1. Diesel Particulate Filter failure-“DPF” failure is a SYMPTOM of an aftertreatment problem, not THE problem
  2. Understanding how the DPF works will help you understand how to prevent premature DPF failure
  3. You can minimize DPF failure with some easy steps and modern maintenance

For many fleet managers, the diesel particulate filter, or DPF, is the biggest headache to deal with. Since emission control systems, aka aftertreatment, became a requirement in 2010, fleets have struggled to keep their trucks on the road. Commonly, trucks end up de-rated or broken down due to aftertreatment failure. The most common component to blame is the DPF. However, DPF failure is actually a symptom of aftertreatment problems, not necessarily the problem.

How the DPF Works

If you can really understand how the DPF works, and what it is designed to do, then you will have a better understanding of how to prevent DPF failure. The DPF was designed to reduce pollutants and contaminents in diesel exhaust. The DPF is a large ceramic filter that is designed to capture exhaust soot. By trapping soot, the exhaust that exits the engine has minimal pollutants in it. Prior to DPF’s, you would typically see black smoke billowing out of an exhaust stack. Black smoke is exhaust that is full of pollutants. With a DPF, that black smoke is captured, and “tailpipe” emissions are greatly reduced. If your DPF is constantly plugging, then it is a symptom of either an issue with another aftertreatment component causing excessive exhaust pollutants, or there is a problem with passive regens. It is often times a combination of the two.

Why DPF Failure Happens

First, let’s define what we mean by DPF “failure”. DPF failure is when the DPF is no longer able to properly function, and must be totally replaced. Complete DPF failure occurs when long term progressive damage has caused irreparable harm to the integrity of the filter elements. PREMATURE DPF failure is different. Premature DPF failure is when the DPF does not meet the manufacturer recommended cleaning interval. For example, a Cummins ISX15 engine’s DPF is designed to last between 400,000-600,000 miles before requiring a cleaning! Is your DPF reaching the manufacturer cleaning interval? Probably not. However, when a DPF fails prematurely, it usually just needs to be cleaned and reinstalled.

The reason your DPF fails prematurely is simply because it is doing its job. It is capturing exhaust soot and pollutants, and is plugging up. The real question should be: “Why is this happening so frequently?”

If your DPF is constantly plugging, then it is a symptom of either an issue with another aftertreatment component causing excessive exhaust pollutants, or there is a problem with passive regens. It is often times a combination of the two.

What is Actually Causing Your DPF to PlugCummins DPF failure-Diesel Fleet Solutions

Excessive DEF, excessive oil, and especially incomplete or inefficient regenerations are the problem. Excessive DEF and oil consumption typically comes from upstream aftertreatment failure to dosers or the EGR, for example. These problems can be mitigated with aftertreatment specific maintenance training through Diesel Fleet Solutions.

The easiest and most comprehensive way to prevent premature DPF failure, however, is by enabling the aftertreatment system to function properly, in conjunction with aftertreatment specific maintenance training. Enabling the aftertreatment to work properly is done through the proper application of manufacturer recommended features and parameters. When enabled properly for your specific application, the aftertreatment will finally be able to operate as designed and properly regen. With proper and efficient regens, the DPF will actually stay clean. Additionally, the rest of the system won’t have to work extra fighting against a constantly dirty DPF. This reduces your overall repairs and progressive damage.

Cummins is the premier engine manufacturer when it comes to providing owner’s with the ability to improve fleet efficiency, because through the use of Cummins Insite, owner’s are able to make the necessary and required ECM changes. This DOES NOT require a dealership (although it is worth questioning why the dealership wouldn’t have made these changes for you, considering how important they are for proper aftertreatment and DPF reliability). Unfortunately, not all engine manufacturers provide this type of owner capability to improve their fleet.

The most important ECM changes will improve the ability of your truck to passively regen, when needed, regardless of duty cycle. Efficient and complete regens are necessary to keeping the DPF clean, and reaching manufacturer intervals. Without a properly enabled aftertreatment system you will always face common aftertreatment issues:


  • recurring fault codes
  • forced regens
  • derates
  • premature turbo failure
  • EGR failure
  • SCR failure
  • check engine lights
  • DEF waste and overuse
  • lost efficiency
  • increased downtime

Again, these issues are essentially eliminated with simple correct ECM programming and proper aftertreatment maintenance training.

How Do I Fix My DPF?

You need to program your ECM properly, according to manufacturer recommendations. This will allow the aftertreatment system to finally work as designed and keep the DPF clean. The applications that have the most problems with this are in the vocational field. Stop-and-go, delivery, refuse, etc…however, the problem also exists in over-the-road. Diesel Fleet Solutions provides the information, training, and support to empower fleets to properly manage emission compliant trucks. Our consulting program teaches you the nuances of modern diesel fleet maintenance, and gives you actionable and legal solutions to the most common problems. It starts with ECM programming.


Take the 15 minute challenge. It is simple:

  1. using Cummins Insite, download the most recent work order ECM image of your Cummins engine
  2. save it as an “.eif”
  3. email it to: support@dieselfleetsolutions.com
  4. please include:
    1. contact info
    2. fleet name and address
    3. fleet size
    4. specific issues with this truck

Our team will provide you with a quick ECM audit that will confirm the need for proper programming (or in 1% of cases, confirm that your ECM is programmed correctly and that you have a different problem). One of our consultants will contact you to tell you exactly what is wrong, and exactly what you need to do to fix your DPF. Between sending us the image, and implementing our recommendation, you will have improved your DPF in less than 15 minutes.


We are sick of naysayers, and we are also sick of good fleets struggling in these challenging times, when they can be helped. So for now, this offer is FREE. The challenge is, are you ready to break away from the “Dealer Mentality”? Take back control of your fleet with information, training, and support from Diesel Fleet Solutions.


*currently only available for emission compliant, Cummins model engines; must have Cummins Insite in order to provide image download and implement solution





Recommended Posts