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Service bulletins for the 2018 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.

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

By type

By component

By trouble code

By topic

Bulletins, newest first
A1921122061918_22021-04-06. Service bulletin. ENGINE AND ENGINE COOLING. This bulletin provides guidance on diagnosing a coolant light concern with normal coolant level in the tank.
A1021212059446_42021-04-06. Service bulletin. ENGINE AND ENGINE COOLING. This bulletin contains repair instructions for when oil is lost in the engine compartment.
A9121702062267_12021-03-04. 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.
A3921402059057_32021-03-04. 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_62021-03-04. Service bulletin. ELECTRICAL SYSTEM. This informational bulletin contains software instructions for vehicles with MIB2 with Navigation plus.
A4721082055646_22021-03-04. 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_22021-03-04. 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 15-20212021-03-04. Service bulletin. EQUIPMENT. This special notice is to inform dealers to return the part numbers listed (State of California only).
AWA 21-012021-03-04. 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_12021-03-04. Service bulletin. ELECTRICAL SYSTEM. This bulletin contains guidance for submitting warranty wiring repairs.
A9421342012749_12021-03-04. Service bulletin. EXTERIOR LIGHTING. This bulletin contains instructions for addressing condensation in the headlights.
A4621222051095_42021-03-04. Service bulletin. EQUIPMENT. This informational bulletin contains instructions on how to download and use the Audi Frequency App.
A1521372053278_62021-03-04. Service bulletin. ENGINE AND ENGINE COOLING. 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.
A9421332061922_12021-03-04. Service bulletin. EQUIPMENT. This informational contains instruction on how to document optical concerns for warranty claims.
A4621242034181182021-03-04. Service bulletin. SERVICE BRAKES. This technical service bulletin provides troubleshooting for brake noise.
A4621232022584102021-03-04. Service bulletin. SERVICE BRAKES. This informational bulletin provides diagnostic information for brake conditions.
A4421802056386_42021-03-04. Service bulletin. STEERING. This bulletin contains instructions for when the vehicle pulls to one side or the steering wheel is crooked.
A7221322062113_12021-03-04. Service bulletin. SEATS. This bulletin contains instructions for when the second row backrests won't fold.
A6621692030471_62021-03-04. Service bulletin. EQUIPMENT. This informational bulletin covers the condition of when license plate mounting bracket threaded inserts are stripped.
A4421792022563_12021-03-04. Service bulletin. WHEELS. This bulletin provides information regarding vibrations or movement that are felt in the wheel.
A1721122060750_22021-03-04. Service bulletin. ENGINE AND ENGINE COOLING. This bulletin contains instructions for using the UV additive to find engine oil leaks.
SM 05-20212021-02-04. Service bulletin. EQUIPMENT. This special notice is to inform dealers to return the parts listed if it meets the criteria provided.
A9121642024323_72021-02-04. Service bulletin. PARKING BRAKE:ELECTRICAL:CONTROL MODULE. This bulletin contains technical information regarding when the parking aid sporadically warns of obstacles that don't exist or it is inoperative/constant warning.
A1921112061918_12021-02-04. Service bulletin. ENGINE AND ENGINE COOLING. This bulletin provides guidance on diagnosing a coolant light concern with normal coolant level in the tank.
A1521362053278_52021-02-04. Service bulletin. ENGINE AND ENGINE COOLING:ENGINE:OIL/LUBRICATION. 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.

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