WIF light on at startup but there ain't no WIF...

barley00 · **Posted:** Tue Nov 10, 2015 6:56 pm

pretty sure my WIF sensor is malfunctioning. Recently changed fuel filter and the WIF light started to come on after the change (It was not showing up beforehand). Drained and reinstalled fuel filter and the WIF light still comes on at a cold startup and stays on for a minute or two...I'm 99.9% sure there ain't no WIF. Anyone know how to check the sensor?

olypopper · **Posted:** Tue Nov 10, 2015 7:13 pm

They are a simple, circuit completion type wif sensor. Use an ohmmeter to check continuity between pins. There shouldn't be any unless there is water completing the circuit or a shorted wif sensor. A meter will tell you. Also, there can be shorted harness problems too but start with the easy stuff like checking the filter head.

Yeti · **Posted:** Wed Nov 11, 2015 10:56 am

it's shorted

barley00 · **Posted:** Sat Nov 14, 2015 3:46 pm

Damned if I can find where...there's no resistance across pins on the plug or the sensor, wires look good into harness...

Yeti · **Posted:** Sat Nov 14, 2015 4:06 pm

if you read zero on the sensor in OHM position , there is no physic resistance or unlimited.........shorted , some multimeter make a beep if you short the pin and you read zero

barley00 · **Posted:** Sat Nov 14, 2015 4:15 pm

Sorry, perhaps I used the wrong description, in this case I am using resistance and continuity to mean the same thing...there is no continuity across the pins so that tells me the pins are ok and there's a short somewhere else, correct?

papaindigo · **Posted:** Sat Nov 14, 2015 5:05 pm

IIRC the WIF sensor is a simply 2 wire/pin item. If there is no water in the fuel no current passes between the pins but if there is water in the fuel then current passes between the pins thru the water sending a signal to the body control module which turns on the WIF light.

If so test the WIF sensor as follows:
1. check for continuity between the plug (should have 2 poles) on the bottom of the WIF and the pin associated with each pole (i.e. looking to see if current can pass thru WIF from outside to inside) - if continuity plug and pin(s) are ok - if no continuity then WIF has a broken internal connection and needs to be replaced.
2. check for continuity between the 2 poles on the bottom of the WIF - if no continuity WIF is ok (i.e. circuit is "broken" because there is no water between the sensor pins) - if there is continuity WIF has an internal short between the 2 sensor pins and needs to be replaced.

I have no clue how to test signal to BCM or even for power to WIF.

Yeti · **Posted:** Sat Nov 14, 2015 5:07 pm

if there is no resistance and you read zero the sensor is ok , but I think you have do a bad fuel , strange that the light go off after some minute , if there a persistent water or a short the light stay on and do not go away

olypopper · **Posted:** Sun Nov 15, 2015 1:56 am

I've seen this on outboard motors and it was the PCM. If you find a schematic and physically unplug the wire from the connector for the WIF and the light still comes on, you have a problem in the computer. If the problem goes away, your issue lies in the wiring harness.

WIF light on at startup but there ain't no WIF...

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