2002 2BMXV03.0LER, 2BMXV03.0M5R & 2BMXT03.0E5R
WARNING: This page does not describe the selected car, but rather 18 other vehicles, including the 2002 BMW Z8, 2002 BMW Z3, 2002 BMW X5, 2002 BMW M5, and 2002 BMW M3. However, it is still accessible from the selected car via links, so may be relevant.
General Description - At cold start, secondary air pump and valve are switched on for their normal operating function. Secondary air delivered into exhaust gas is causing a lean mixture indicated by output voltage of oxygen sensor. Anytime oxygen sensor indicates a lean mixture within maximum time for monitoring, a counter is incriminated by one, up to a predetermined value. This fixed limit corresponds to minimum amount of secondary air (low flow limit check). See Fig 1.