Early Fuel Evaporation ( EFE ): Testing and Inspection

Chart C-9B - Electrically Heated EFE Check - ECM Controlled:

Wiring Diagram for Chart C-9B - Electrically Heated EFE Check - ECM Controlled:

CHART C-9B - ELECTRICALLY HEATED EFE CHECK - ECM CONTROLLED


Circuit Description:

The electrically heated EFE is a wire grid heater mounted between the carburetor and intake manifold. It is operated by an ECM controlled relay. The relay is supplied 12V by ignition, and the ECM completes the ground to energize the relay and turn the EFE Grid "ON" when:

^ Engine is below a given temperature

^ Engine below a given load


Test Description:

1. Checks to see if there is current flow to the heater. Grounding the test terminal should cause the ECM to turn the relay "ON" and energize the heater circuit. Test light should normally be on.


2. Substitutes ground normally provided by ECM. This separates the fault into an ECM/ECM wiring problem or Relay/relay wiring related problem. Test light would normally be "ON" if relay and relay wiring are OK.