Trip Definition
A "Trip" means vehicle operation (following an engine-off period) of duration and driving mode such that all components and systems are monitored at least once by diagnostic system. The monitors must successfully pass before PCM can verify that a previously malfunctioning component is meeting normal operating conditions of that component. For misfire or fuel system malfunction, MIL may be extinguished if fault does not recur when monitored during three subsequent sequential driving cycles in which conditions are similar to those under which malfunction was first determined.
Anytime MIL is illuminated, a DTC is stored. The DTC can self erase only after MIL has been extinguished. Once MIL is extinguished, PCM must pass diagnostic test for most recent DTC for 40 warm-up cycles (80 warm-up cycles for Fuel System Monitor and Misfire Monitor). A warm-up cycle can best be described by the following:
- The engine must be running.
- A rise of 40°F in engine temperature must occur from time when engine was started.
- Engine coolant temperature must crossover 160°F.
- A "driving cycle" that consists of engine start up and engine shut off.
Once above conditions occur, PCM is considered to have passed a warm-up cycle. Due to conditions required to extinguish MIL and erase DTC, it is most important that after a repair has been made, all DTC's be erased and repair verified by running 1 good trip.