Volvo All Engines (2004 Emissions) Fault Code: PID 97 FMI 4 Water in Fuel Filter Sensor

Fault Condition: This fault will become active when the EMS Module detects that the Water In Fuel Filter supply voltage is above or below preset specifications. Actual water in the fuel filter will not produce a fault.

Possible repairs:

Turn the ignition key OFF first.

1) Disconnect EMS Module connector B and the Water In Fuel Filter (WIFF) Sensor connector. Measure for continuity between EMS Module harness connector B pin 8 and pin 3 of the WIFF Sensor harness connector.
If there is NO continuity, repair the open in the harness reference voltage line.
2) Disconnect EMS Module connector B and the Water In Fuel Filter (WIFF) Sensor connector. Measure for continuity between EMS Module harness connector B pin 8 and a good ground. If continuity exists, repair the short to ground in the harness voltage line and retest the system.
3) Disconnect EMS Module connector B and the Water In Fuel Filter (WIFF) Sensor connector. Measure for continuity between EMS Module harness connector B pin 10 and pin 2 of the WIFF Sensor harness connector. If there is NO continuity, repair the open in the harness reference line.
4) Visually inspect EMS Module connectors A and B for dirt, loose or shorted pins or deformed contacts. If a repairable open or short is found, or the terminal feels loose, repair EMS Module harness connector.
5) Connect EMS Module connectors A and B. Connect the WIFF Sensor connector. Turn the ignition key ON. If code PID 97 is still active, replace the Water In Fuel Filter (WIFF) Sensor and retest the system. If code PID 97 is still
active, check the EMS Module and connectors A and B for dirt, loose or shorted pins, or any other repairable damage. If no problems are evident, or are NOT repairable, replace the EMS Module and retest the system.
If code PID 97 is NOT active, the diagnostic procedures have corrected the problem. Check all connectors to ensure proper contact.
6) Disconnect the EMS Module harness connectors A and B. Disconnect the harness connector from the Water In Fuel Filter Sensor. Turn the ignition key ON. Measure the battery voltage between pin 3 of the Water In Fuel Filter Sensor connector and a good ground. If there is approximately battery voltage, locate and repair the short to voltage in the signal line. If 0 volts is measured, replace the EMS Module and retest the system.