Cummins ISB4.5 CM2150 Fault Code: 1852 PID: SPN: 97 FMI: 16 Water-in-Fuel Indicator – Data Valid But Above Normal Operating Range – Moderately Severe Level.

Circuit Description
The water-in-fuel sensor is attached to the fuel filter. The water-in-fuel sensor sends a signal to the engine control module (ECM) when a set volume of water has accumulated in the fuel filter. The water-in-fuel circuit contains two wires, a ground wire and a signal wire.

Component Location
The water-in-fuel sensor is integrated into the bottom of the fuel filter. The filter housing location will vary with each original equipment manufacturer (OEM).

Conditions for Running the Diagnostics
This diagnostic runs continuously when the engine is running.

Conditions for Setting the Fault Codes
Water has been detected in the fuel filter housing above the warning limit.

Action Taken When the Fault Code is Active
The ECM illuminates the amber CHECK ENGINE light and/or the malfunction indicator lamp (MIL) immediately when the diagnostic runs and fails.

Conditions for Clearing the Fault Code
-To validate the repair, start the engine and let it idle for 1 minute.
-The ECM will turn off the amber CHECK ENGINE light immediately after the diagnostic runs and passes.
-The ECM will turn off the MIL after three consecutive ignition cycles that the diagnostic runs and passes.
-This fault code and MIL can also be cleared with INSITE™ electronic service tool.

Shop Talk
Water in the fuel can do extensive damage to the fuel system due to the tight tolerances of fuel system components.

It must be drained immediately.

If this fault code is active and there is no water in the fuel filter, a malfunctioning Water-In-Fuel sensor is a likely cause.

Reference the appropriate OEM wiring diagram when troubleshooting circuits that utilize wiring supplied by the OEM.