Service bulletins for the 2010 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.
912 on file from NHTSA, as of 2026-10-19.
About P0491 on the 2010 Audi A4: what the code means, and the bulletins and recalls about the same components.
By type
By component
By trouble code
Only bulletins with trouble code: P0491 are shown. Show all
| 26 12 15 2026528 | 2022-05-31. Service bulletin. ELECTRICAL SYSTEM; VISIBILITY:DEFROSTER/DEFOGGER/HVAC SYSTEM:AIR HANDLER/CHAMBER, DUCTS, AND VALVES. MIL on. DTC P0491 and P0492 (Secondary Air System Insufficient Flow, Bank 1/2) are stored at the same time. |
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| 26 12 15 2026528 | 2022-05-02. Service bulletin. ELECTRICAL SYSTEM. DTC P0491 and P0492 (Secondary Air System Insufficient Flow, Bank 1/2) are stored at the same time. |
| A011383 2033001- | 2017-11-17. Service bulletin. ENGINE AND ENGINE COOLING; ENGINE AND ENGINE COOLING:COOLING SYSTEM. MIL on. DTC P0491 and P0492 (Secondary Air System Insufficient Flow, Bank 1/2) are stored at the same time. Mileage is greater than 15,000 miles. Under certain driving conditions, the secondary air ports in the cylinder head can accumulate carbon over time, causing a restriction. |
| A261215 2026528- | 2017-11-08. Service bulletin. ELECTRICAL SYSTEM. Supersedes Technical Service Bulletin Group 26 number 12-10 dated March 30, 2012. MIL on. DTC P0491 and P0492 (Secondary Air System Insufficient Flow, Bank 1/2) are stored at the same time. Mileage greater than 20,000 miles. |
The summaries are NHTSA's. Each bulletin's page links NHTSA's copy of the manufacturer's document.