Service bulletins for the 2019 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.
859 on file from NHTSA, as of 2026-10-19.
By type
By component
By trouble code
| 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. |
| A9121812056076_1 | 2021-04-06. Service bulletin. ELECTRICAL SYSTEM. This bulletin contains instructions for when there is no diagnostics communication with the ConBox. |
| 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. |
| SM 17-2021 | 2021-04-06. Service bulletin. ELECTRICAL SYSTEM. This special notice is to inform dealers to return the parts listed if it meets the criteria provided. |
| A9121792062480_1 | 2021-04-06. Service bulletin. ELECTRICAL SYSTEM. This bulletin states to clear the DTCs and release the vehicle. |
| A9121782050565_3 | 2021-04-06. Service bulletin. ELECTRICAL SYSTEM. This bulletin contains general software update instructions for vehicles with PR Code 7UH. |
| A9121772056076_1 | 2021-04-06. Service bulletin. ELECTRICAL SYSTEM. This bulletin contains instructions for when there is no diagnostics communication with the ConBox. |
| A9121762037809_8 | 2021-04-06. Service bulletin. EQUIPMENT. This informational bulletin contains instructions about updating the navigation map. |
| A3921422051558_6 | 2021-04-06. Service bulletin. ELECTRICAL SYSTEM: INSTRUMENT CLUSTER/PANEL. This bulletin contains repair instructions for when the message "four-wheel drive malfunction" shows up sporadically in the instrument cluster with DTC C05ED00. |
| A1921122061918_2 | 2021-04-06. Service bulletin. ENGINE AND ENGINE COOLING. This bulletin provides guidance on diagnosing a coolant light concern with normal coolant level in the tank. |
| A1021212059446_4 | 2021-04-06. Service bulletin. ENGINE AND ENGINE COOLING. This bulletin contains repair instructions for when oil is lost in the engine compartment. |
| A9121702062267_1 | 2021-03-04. Service bulletin. EQUIPMENT:OTHER:OWNERS/SERVICE/OTHER MANUAL. This bulletin states to not perform any repairs and show the customer how to manually re-enable the map. |
| A5721742058452_2 | 2021-03-04. Service bulletin. VISIBILITY. This bulletin contains repair instructions for when the rear window defog button will light up and then turn off. |
| A3921402059057_3 | 2021-03-04. Service bulletin. WHEELS; SUSPENSION. This bulletin contains repair instructions for noises when in reverse or vibrations/humming/droning or rubbing when fully turning the wheel. |
| A9121722047576_6 | 2021-03-04. Service bulletin. ELECTRICAL SYSTEM. This informational bulletin contains software instructions for vehicles with MIB2 with Navigation plus. |
| A4721082055646_2 | 2021-03-04. Service bulletin. SERVICE BRAKES. This bulletin contains repair instructions for when the vehicle sporadically does not start and there is a hard brake pedal concern. |
| A4621252054385_2 | 2021-03-04. Service bulletin. EQUIPMENT; SERVICE BRAKES. This informational contains an explanation for when the customer hears creaking noises when braking at almost standstill (crawling when pulling away or briefly before standstill). |
| SM 15-2021 | 2021-03-04. Service bulletin. EQUIPMENT. This special notice is to inform dealers to return the part numbers listed (State of California only). |
| AWA 21-01 | 2021-03-04. Service bulletin. EQUIPMENT:APPLIANCE:AIR CONDITIONER. This Document informs dealers on the new A/C evaporator warranty extension for 2017-2021 A4/S4/Q7 and 2018-2021 A5/S5/Q5 vehicles |
| A9721782061976_1 | 2021-03-04. Service bulletin. ELECTRICAL SYSTEM. This bulletin contains guidance for submitting warranty wiring repairs. |
| A9421342012749_1 | 2021-03-04. Service bulletin. EXTERIOR LIGHTING. This bulletin contains instructions for addressing condensation in the headlights. |
| A4621222051095_4 | 2021-03-04. Service bulletin. EQUIPMENT. This informational bulletin contains instructions on how to download and use the Audi Frequency App. |
The summaries are NHTSA's. Each bulletin's page links NHTSA's copy of the manufacturer's document.