Test Group VBM2.8VJGKEK & VBM2.8VJGKFK
WARNING: This page does not describe the selected car, but rather 13 other vehicles, including the 1997 BMW Z3, 1997 BMW 850Ci, 1997 BMW 840Ci, 1997 BMW 750iL, and 1997 BMW 740iL. However, it is still accessible from the selected car via links, so may be relevant.
Secondary Air System Monitoring 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. Any time the oxygen sensor indicates a lean mixture within the maximum time for monitoring, a counter is incremented by "one" up to a predetermined value. This fixed limit corresponds to the minimum amount of secondary air (low-flow-limit-check). For secondary air system monitoring flow chart, see Fig 1.