Fault description

Diagnosis monitors the entire secondary air system in terms of plausible operation and whether sufficient secondary air is injected into the system.

Cylinder bank 1:

Differential pressure of secondary air valve too high after secondary air pump is switched off (>50 mba, provisional value)

and

lambda too high after secondary air pump is switched off (> 1.05; provisional value)

Possible cause of fault:

Valve, cylinder bank 1, stuck open or leak at valve mounting point.