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
| A462350202258412 | 2023-10-05. Service bulletin. SERVICE BRAKES. This bulletin provides information on brake pulsation diagnostic guidelines. |
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| A4623492067132_2 | 2023-10-05. Service bulletin. SERVICE BRAKES. This bulletin provides information on for when there is corrosion on the friction surface of a steel brake disc. |
| A462348203418124 | 2023-10-05. Service bulletin. SERVICE BRAKES. This bulletin provides information on brake noise analysis and handling. |
| A442303202256323 | 2023-10-05. Service bulletin. STEERING. This bulletin provides information for when a steering wheel shimmy, vibration, and/or oscillation is reported. |
| A4023682047920_8 | 2023-10-05. Service bulletin. STRUCTURE:INTERIOR PANELS:DASHBOARD. This bulletin provides information for when there are noises from the front end dash panel when the vehicle is moving. |
| A3923552059129_4 | 2023-10-05. Service bulletin. POWER TRAIN. This bulletin provides information for when there are noises and/or vibrations in tight turns. |
| A2723602067906_3 | 2023-10-05. Service bulletin. ENGINE AND ENGINE COOLING:ENGINE:ENGINE CONTROL MODULE (ECU/ECM). This bulletin provides information for when DTC P0A7D00 is stored. |
| A2723592069747_4 | 2023-10-05. Service bulletin. EQUIPMENT:ELECTRICAL. This bulletin provides information for document requirements before replacing a 12v battery. |
| A0023732061669_2 | 2023-10-05. Service bulletin. EQUIPMENT:ELECTRICAL; EQUIPMENT:OTHER:OWNERS/SERVICE/OTHER MANUAL. This bulletin provides information on workshop mode with Audi connect vehicles. |
| A0023712070568_1 | 2023-10-05. Service bulletin. ENGINE AND ENGINE COOLING. This bulletin provides information on professional noise analysis with the VAS 611 015 PICO NVH Tool. |
| AVin4PinAug23 | 2023-09-01. Service bulletin. STRUCTURE; ENGINE AND ENGINE COOLING; ELECTRICAL SYSTEM; POWER TRAIN; EQUIPMENT. 3.0L engine sound generator malfunctioning Belt noise from starter generator Check engine lamp - DTC P240200 stored in ECM Check engine lamp is on, DTC (s) P010600, P023600, P023700, P023800 "Check engine lamp on, DTC P042000: Catalyst System,Bank1 Efficiency Below" Check engine lamp, Belt Starter Generator DTC U046900 symptom 26950 Fuel pressure low. DTC P008700 Leak from oil pan Low coolant warning in cluster, coolant level is correct MMI screen exhibits "ghost touches" randomly changing screen Noise from front door trim panel while driving USB Trim detached from center console Valve cover leaking oil |
| A9123262071264_1 | 2023-09-01. Service bulletin. EQUIPMENT:ELECTRICAL:NAVIGATIONAL SYSTEM(GLOBAL POSITIONING SYSTEM); EQUIPMENT. This bulletin provides information for when the customer has concerns about the navigation route guidance. |
| A912325206211510 | 2023-09-01. Service bulletin. ELECTRICAL SYSTEM; EQUIPMENT. This bulletin contains instructions to reinstall the navigation database in the presence of DTC B126CF1 stored in the 005F. |
| A9123222061028_5 | 2023-09-01. Service bulletin. EQUIPMENT; ELECTRICAL SYSTEM. This bulletin provides information for when there are no Audi connect services in the MMI, and the SOS LED does not turn green after PDI. |
| A9123212071185_1 | 2023-09-01. Service bulletin. EQUIPMENT:ELECTRICAL:INFOTAINMENT. This bulletin provides information for various connectivity via bluetooth, AMI, or ASI when using CarPlay with Apple iOS devices. |
| A9123202065817_3 | 2023-09-01. Service bulletin. EQUIPMENT; ELECTRICAL SYSTEM. This bulletin provides information for when the key user pairing process or myAudi login cannot be completed in the vehicle. |
| A9023382071281_1 | 2023-09-01. Service bulletin. ELECTRICAL SYSTEM: INSTRUMENT CLUSTER/PANEL; ELECTRICAL SYSTEM. This bulletin provides information for when the warning "Fault: Limited warning messages" appears in the instrument cluster with DTC B174404. |
| A9023352063913_6 | 2023-09-01. Service bulletin. ELECTRICAL SYSTEM: INSTRUMENT CLUSTER/PANEL; ELECTRICAL SYSTEM. This bulletin provides information for when the driver information system display is blank in the instrument cluster. |
| A8723512064077_2 | 2023-09-01. Service bulletin. VISIBILITY:DEFROSTER/DEFOGGER/HVAC SYSTEM. This TSB describes a method for leak detection for R134A and R1234yf refrigerant platforms only. |
| A7223492064695_3 | 2023-09-01. Service bulletin. STRUCTURE:BODY:DOOR:HANDLE:INTERIOR; STRUCTURE:BODY:DOOR:HANDLE:EXTERIOR. This bulletin provides information for an entry/exit assistance comfort concern. |
| A5523792070966_1 | 2023-09-01. Service bulletin. STRUCTURE:BODY:TRUNK LID. This bulletin provides instructions for disabling and reengaging the gesture controlled rear lid (virtual pedal). |
| A4823532065978_3 | 2023-09-01. Service bulletin. STEERING:STEERING WHEEL /HANDLE BAR:HAND HEATER/COOLER. This bulletin provides information for when the steering wheel heating does not heat up sufficiently. |
| A4423022065160_2 | 2023-09-01. Service bulletin. EQUIPMENT; TIRES:TEMPORARY/EMERGENCY SPARE TIRE. This bulletin provides information for when the collapsible wheel does not fully inflate using the toolkit. |
| A4223532038689_7 | 2023-09-01. Service bulletin. SUSPENSION:REAR; SUSPENSION. This bulletin provides information for when there is a rattle noise from the rear suspension. |
| A4023672047920_7 | 2023-09-01. Service bulletin. ENGINE. This bulletin provides information when there are noises from the front end and dash panel when the vehicle is moving. |
The summaries are NHTSA's. Each bulletin's page links NHTSA's copy of the manufacturer's document.