Fault Condition: FMI 5 indicates that an open circuit has been
detected in the Water in Fuel Valve Circuit.

Possible repairs:

Turn the ignition key OFF first.

1) If code SID 18 is not set, wiggle the harness and connectors to try to set the code. Visually inspect the Water in Fuel Valve harness connector and wires for frayed or loose connections.
2) Remove fuse 2 at the Engine Power Distribution Module and disconnect the Water in Fuel Valve Relay connector. Check for continuity between pin B at fuse 2 in the Engine Power Distribution Module and pin 4 of the Water in Fuel Valve Relay connector. If there is NO continuity, locate and repair the open circuit between Fuse 2 of the Engine Power Distribution Module and pin 4 of the Water in Fuel Valve Relay.
3) Disconnect connector A at the Engine Management System (EMS) Module and the Water in Fuel Valve Relay connector. Check for continuity between connector A pin 3 at the Engine Management System (EMS) Module and pin 5 of the Water in Fuel Valve Relay connector. If there is NO continuity, locate and repair the open circuit between pin 3 of the Engine Management System (EMS) Module and pin 5 of the Water in Fuel Valve Relay.
4) Disconnect the Water in Fuel Valve Relay connector. Check resistance of the of the primary circuit, between pin 4 and pin 5. If continuity exists, replace the Engine Management System (EMS) Module. If continuity does not exist, replace the Fuel Filter Heater Assembly.