Test Group VBM2.8VJGKEK & VBM2.8VJGKFK
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.