CM871 and CM876 Electronic Control Systems, ISX and ISM Engines – FAULT CODE 418

Water-In-Fuel Indicator – Data Valid but Above Normal Operational Range – Least Severe Level


Fault Code: 418
PID: P097
SPN: 97
FMI: 0/15
LAMP: Maintenance

Water-In-Fuel Indicator – Data Valid but Above Normal Operational Range – Least Severe Level. Water has been detected in the fuel filter.

Possible white smoke, loss of power, or hard starting.

ISX – Water-In-Fuel Indicator
ISM – Water-In-Fuel Indicator

Circuit Description

The water-in-fuel sensor is attached to the fuel filter. The electronic control module (ECM) provides a 5 VDC reference signal to the water-in-fuel sensor. When the water collected in the fuel filter covers the sensor probes, the water-in-fuel sensor then pulls the 5 VDC reference voltage to ground indicating high water accumulation in the fuel filter.

Component Location

The water-in-fuel sensor is integrated into the bottom of the OEM supplied suction fuel filter.

Conditions for Running the Diagnostics

This diagnostic runs continuously when the keyswitch is in the ON position.

Conditions for Setting the Fault Codes

The ECM detects that water in the fuel filter is above the sensor level.

Action Taken When the Fault Code is Active

  • The ECM illuminates the flashing amber MAINTENANCE light immediately when the diagnostic runs and fails.

Conditions for Clearing the Fault Code

The ECM will turn off the flashing amber MAINTENANCE light immediately after the water has been drained from the fuel filter.

Shop Talk

Verify the electronic control module (ECM) calibration is correct. Check the calibration revision history found on QuickServe® Online for applicable fixes to the calibration stored in the ECM. If necessary, recalibrate the ECM. Refer to Procedure 019-032 (ECM Calibration Code) in Section 19 in the corresponding Troubleshooting and Repair Manual for the engine being serviced.

This fault code indicates that water has been detected in the water separation fuel filter. Drain the water from the fuel filter.

Refer to Troubleshooting Fault Code t05-418

Last Modified:  09-Jul-2010