Ford F-250 Diesel: Electrical Sensors Guide

Here is a detailed breakdown of some of the important electrical sensors in your Ford F-250 or F-350 Super Duty.

By Pizzaman711 - November 21, 2014

This article applies to the Ford F-250, F-350 Super Duty Diesel (2005-2014).

Your F-250 or F-350 Super Duty Diesel truck is full of different electrical sensors monitoring everything in your truck, from fastening your seat belt to the amount of oxygen going in your exhaust. Like anything else in your truck, sensors are capable of failing. The Ford truck's sensors are expected to last for the life of the truck, however, things could go wrong and you might need to replace some. This article will cover the sensors specific to the emissions from your diesel motor. It's always best to know what these sensors do to be able to diagnose where a problem is coming from if it arises.

Component Breakdown

Diesel Exhaust Fluid Level Sensor

The Diesel Exhaust Fluid (DEF) Sensor measures the amount of DEF you have. DEF is in all the newer trucks to help counteract the environmental impact of a diesel motor. When the exhaust is leaving the truck it's combined with DEF to greatly cut down on the amount of NOX released. Issues with these aren't that common, however it's still a relatively new technology for the trucks so it's bound to have some problems. Issues you might see will be DEF level readings that aren't accurate and bounce around, or your truck won't tell you when you're low on DEF at all. If the sensor registers that you're out of DEF, it'll put the truck in limp mode thus limiting your speed, so it's best to get it replaced as soon as a problem arises.

Diesel Exhaust Fluid Pressure Sensor

To properly manage the emissions from your diesel truck, the right amount of DEF needs to be applied. The DEF Pressure Sensor controls the flow of DEF onto the exhaust, therefore applying the right amount without wasting any. The likely hood of the sensor failing is slim, but if it does and you receive no error code, you should be able to tell by keeping tabs on your DEF levels. If it seems like it's going at a faster than normal rate or that it's not being used enough there's a chance the sensor has gone bad.

Exhaust NOx Sensor

The NOx sensor measures the amount of nitrogen-oxide in the exhaust. Usually, there are two, one at the turbocharger exhaust and one downstream from the DEF injector, however in some cases, there's only one. By measuring the amount of NOx in the exhaust, the truck's computer can adjust the DEF release to maximize efficiency. This sensor needs to be at a certain temperature to operate properly so it'll come equipped with it's own heater. If you receive an error code that it's malfunctioning, I'd recommend making sure the heater is functioning properly first before removing it.

Related Discussion and Articles