This is pretty common on here.

It's usually moisture making its way into the sensor which is triggering it, so you're going to have to tape up the connection really good and see if it works.

Or at least someway to prevent any moisture getting in, it'll be a trial and error process

If that doesn't work then put a little piece of tape on your dash covering the wif light

 

See i dried the sensor out real well and cleaned it. Then dielectric grease. Still have the issue

 

I too am suffering from WIF alert... I have also changed my filters and drained off several times to find just fuel in there... but will keep trying. I have not seen much about the front WIF sensor but that one looks like a pain to reach so maybe one of the last spots?

Please share if you solve the issue, I will as well.

 

I am going to do some measurement on my old one to see what resistance value it has, maybe even do some dips in fuel and then watered fuel to see what it reads out to... will keep you posted.

 

So, no testing done yet but I did have one enlightening moment after putting my new AlfaOBD reader on the case...it tells me that the WIF circuit is reading HI and that leads me to believe that the input is expected to return back at a slightly lower R level as the probe will have some continuity thru the fuel and allow the ECU to see the expected R value. Also assuming if water was present, the probe is positioned in a spot that would have water collected there first and would read "open" or HI value as the water is not as good a conductor as Diesel and has higher resistance?
Any electronics experts please feel free to add anything here, I am grasping at straws here but, unplugging the sensor circuit altogether gives the same HI reading as I am getting with the sensor "connected"
As I said, further testing will need to be done and a decent connection made to verify anything.

 

I think I would do a continuity check on the harness. If that checked out I’d do it on the sensor using a jumper between the contacts.