What is a DPF?
DPF stands for ‘Diesel Particulate Filter’ and this plays an important role in diesel engines. DPF’s are designed to trap and store particulate matter (soot) that is produced by the diesel engine during normal driving. The DPF allows exhaust gases (with particulate material) to enter the DPF where the soot is trapped inside the filter, allowing cleaner exhaust gases to exit into the atmosphere, which then reduces the exhaust emissions from the engine.
How Long Should A DPF Last?
A DPF filter should typically last for around 100,000 miles before needing to be replaced. The DPF’s level of maintenance will have a big impact on how much this figure varies. While a well maintained DPF may even go 150,000 miles before needing to be replaced, a badly kept DPF; however, may last a much shorter time than the stated figure. To help extend the life and maintain performance of a DPF, a process known as ‘DPF regeneration’ can be used to clean the filter and restore its performance.
What Are The Types Of DPF Regeneration?
There are two main types of DPF regeneration: passive and active; however, DPF regeneration can be performed manually using a scan tool.
Passive DPF regeneration occurs naturally during normal driving conditions when the temperature of the exhaust gas is high enough to burn off the particulate matter. However, this process is not always effective, especially for vehicles that are used for short trips or in cold weather conditions.
Active DPF regeneration, on the other hand, is a more controlled process that is initiated by the engine control unit (ECU) when the DPF reaches a certain level of saturation. The ECU uses various sensors to monitor the exhaust gas temperature, pressure, and flow rate to determine when active regeneration is necessary. When the DPF is ready for regeneration, the ECU injects additional fuel into the engine to increase the temperature of the exhaust gas and initiate the cleaning process.
During active regeneration, the temperature of the exhaust gas must reach a certain level to burn off the particulate matter that has accumulated in the DPF. This temperature is typically around 600 to 700 degrees Celsius, or 1100 to 1300 Fahrenheit, which is much higher than the normal operating temperature of the engine. To achieve this, the engine may run in a high-idle mode or the vehicle may be driven at higher speeds for a period of time to increase the temperature of the exhaust gas.
How to Regenerate a DPF manually
Manual regeneration is often required when vehicles are driven at insufficient speed to allow regeneration to be carried out automatically by their engine management control software. The vehicle is already suffering with driveability and lack of power problems. At this point, as long as the DPF is not severely blocked (over 90% capacity filled), a scan tool can be used to perform a static or (up to 60% capacity filled) or dynamic regeneration to clear the soot levels in the DPF.