Emissions - MIL ON/DTC's P0491 and P0492 Set
01 MIL on (DTC P0491and P0492), stored at the same time
26 12 15
2026528/7
November 5, 2012.
Supersedes Technical Service Bulletin Group 26 number 12-10 dated March 30, 2012 for reasons listed below.
Affected Vehicles
Condition
^ 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.
Technical Background
Not applicable.
Production Solution
Not applicable.
Service
3
For A6 call Technical Assistance Center (TAC), for Audi Q5 and S4 follow below steps.
1. Delete all DTCs and bring engine to operating temperature.
2. Go into "Basic Setting" in VAS tester (VSD) and select "Secondary Air System Check".
To begin, start the test on the tester and then depress first brake pedal and the gas pedal, and then.
3. Observe MVB:
PRS_SA_DIF (note down value at 3sec of test - phase 1 of test, see Figure 1. Pressure test graph) MASS_SA_REL (at the end of test)
Note:
To restart the test you have to back out of VSD to the main screen and cycle the key.
4. Call Technical Assistance Center (TAC) with the results (2 values).
4
Warranty
Additional Information
All parts and service references provided in this TSB are subject to change and/or removal. Always check with your Parts Department and service
manuals for the latest information.
