Check Engine Light

The ECM is equipped with Diagnostic Trouble Code (DTC) memory. Malfunctions are stored as constantly present or intermittent (occurred during a trip). DTC memory is erased when battery is disconnected. Malfunctions which are no longer present are erased as follows: after 3 trips CHECK ENGINE light goes out and after an additional 40 warm-up periods, DTC is automatically erased.

A warm-up period is defined as engine coolant temperature less than 95°F (35°C) at engine start with engine coolant temperature increasing to more than 158°F (70°C). A trip is defined as follows:

• Engine running for more than 20 minutes
• Engine oil temperature more than 19°F (-7°C)
• Engine speed more than 500 RPM
• All emission related logic chain functions were checked during previous trips