P0492 Secondary Air Injection System (Bank 2)

2003 VOLKSWAGEN PASSAT
156,000 MILES • 2.8L • 6 CYL • FWD • AUTOMATIC
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LK7777
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Can you explain me how the Motronic Engine Control Module throws P0492 code? I didn't find any sensor that could give the ECM any input information on conditions of the secondary air injection system. Does it compute some indirect data like the output of the O2 Sensors?

As far as I understand, if I get constantly P0492 but never P0491 codes, the AIR (secondary air) Pump and AIR solenoid valve N112 operate properly, and the reason of the problem is somewhere in the the Bank 2 AIR branch: Combi-Valve. But I might be wrong with my assumptions.
Aug 18, 2014 at 12:08 PM
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JACOBANDNICKOLAS
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Have you checked the combination valve? Have you checked for leaking or plugged vacuum lines? Have you checked the fuel pump relay? Have you checked secondary air pump for power / fuse issue / relay?
Aug 18, 2014 at 7:06 PM