OBD-II Drive Cycle & Malfunction Indicator Lamp Function

When a malfunction is present for two consecutive drive cycles, the MIL is turned on, except for steady state catalyst efficiency monitor and misfire detection monitor. The MIL is turned on for a steady state catalyst efficiency monitor malfunction after the malfunction is present for three consecutive drive cycles. When a misfire that would cause catalyst damage is detected, the MIL will turn on or flash. If the misfire is the type that will cause an emission failure or an inspection maintenance failure, the MIL Will turn on after the malfunction is detected during the next drive cycle. The MIL is turned off after three consecutive drive cycles without the same malfunction being detected provided no other DTCs are stored that would independently turn the MIL on. The actual number of drive cycles necessary to control the MIL varies with each monitor. See appropriate monitor under ON BOARD DIAGNOSTIC II MONITORS .