Are you avoiding the high costs associated with new yard truck regulations?
Many of our customers we poll are buying late model trucks and staying away from newer models that include Advance EGR or SCR (urea) technology. They choose to buy late models because they believe it is a safer investment. Many are now seeing DPF for the first time and have asked why must we have DPF in both on and off highway trucks. Here is a quick overview and some answers to common questions.
What is a DPF?
A diesel particulate filter (DPF) is a device which is inline with the exhaust system designed to catch diesel particulate matter or soot from the exhaust gas to prevent them from being released into the atmosphere. A diesel particulate filter can remove upwards of 85% of the particles from the exhaust, reducing harmful emissions in the process. The DPF physically captures the soot and ash particles in a mesh-like structure within the filter.
What does the DPF warning light on my dash mean?
The DPF warning light displayed on the dash indicates that the filter is not working correctly or is in need of maintenance/regeneration. Sensors within the device monitor the back pressure and temperature of the system to ensure it is working correctly. When the readings from these sensors are outside a pre-programmed limit, they will trigger the warning. Once activated, the light should trigger a regeneration cycle of the filter or could indicate that the device is faulty and in need of repair.
DPF Regeneration on a terminal truck
There are three different types of DPF regeneration that are commonly used. These are active, passive and forced.
Active regeneration of the DPF is performed by the ECU triggering a post combustion fuel injection. This increases the temperature in DPF, burning off the soot and particles that build up in the filter. This type of regeneration can cause higher than normal fuel usage.
Passive regeneration takes place automatically on motorway-type runs when the exhaust temperature is high. Many manufacturers have moved to using active regeneration as many operators do not often drive prolonged distances at motorway speeds. Passive regeneration often uses a DPF additive.
Forced regeneration is a way of cleaning the DPF using a maintenance process which has been built in by the manufacturer. This process can only be started by a dealer/mechanic with the right tools and access to the vehicle’s management systems. This process usually involves kicking off a DPF clean cycle in the workshop which runs the engine at a high RPM for a considerable period of time. The Electronic Control Unit (ECU) ensures that this cycle heats the DPF to an extreme temperature, burning off the contents of the filter. In some cases, the ECU injects fuel into the post-combustion process to achieve these temperatures. In most cases the engine oil will need to be changed as the vehicle will literally “cook” the lubricant.
DPF cleaning is a manual process that removes the soot and particulates from the filter. DPF cleaning is often achieved by utilizing ultrasonic cleaning technology in combination with specialized chemicals. This process removes all particulates, returning it back to near new condition. There are many companies offering DPF cleaning service, many which offer a guarantee, free collection and return. Having your DPF cleaned is certainly a viable alternative to replacing the entire unit, considering the cost of replacement.
What should I do when I see the DPF warning light?
At the first instance, contact your manufacturer’s service center. Depending on the model and make of your truck, the process of regenerating the filter will differ. Failure to correctly regenerate the filter in a timely manner can lead to a costly manual regeneration, or in the worst case – failure of the device. You can find regeneration tip cards in our support center for both Capacity and Ottawa terminal tractors.