2021 Audi S8 Service and Repair Manual

This 2021 Audi S8 factory service and repair manual is built around this exact model year and trim, so the specifications, wiring diagrams and repair sequences inside are the ones Audi published for your car, not a generic approximation pulled from a related year.

Under the hood is the 4.0L V8 (CWWB) Turbocharged Mild Hybrid EV-Gas (MHEV), and the factory procedures for it are covered in full.

Engines covered

• 4.0L V8 mild hybrid (244 cu in) — DOHC, turbocharged, gasoline

Body styles covered

• 4-door sedan

Trims covered

• Base

Known issues on the 2021 S8. Eight recalls are on federal record for this model year. Several involve the rear-view camera and backup display: software errors can prevent the camera image from appearing or leave the screen blank when the vehicle is placed in reverse, cutting off the driver's rear visibility. Rear seat belt automatic locking retractors may deactivate early, preventing a child restraint system from securing properly. Rear axle alignment tied to an earlier trailing-arm lock nut repair may have gone uninspected, and a separate lock nut can break from stress corrosion and misalign the rear axle. A missing sealing pin in the engine control module connector may let moisture in and cause the ECM to malfunction, risking a stall. A software error can also cause the instrument panel display to fail, cutting off speedometer and warning-light visibility. Owners have filed 1 complaint for the year. The factory diagnostic and repair procedures behind each of those systems are here.

From a rearview camera fault to an engine control module or rear axle inspection, it keeps you on the OEM procedure and the correct specification for your specific 2021 S8.