Fuel water sensor

[Mellem]

Hi new member here, I have a question.....has anyone unplugged the rear water in fuel sensor on a 4th gen ram 3500 diesel? My truck is as 2017 with a filter with sensor by fuel tank, I want to replace the filter with a fleetguard fs1000 water operator filter but it does not have the spot for factory sensor and curious to know if the factory water in fuel sensor is unplugged if it will cause a cel light or display water in fuel.....

 

[Rampant]

Hi new member here, I have a question.....has anyone unplugged the rear water in fuel sensor on a 4th gen ram 3500 diesel? My truck is as 2017 with a filter with sensor by fuel tank, I want to replace the filter with a fleetguard fs1000 water operator filter but it does not have the spot for factory sensor and curious to know if the factory water in fuel sensor is unplugged if it will cause a cel light or display water in fuel.....

Welcome ... I would venture to say yes, it would trip a CEL since the PCM continually monitors it. It seems like it's a very simple two-wire circuit. Water has less resistance than fuel. More water-less resistance= Water in fuel light comes on. I'd say the only way around it is to check resistance during normal operation and wire a jumper with a resistor matching that resistance. Downside is, you'd never know if your fuel was contaminated with water. Hope this helps.

Here's a description of the sensor and how it works:

Water In Fuel Sensor - Operation (6.7L DSL)

OPERATION

The sensor sends an input to the Powertrain Control Module (PCM) when it senses water in the fuel filter/water separator. As the water level in the filter/separator increases, the resistance across the Water in Fuel (WIF) sensor decreases. This decrease in resistance is sent as a signal to the PCM and compared to a high water standard value. Once the value reaches 30 to 40 kilohms, the PCM will activate the water-in-fuel warning lamp through CCD bus circuits. This all takes place when the ignition key is initially put in the ON position. The PCM continues to monitor the input while the engine is running.

 

[FCA Master]

The irony to this sensor is that pure water does not conduct electricity. Granted, the water that contaminates fuel is anything but pure, I just find the irony funny.

 

[Mellem]

Thank you for your help

 

[Jim Lewis]

Hello, yesterday I was driving my 14 3500 home from work and everything was fine, then the WIF light came on and the truck died immediately. Going through an intersection i lost steering, brakes, everything. Pulled over and tried to start it. It cranked but didn't crank smoothly. I am not an expert, but I would think there would be some warning of a problem before the truck just up and dies. I know the filters are due for a change, but I would assume with a 1/2 tank, the WIF light would have come on long before there was enough water to kill the truck?

Anyone have this happen before?

Thanks