Bi-Fuel Models (Bi-Fuel/CNG System)

RELATIONSHIP BETWEEN MIL, DTC, AND DETECTABLE ITEMS
- When a fault is detected for the first time, the DTC is stored in the Compuvalve memory.
- When the same fault is detected in two consecutive trips or if the fault is emission related, the MIL will come on.
- The MIL will go OFF when the fault condition no longer exists or the vehicle is driven two times with no fault. The MIL will also go OFF if the vehicle switches automatically to gasoline. The drive is counted only when the recorded driving pattern is met. If another fault occurs while counting, the counter will reset.
- The DTC can be displayed until the vehicle is driven 40 times.

Trip
A Trip is defined as a key-on, key-off event in which the PCM detects the following:
- Engine coolant should exceed 70°C (158°F).
- Engine coolant temperature should change more than 20°C (68°F) after starting the engine.
- Engine speed should go over 400 RPM.

When the Compuvalve detects an emission related DTC it uses the trip information to make its decision on whether to illuminate the MIL light.

If a fault exists in the system being tested, a Diagnostic Trouble Code (DTC) will be stored in the Compuvalve memory. Depending on the type of fault detected, some DTCs will command the Malfunction Indicator Light (MIL) to illuminate immediately. Other faults will cause the Compuvalve to store the DTC in memory but will not illuminate the MIL until the fault is detected again on a subsequent trip (2nd trip).