruction for when DTC C110DF0 is stored and the yellow steering lamp is on.
A4321472051336_42021-07-02. Service bulletin. EQUIPMENT:OTHER:OWNERS/SERVICE/OTHER MANUAL. This bulletin contains repair instructions for DTC B200FF0.
21TechRefGde5262021-06-03. Service bulletin. BACK OVER PREVENTION; TIRES:PRESSURE MONITORING AND REGULATING SYSTEMS; EQUIPMENT:ELECTRICAL:NAVIGATIONAL SYSTEM(GLOBAL POSITIONING SYSTEM). All models except Q3, R8, and TT: Settings Section: Split Verify and set language & measurements checklist items into 2 separate with instructions. Changed instructions for "Set Entertainment Fad in Parking aid", " Set Music volune while parking to Medium", and "Turn off Manual Seed Warning". Media/Radio/Sat Section: Changed instructions for "Verify HD Radio is turned "off". On-Hoist Inspection Section: Changed where to store tire pressures for Set and store tirepressures" to "Home > Vehicle > Settings & Service > Tire pressure monitoring". Audi connect Section: Changed instructions for "Turn on the Wi-Fi hotspot", Check Wi-Fi hotspot visibility", and Enable satellite map view for navigation"
A9121052061933_22021-06-03. Service bulletin. ELECTRICAL SYSTEM: INSTRUMENT CLUSTER/PANEL; EQUIPMENT:ELECTRICAL:NAVIGATIONAL SYSTEM(GLOBAL POSITIONING SYSTEM). This bulletin contains an explanation and troubleshooting for the Navigation messages in the instrument cluster.
A9121042024323_82021-06-03. Service bulletin. EQUIPMENT:OTHER:OWNERS/SERVICE/OTHER MANUAL; ELECTRICAL SYSTEM:ADAS:PARKING ASSIST:SOFTWARE. This bulletin contains technical information regarding when the parking aid sporadically warns of obstacles that don't exist or it is inoperative/constant warning.
SM 39-20212021-06-03. Service bulletin. EQUIPMENT. This special notice is to inform dealers to return the parts listed and only order the successor parts going forward
A9021032058077_52021-06-03. Service bulletin. EQUIPMENT; SERVICE BRAKES. This bulletin contains instructions for determining unexpected Audi presense interventions.
A1021222018288_92021-06-03. Service bulletin. EQUIPMENT; ENGINE AND ENGINE COOLING. This technical service bulletin reminds the reader to check for metal debris when replacing an engine.
A0021442052680_32021-06-03. Service bulletin. EQUIPMENT. This bulletin contains instructions for additional reporting requirements for safety related inquiries (airbag/seatbelts, accidents, fire and overheat damage).
SM 37-20212021-06-03. Service bulletin. EQUIPMENT. This special notice is to inform dealers to return the parts listed if it meets the criteria provided.
A4421822056386_52021-06-03. Service bulletin. EQUIPMENT ADAPTIVE/MOBILITY:VEHICLE CONTROLS:STEERING. This bulletin contains instructions for when the vehicle pulls to one side or the steering wheel is crooked.
21A4S4TECHREP2021-06-02. Service bulletin. EQUIPMENT ADAPTIVE/MOBILITY; EQUIPMENT:OTHER:OWNERS/SERVICE/OTHER MANUAL. Settings Section Split "Verify and Set language & Vehicle Measurements" into two separate checklist items. Post-Road Test Inspection Section: Added "See TSB 2061028" to the end of The vehicle must not be delivered to the customer if the emergency call function has not been successfully activated (LED lights up in green).
A9021002032113_52021-05-06. Service bulletin. EQUIPMENT. This information bulletin contains a background on the outside air temperature reading.
A6421792047061_32021-05-06. Service bulletin. EQUIPMENT:OTHER:LABELS. This bulletin contains a cleaning procedure from leftover residue from suction cups or labels.
A9121882062115_42021-05-06. Service bulletin. EQUIPMENT; EQUIPMENT:ELECTRICAL:NAVIGATIONAL SYSTEM(GLOBAL POSITIONING SYSTEM). This bulletin contains instructions for when the nav files are corrupted during an update.
A5521542062730_12021-05-06. Service bulletin. EQUIPMENT. This bulletin explains why the compartment lid cannot be closed using the buttons on the key sometimes.

The summaries are NHTSA's. Each bulletin's page links NHTSA's copy of the manufacturer's document.