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
| A6421802020552_1 | 2021-06-03. Service bulletin. VISIBILITY:GLASS, SIDE/REAR. This bulletin provides instructions on how to clean exterior glass. |
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| A4821002061904_2 | 2021-06-03. Service bulletin. STEERING:STEERING CONTROL MODULE. This bulletin contains repair instruction for when DTC C110DF0 is stored and the yellow steering lamp is on. |
| A4421822056386_5 | 2021-06-03. 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. |
| 21A4S4TECHREP | 2021-06-02. 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). |
| ELSAallignAudi | 2021-05-06. Service bulletin. ELECTRICAL SYSTEM. Elsa2Go campaign information is now 100% aligned with ElsaPro. This update to Elsa2Go ensures that both systems are displaying the same campaign information, including OPEN/CLOSED status, repair date as well as criterions at the same time without any discrepancy. |
| A9021982059335_2 | 2021-05-06. Service bulletin. ELECTRICAL SYSTEM: INSTRUMENT CLUSTER/PANEL; ELECTRICAL SYSTEM. This bulletin contains information on noises from the instrument cluster installation area. |
| A9021002032113_5 | 2021-05-06. Service bulletin. EQUIPMENT. This information bulletin contains a background on the outside air temperature reading. |
| A9021992063038_1 | 2021-05-06. Service bulletin. ELECTRICAL SYSTEM: INSTRUMENT CLUSTER/PANEL; ELECTRICAL SYSTEM. This informational bulletin explains why the version information pops-up. |
| A4321462051336_3 | 2021-05-06. Service bulletin. SUSPENSION; ELECTRICAL SYSTEM. This bulletin contains repair instructions for DTC B200FF0. |
| A6421792047061_3 | 2021-05-06. Service bulletin. EQUIPMENT:OTHER:LABELS. This bulletin contains a cleaning procedure from leftover residue from suction cups or labels. |
| A0121042062862_1 | 2021-05-06. Service bulletin. ELECTRICAL SYSTEM. This bulletin states that if DTC P227900, P001600, and DTC P001700 recorded together in the ECM to follow the isntructions on replacing the intake manifold pressure sender. |
| A9121882062115_4 | 2021-05-06. Service bulletin. EQUIPMENT; EQUIPMENT:ELECTRICAL:NAVIGATIONAL SYSTEM(GLOBAL POSITIONING SYSTEM). This bulletin contains instructions for when the nav files are corrupted during an update. |
| A5721752022032_9 | 2021-05-06. Service bulletin. LATCHES/LOCKS/LINKAGES; ELECTRICAL SYSTEM. This technical service bulletin provides troubleshooting information for the vehicle locking system. |
| A5521542062730_1 | 2021-05-06. Service bulletin. EQUIPMENT. This bulletin explains why the compartment lid cannot be closed using the buttons on the key sometimes. |
| A1521382053278_7 | 2021-05-06. Service bulletin. ENGINE. This bulletin contains repair instructions for 3.0 and 2.9 TFSI engines that have oil loss around the engine compartment, front end, and underbody. |
| A9121862062713_1 | 2021-04-06. Service bulletin. EQUIPMENT. This bulletin contains repair instructions for when there is radio static when the rear heater is active. |
| A5521532062669_1 | 2021-04-06. Service bulletin. ENGINE AND ENGINE COOLING. This bulletin states that this is a normal condition and to not perform any repairs. |
| SSP_970893 | 2021-04-06. Service bulletin. ELECTRICAL SYSTEM. eSelf-Study Program 970893 - Third-generation modular infotainment matrix. |
| A9421362023322_3 | 2021-04-06. Service bulletin. EXTERIOR LIGHTING. This informational bulletin contains information on the different shading of LED headlights. |
| A8021112062583_1 | 2021-04-06. Service bulletin. EQUIPMENT. This bulletin contains instructions for addressing an insufficient or uneven heating performance from the HVAC system. |
| A5021062062633_1 | 2021-04-06. Service bulletin. STRUCTURE. This bulletin contains instructions for when there is a creaking noise in the floor area while strongly braking or steering where the vehicle's body is twisted. |
| A9121822062115_3 | 2021-04-06. Service bulletin. ELECTRICAL SYSTEM. This bulletin contains instructions for when the nav files are corrupted during an update. |
| A9121802062466_1 | 2021-04-06. Service bulletin. ELECTRICAL SYSTEM. This informational bulletin contains instructions about Apple Carplay cannot be started with Wi-Fi. |
| A4821962055733_2 | 2021-04-06. Service bulletin. STEERING. This bulletin contains repair instructions for repositioning the intermediate steering shaft when there is squeaking noises from the steering column. |
| A1321132062387_1 | 2021-04-06. Service bulletin. ENGINE AND ENGINE COOLING. This bulletin contains instructions for determining if a repair is needed when coolant touches a poly V-belt and/or a toothed belt. |
The summaries are NHTSA's. Each bulletin's page links NHTSA's copy of the manufacturer's document.