Two-Trip Detection Logic

Two-trip detection logic is used to prevent erroneous malfunction detection. When a malfunction initially occurs, Diagnostic Trouble Code (DTC) is temporarily stored in ECM memory, but MIL on instrument panel will not illuminate.

The second time that a malfunction is detected, MIL on instrument panel will illuminate, provided ignition is turned off and then back on after first malfunction was detected. This is referred to as 2-Trip Detection Logic and only applies to specific DTCs.