The water in fuel sensor is mounted in engines equipped with a Duramax water pump. These pumps are present in vehicles with diesel and turbocharged engines to produce efficient power. In addition, they measure the extra water in the fuel assembly and show the warning message or indicator light on the cluster screen.
Duramax water in fuel sensor problems include a warning message on the screen, incorrect installation of the sensor, corroded connectors, broken wires, loose screws, incorrect water detection, bent float of sensors, and brittle or damaged sensors.
It measures the presence of water in the fuel filters via the difference in water conductivity from the diesel or fuel. Water can enter the fuel system because of the contaminated fuel and leakages of the water delivery system. Water entry in engine components is not good because it causes difficulty starting your vehicle and rough idling.
| Problems | Solutions |
| Water in fuel message on the screen | Replace module |
| Incorrect installation of the sensor | Install sensor according to manufacturer’s guidelines |
| Corroded connectors and sensors | Clean the sensor with vinegar |
| Broken wires of sensors | Check the broken cable of the sensor |
| Loose screws | Ensure screws tightening |
| Incorrect water detection | Change the damaged sensor |
| Bent float of sensors | Replace sensor |
| Brittle or damaged sensors | Select an aluminum sensor instead of a plastic |
| Contaminated fuel | Avoid new and flooded fuel stations |
Water in fuel message on the screen
Water in the fuel sensor is mounted beneath the fuel filter with two screws. In addition, it has two wires connected to its counterparts to supply power for its functioning.
It transmits the signals to the electronic control module of your truck. My friend has the high-country 2500 crew cab, which he owned in 2018 with 150k miles driven.
He did not face any issue with their parts, but suddenly, a “water in fuel” warning light came on the screen. He said he flushed the fuel system and drained the water but this message remained on the screen.
I suggested replacing the fuel filters or flushing the fuel tank completely, and he did the same, but the issue was not resolved. The light disappeared from the screen temporarily and then again came back.
He became worried and contacted the dealership to fix the problem. The dealerships told him the problem was in the WiF sensor, which caused the illumination of the warning light.
The sensor was not working correctly and determining the presence of water. It showed the light even when water was not in the fuel system.
The dealerships replaced the send unit and module located on the front tires. He went for the test drive, and the warning light did not illuminate again.
Incorrect installation of the sensor
Many people install WiF sensors in their vehicles as an aftermarket accessory for ease and to enhance the durability of diesel engines. It triggers the water in fuel warning light on the screen when the water level in the fuel delivery system becomes high to prevent the engine parts from water-related damages, including misfiring and poor idling.
Sometimes, this device cannot detect the presence of water because of incorrect installation. You have to install them correctly for their efficient functioning.
It cannot measure the conductivity of the water because of its incorrect installation. The issue comes from incorrectly positioning the probes that measure water, fuel, and diesel conductance.
The issue also comes when it is not properly submerged in the fuel system because of its incorrect installation. It is better to install it correctly according to the manufacturer’s guidelines.
Follow the guidelines that are mentioned in the manual given to these devices.
Corroded connectors and sensors
Sensors are comprised of several components, including wires, probes, connectors, and screws. These connectors and probes measure the conductivity of water and diesel and trigger the warning sign when water concentration rises in the fuel delivery system of your vehicle.
Sometimes, the electric connectors can corrode and cannot measure conductivity.
In addition, contaminants present in fuel also increase the risk of corrosion on their connectors or probes. Mix the vinegar or baking soda in water to clean the corroded contacts. Spray the solution on the probe and wipe it off with a clean cloth.
Broken wires of sensors
You can see two wires connected to the sensors for its functioning. These wires send the input and receive the outputs to supply power for its working.
Water in fuel message can appear because of the broken wires. The wires can break because of their incorrect installation. These are delicate and can also break during fuel filter replacement and cleaning.
In addition, the issue can also come because of their age and power surges. Power surges cause overheating and melting of the insulation layer of wires. Check the current wires supply and replace the broken cables with new ones.
Loose screws
It is mounted beneath the fuel filters with two screws. These screws are responsible to secure its accurate position and ensure the normal functioning.
Sometimes these screws become loose and cause misalignment of this device. It cannot detect the presence of water because of its incorrect alignment. It is necessary to tighten the screws after installing the sensor.
Incorrect water detection
Damaged sensors cannot detect the presence of water in the engine system. You cannot use the emulsifying agents to remove the water from the fuel system because of the presence of alcohol.
Most of these fuel additives have alcohol and acetone that absorb the water, which are strictly prohibited for the diesel injection system.
You can see the incorrect reading and water in fuel alert on the screen because of the failure of the sensors. Replacing the broken or damaged part with a new one is necessary for correct detection.
Bent float of sensors
It has a float that moves up and down to measure the water presence in the fuel delivery and engine system. This device is the reed switch, and it automatically shuts off when the float moves up because of the water’s presence.
The float settles at the bottom when only fuel is present there. Sometimes, the float can bend because of the frequent up-and-down movement and changes in the concentration of water and fuel.
It can also bend because it is manufactured with delicate material. You cannot repair the bent float, so you have to replace this part with a new one.
Brittle or damaged sensors
WIF sensors are made of plastic material that is vulnerable to chipping and cracking with age. In addition, it can also become brittle because of the exposure to high engine temperature.
Plastic material can easily come when it comes under high-temperature conditions. These can crack easily because of the brittle manufacturing material.
In addition, these can break during fuel filter replacement. Removal and installation of new fuel filters increase their risk of damage because of the delicate construction material.
You should replace the fuel filters carefully or hire a mechanic for it. Moreover, I purchased aluminum-made water fuel sensors instead of plastic ones because these are durable and less vulnerable to brittleness.
Contaminated fuel
Contaminated fuel affects the standard performance of the WIF sensors over time.
Long-term water exposure increases the risk of malfunctioning of these devices. The issue comes when selecting the refilling stations near the Hurricanes and moist or humid areas.
The underground fuel storage tanks in these areas are highly contaminated with water because of the weather conditions, and as a result, you can see water in the fuel message on the dashboard. You should not fill your vehicle’s fuel tanks from stations that are flooded with water.
Moreover, new fuel tanks are at more risk of water contamination and junk presence. I also avoid fuel filling at the new stations because of the increased chances of the presence of contaminants and junk.
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