How does the Ford DEF system work?
The Ford Diesel Exhaust Fluid (DEF) system is a key component of modern diesel engines that helps reduce harmful emissions. This system injects a urea-based solution, known as DEF, into the exhaust stream to convert nitrogen oxides (NOx) into harmless nitrogen and water. By understanding how the Ford DEF system works, vehicle owners can ensure their diesel engines operate efficiently and comply with environmental regulations.
What is the Ford DEF System?
The Ford DEF system is a selective catalytic reduction (SCR) technology that is used in Ford's diesel vehicles to meet stringent emissions standards. The system works by injecting a urea-based solution, known as diesel exhaust fluid (DEF) or AdBlue, into the exhaust stream. When the DEF mixes with the hot exhaust gases, it undergoes a chemical reaction that converts harmful nitrogen oxides (NOx) into nitrogen and water, which are then expelled through the vehicle's exhaust.
How the Ford DEF System Works
The Ford DEF system consists of several key components:
- DEF Tank: This is where the urea-based DEF solution is stored. The tank is typically located in the rear of the vehicle and is refilled as needed.
- DEF Injector: The DEF injector is responsible for spraying the DEF solution into the exhaust stream. It is controlled by the vehicle's engine control unit (ECU) to ensure the correct amount of DEF is injected.
- DEF Dosing Module: This module monitors the DEF level and quality, and communicates with the ECU to ensure the proper amount of DEF is being injected.
- DEF Quality Sensor: This sensor checks the concentration of the DEF solution to ensure it meets the required specifications.
- Catalytic Converter: The catalytic converter in the exhaust system is where the chemical reaction between the DEF and the exhaust gases takes place, converting NOx into harmless nitrogen and water.
The Ford DEF system works by continuously monitoring the vehicle's operating conditions and adjusting the amount of DEF injected into the exhaust stream accordingly. This ensures that the correct amount of DEF is used to effectively reduce NOx emissions and keep the vehicle in compliance with environmental regulations.
Maintaining the Ford DEF System
To ensure the Ford DEF system continues to function properly, it is important to regularly check and maintain the system. This includes:
- Refilling the DEF Tank: The DEF tank should be refilled as needed, typically when the low DEF warning light illuminates on the dashboard.
- Checking the DEF Quality: The DEF quality should be checked periodically to ensure it meets the required specifications. This can be done using a DEF quality test kit.
- Inspecting the System Components: The various components of the DEF system, such as the injector, dosing module, and sensors, should be inspected for any signs of wear or damage and replaced as needed.
By properly maintaining the Ford DEF system, vehicle owners can help ensure their diesel engines continue to operate efficiently and comply with environmental regulations.
Is DEF injected into the exhaust stream?
DEF is injected into the diesel exhaust stream and the heat from the exhaust, the fluid and a catalyst converts the NOx into harmless gases. DEF is a 32.5% solution of automotive grade pure urea in purified water. For the SCR unit to operate efficiently, the DEF must meet exceptional standards of purity.
Does DEF shorten the life of a diesel engine?
If DEF enters the fuel system and spread throughout the engine it will ruin the diesel engine eventually. The fuel system lines are not compatible with DEF and slowly corrode and over time.
What is one of the most common problems in the DEF system?
Here are some of the most common diesel exhaust fluid problems diesel owners may encounter:
- Contaminated or Degraded DEF.
- DEF Crystallization.
- Frozen DEF Lines.
- Signs of Contaminated DEF.
- Effects on the Emissions System.
- Common Sensor Failures.
- Frozen DEF Lines.
- Common DEF Pump Failures.
How many miles will 1 gallon of DEF last?
between 300 to 500 miles
Most DEF tanks require one gallon of DEF for every 50 gallons of diesel fuel, and one gallon will generally last between 300 to 500 miles. It is important not to allow the DEF tote to become completely empty. It should be refilled when 2-3 inches of DEF remains in the tote.
Is it bad to idle a diesel with DEF?
The ravages of idling can result in significant mechanical degradation and excessive fuel consumption. Many crucial components of the engine, such as the Engine Gas Recirculation (EGR) valve and Diesel Exhaust Fluid (DEF) filter, can be damaged while the vehicle is idle.
Is there an additive to keep DEF from freezing?
It is not recommended to add any sort of additive to DEF to prevent freezing, as this will prevent the fluid from performing as designed. The use of contaminated or non-manufacturer approved DEF may result in costly after-treatment system repairs. DEF is a mixture of 67.5% de-ionized water and 32.5% purified urea.
