Diesel Combustion & Emission Control System Within

How does it work?

Let’s start with the combustion process, air contains 78% nitrogen and 20.8% oxygen. If it’s compressed to a small space fast, the air becomes super heated and we spray diesel fuel into the hot compressed air and we will get a combustion.

NOX gas (Nitrogenoxyde)

What else will we get? We get quite a lot of NOX gas (nitrogenoxyde) which is an irritant pollutant gas hazardous to human health.

Diesel Engine Issues

The common NOX sensor issue at hand.

The usual phone call starts like this, I have a Diesel Mercedes or BMW and my car is telling me I have an incorrect fluid in my reduction system.

Diesel exhaust emission system test and the test
results with the failed components.
Click on the thumbnail to view bigger image.

Let’s clarify a few things.
#1; Your Diesel vehicle has no AI (artificial intelligence) it has a computer system which is programmed by humans, so it can only tell you what it knows or gets feedback, so consecutively it will tell you what has been programmed to tell you.

#2; When the information system tells you your vehicle has an incorrect fluid in it, 99.99% it is lacking of SCR (selective catalyst reduction) system efficiency. It means one thing, your computer system doesn’t see the emission reduction of the NOX gas, so it will automatically default by blaming the quality of the ad blue (urea) SCR fluid as it is programmed to do so.

SCR Fluid Reservoir

Before you drain your entire SCR fluid reservoir it can be tested (by a professional) for fluid strength which has 13% ammonia solution.

The emission system on modern diesels is very complex. I could write here pages and pages how the EGR system with the SCR injection and the NOX catalyst working together to effectively reduce the amount of NOX gases.

Suffice to say, if your reduction system doesn’t work properly, or the computer doesn’t see the efficiency, due to dead NOX sensors or myriad other SCR issues at hand, will default to a single message as per above.

In case, the driver ignores the warning long enough the computer will start a no start count down, where the system control will eventually refuse to start the engine and must be towed to have it repaired properly.

Please keep a few important points in mind. Any emission component is expensive due to high tech nature, and many cases contain pricey precious metals to split or control spent exhaust gases effectively, working in a hot corrosive and hostile environment.

Any questions how may we help?

Call us for details: Telephone: 905.795.0419


European Imports Diesel Service in Techmax Auto Repair Inc.

Join us on Social Media.

Techmax on LinkedIn