DEF Head Problems Are Disabling Diesel Vehicles

BROUGHT TO YOU BY Mortons on the Move

"DEF heads are failing at alarming rates, leaving vehicles disabled because replacement parts are unavailable. If you drive a diesel truck, car, or RV made after 2017, your vehicle probably requires diesel exhaust fluid (DEF). You need to understand the definition of a DEF head and how to avoid being stranded by it."

What Is Diesel Exhaust Fluid?

Diesel exhaust fluid (DEF) cleans up the exhaust from a diesel engine. It consists of 32.5% high purity urea and 67.5% pure deionized water. It’s injected into diesel exhaust before the Selective Catalytic Reduction (SCR systems).

How Does a Def Head Work?

A DEF head is the part that draws DEF out of the tank to send it to the exhaust. The DEF head is inserted into the top of a diesel vehicle's DEF tank.

Just like your fuel level, you need to know the level of DEF in your tank. So, the DEF head includes a level sensor. However, in 2017 the EPA mandated additional sensors to check for the quality of DEF fluid. This was because some owners were adding diluted or incorrect fluids to the tank to save money or just as an accident.

What Are the DEF Sensor Issues?

What Happens If Your Def Head Fails?

When the DEF head on a diesel vehicle fails or finds a problem with the diesel exhaust fluid, you will get a notification via the vehicle’s dashboard. It will vary from vehicle to vehicle but usually, it will be the check engine light, DEF fluid light, or even a message on the dash.

Some are Taking Advantage of the Shortage

Replacing a DEF head is expensive, but with the global shortage some are selling DEF heads for thousands more than normal. This is an unfortunate situation because some are looking to alternative options or removing the systems completely.

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Have you had a DEF issue or know someone who has?