Trip Description

WARNING: This page is about a different car, the 2002 Ford Pickup. However, it is still accessible from the selected car via links, so may be relevant.

A "trip" is defined as a Key-On/Key-Off (KOEO) event in which the PCM detects the following:

Engine coolant should be more than 158°F (70°C).
Engine coolant temperature should change more than 68°F (20°C) after starting engine.
Engine speed should be more than 400 RPM.

When compuvalve detects an emission-related DTC, compuvalve uses trip information to make the decision on whether to illuminate MIL. If an emission-related fault is detected, MIL will illuminate and selector switch (ALT/GAS) indicator will change from a steady to an irregular flashing condition. If a fault exists in system being tested, a DTC will be stored in compuvalve memory. Depending on type of fault detected, some DTCs will command MIL to illuminate immediately. Other faults will cause compuvalve to store DTC in memory but will not illuminate MIL until fault is detected again on a subsequent trip (2nd trip).