WenmarOpen by Wenmar Pro

Service bulletins for the 2021 Audi S4

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.

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

By type

By component

By trouble code

Bulletins, newest first
A0020362002047_12020-12-21. Service bulletin. EQUIPMENT:ELECTRICAL. This information bulletin contains instructions for technicans on how to ensure their TAC call goes smoothly.
A9120392061490_12020-12-04. Service bulletin. ENGINE AND ENGINE COOLING:ENGINE:OIL/LUBRICATION. This bulletin covers Audi connect: oil level in the myAudi app is implausible
A9120362061345_12020-12-04. Service bulletin. ELECTRICAL SYSTEM; EQUIPMENT:OTHER:OWNERS/SERVICE/OTHER MANUAL. This informational bulletin contains information regarding connectivity issues.
A4620192061331_12020-12-04. Service bulletin. SERVICE BRAKES, AIR:ANTILOCK:ABS WARNING LIGHT; EQUIPMENT:OTHER:OWNERS/SERVICE/OTHER MANUAL. This bulletin contains instructions for addressing an ABS warning light with DTCs C050200 and/or C050800.
A4620182061403_12020-12-04. Service bulletin. SERVICE BRAKES, AIR:DISC:PADS; EQUIPMENT:OTHER:OWNERS/SERVICE/OTHER MANUAL. This bulletin contains instructions for addressing a brake pad wear indicator light with no DTCs.
A9120272061257_12020-12-04. Service bulletin. ELECTRICAL SYSTEM:SOFTWARE. This bulletin contains instructions regarding Audi connect software failures and how to resolve it.
2010-2021EngOil2020-12-04. Service bulletin. EQUIPMENT. Added Saga Part number for 0W40 oil: SAGA Part: G E55040S0
21A4S4TECHREP2020-11-05. Service bulletin. EQUIPMENT; ELECTRICAL SYSTEM. Driver Assistance Section: ADDED: "Activate rear cross traffic assist (if equipped)"
A9120242026611_72020-11-05. Service bulletin. ELECTRICAL SYSTEM; EQUIPMENT. This bulletin contains a guide for troubleshooting HD radio issues.
A4820912053869_42020-11-05. Service bulletin. STEERING:STEERING WHEEL /HANDLE BAR:HAND HEATER/COOLER. This bulletin contains repair instructions for when DTC B145504 with symptom code 7340800.
A9120202061028_12020-11-05. Service bulletin. ELECTRICAL SYSTEM; EQUIPMENT; EQUIPMENT ADAPTIVE/MOBILITY. This bulletin explains and troubleshoots when Audi connect does not have a green SOS light.
A9020732059891_32020-11-05. Service bulletin. EQUIPMENT; ELECTRICAL SYSTEM. This informational bulletin directs you to read the SSP and not perform any repairs for the concern.
A1720112060750_12020-11-05. Service bulletin. ENGINE AND ENGINE COOLING:ENGINE:OIL/LUBRICATION; EQUIPMENT. This bulletin contains instructions for using the UV additive to find engine oil leaks.
A1520352053278_42020-11-05. Service bulletin. ENGINE; STRUCTURE:BODY. 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.
A0020422045316_52020-11-05. Service bulletin. EQUIPMENT ADAPTIVE/MOBILITY; ENGINE AND ENGINE COOLING:ENGINE. This bulletin contains information for diagnosing the Start/Stop system.
21TIREPRSTBL9302020-10-06. Service bulletin. TIRES. Addition of RS 6 Avant
21TIREPRSTBL9242020-10-06. Service bulletin. TIRES. Addition of A4, S4, A4 allroad, A5, S5, RS 5, A6 allroad, S6, A8 L, A8 L TFSI e, S8 L, e-tron, Q8, SQ8, RS Q8
21AUUSMaint09202020-10-06. Service bulletin. EQUIPMENT:OTHER:OWNERS/SERVICE/OTHER MANUAL. New Document
21AUTIRECHAINS2020-10-06. Service bulletin. TIRES; EQUIPMENT; WHEELS. Added new graphic to reflect where to find MY 21 information
A9120142060675_12020-10-06. Service bulletin. STRUCTURE; ELECTRICAL SYSTEM:ADAS:PARKING ASSIST:WARNING; ELECTRICAL SYSTEM:ADAS:PARKING ASSIST:SENSORS; EQUIPMENT:ELECTRICAL. This bulletin contains instructions for addressing the issue when the parking assist will intermittently alert the customer to an obstruction and the sensors look 'pushed in'.
A9120112037809_72020-10-06. Service bulletin. EQUIPMENT:ELECTRICAL:NAVIGATIONAL SYSTEM(GLOBAL POSITIONING SYSTEM). This informational bulletin contains instructions about updating the navigation map.
A9020682059891_22020-10-06. Service bulletin. ELECTRICAL SYSTEM; ENGINE. This informational bulletin directs you to read the SSP and not perform any repairs for the concern.
21A4S4TECHREP2020-10-06. Service bulletin. EQUIPMENT:OTHER:OWNERS/SERVICE/OTHER MANUAL. Vehicle Preparation Section: ADDED: "FCC ID, and Model" to" Verify Audi phone box customer registration form is present in vehicle and add the serial number, FCC ID, and Model from Elsa (if equipped). See TSB 2051720" Media / Radio / SAT Section: ADDED: "Confirm SiriusXM is on and in an active state (can scroll through channels and hear music)" ADDED Phone Box Form to the end of the document
21A4S4ALRDCSDEL2020-10-06. Service bulletin. EQUIPMENT:OTHER:OWNERS/SERVICE/OTHER MANUAL. Infotainment Section: ADDED: - Tune to SiriusXM and show SiriusXM presets and customize based on customers listening preferences - Show differences of SAT vs IP channels through the On Demand category in SiriusXM with 360L equipped vehicles
A9120052060523_12020-09-21. Service bulletin. ELECTRICAL SYSTEM:SOFTWARE. This bulletin contains general instructions for MIB3 software updates.

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