Water in fuel light and check engine light

[Donny Q]

I'm new to posting and RVing. I have a 99 Fleetwood Discovery with a 275 Cummings. While driving the "Water in fuel" light came on. I stopped and changed both fuel filters and drained some fuel. Now the "check engine" light and "water in fuel" light take turns coming on. Sometimes no light at all will be on for a few minutes and then one or the other will come on for a short time. I have drained the separator and there has been no water in it. Has anyone else had this problem or have any ideas?
Thank you.

[GreaTOne65]

Donny Q, I too have a '99 Discovery, what I would do, is pull the cables off of the engine batteries, over night. I had a problem with check engine light on my Jeep, GC, and that's what I did, it reset the ECM. I don't know for sure if the Cummins, will reset the ECM, but maybe worth a try?

[mickey53usa]

Same topic - Water in fuel light then Check Engine Light -
2009 Winnebago Destination 340HP Cummins ISB
This motorhome has seen more rain in the last 14 days than in the last five years. Driving down the road, in the rain, the water in fuel light will come on. I can clear it with the "control joystick." This will happen 10 to 12 times in a 40 to 50 miles. Occasionally the check engine light will come on, but then will clear. I have trouble believing that it is water in the fuel as I fuel at major truck stops. The problem only occurs while driving in the rain. Seems that I heard of water getting splashed into the air intake and this alert triggering. So far there has not been any diminishing in power/performance.
Suggestions?

[dvmweb]

Do you have a water separator fuel filter with a sensor? If so, check it just to be safe.


2013 FleetWood Expedition 38B

[AFChap]

Before moving my fuel filter w/separator & sensor from high on the side of the block to the rear for easy access, I never had a water in fuel light. Since moving it, the light often comes on when driving in the rain. It even came on once after service when the service place washed the rear of the coach after they finished the service. So, the sensitivity of the sensor depends to some degree on how exposed it is, and how well the connector is put together. Since you say you have drained the separator and found no water, I suspect an erroneous reading. Check the connection and ensure it is tight. Some have attempted to wrap it in plastic to shield it from outside moisture.