P0492 Secondary Air Injection System (Bank 2)

LK7777

MEMBER
2003 VOLKSWAGEN PASSAT
2.8L
6 CYL
FWD
AUTOMATIC
156,000 MILES

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.

1 Reply

JACOBANDNICKOLAS

MECHANIC
108,164 POSTS

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?