The vehicle needs to run at operating temperature during the regeneration, so highway driving is best. Just drive as you normally would. During active regeneration, the exhaust outlet temperature is extremely high. So watch your location if regeneration is about to begin.
Active regeneration
In which case it should be possible to complete a regeneration cycle and clear the warning light by driving for 10 minutes or so at speeds greater than 40mph.
An automatic regen does not require any action by the driver, other than making sure the truck stays ON. It is safe to continue driving as normal. A regeneration cycle typically takes between 10 and 30 minutes to complete.
The most common form is passive regeneration. This occurs while the truck is in motion when the heat of the exhaust burns the soot off the DPF. On the other hand, active regeneration occurs when the exhaust isn't quite hot enough to remove the accumulated soot.
Driving for over 10 minutes at speeds in excess of 40mph will often be sufficient to clear the blockage and regenerate the DPF. You should consult the handbook for your vehicle for more specific guidance on how you should drive to initiate regeneration of the DPF and clear the warning light.
Low speed regeneration is achievable including driving in Low Range. The typical minimum vehicle speed to enable regeneration is 30-40km/h and the higher engine load will assist reaching the minimum exhaust temperatures to enable regeneration of the DPF.
Driving at a speed greater than 40mph for more than 10 minutes should ensure your DPF goes into 'regeneration' mode and clears the blockage.
Failed regeneration usually means extra fuel is injected into the cylinders for active regeneration, which doesn't burn but instead drains into the sump. The results can be severe: loss of oil quality and a higher oil level. This may damage and even destroy the engine.
The DPF regeneration process creates very high exhaust gas temperatures and the exhaust will radiate a considerable amount of heat during and after DPF regeneration, and after you have switched the engine off. This is a potential fire hazard.
Regeneration, or regen, of the DPF filter, is the process that burns the soot accumulation that is inside the DPF filter. If you can no longer start a regen then you will eventually get stuck in a derate which will then lead to an engine shut down.
If your forced DPF regen lasts closer to an hour or continues beyond that, it likely suggests that your exhaust temperatures are not building up high enough to successfully burn off the soot collected in the DPF and that the truck is still trying to bring down those soot levels.
Active DPF regenerations need to burn extra fuel to achieve the high exhaust temperature for soot oxidation, which results in the increased fuel consumption rates.
*set a timer* Wait for the regeneration to start. Monitor the Exhaust temperature and RPM. When the idle comes back down it means that the regen has finished.
Low engine RPM
Alongside the engine not producing much power, the engine may not be able to rev very high, sometimes reaching a top RPM of 3,000. This is a consequence of both the exhaust gases restricting the engine's usual cycle, and because of the lack of turbo pressure.
If the DPF warning light comes on it's because the engine management system needs to 'actively' regenerate the DPF. You should take your car on a run to allow the regeneration process to take place.
Generally, a DPF should last at least 100,000 miles if the vehicle is well serviced and looked after.
Sometimes, a hot and pungent smell can also start coming from your engine as the soot is being burned away. Your stop / start function may also deactivate. Driving for 15 minutes as speeds above 40mph should provide your DPF filter with enough heat to burn away the soot by itself.
How Often Does DPF Regeneration Occur? Active regeneration happens roughly every 300 miles and is triggered by your car's electronic control unit (ECU) once your soot level is approaching 40 to 45%. Passive regeneration should occur when you take your car on longer journeys at higher speeds.
In a Diesel engine with a Diesel particulate filter (DPF) system, high-sulfur fuel causes white smoke containing odorous and harmful pollutants during DPF regeneration.
How long does the regeneration take? The DPF regeneration cycle takes approximately an hour and a half (1 1/2 hours) to complete and can be completed as part of a routine service.
Once the DPF clean has been performed a regen can occur. Whenever it is necessary to perform a forced regen an engine oil change is required after the regen.
Heat the engine
The easiest and cheapest method of DPF filter cleaning is by driving the vehicle for a long-distance at high revs per minute.
Signs of a clogged DPF include reduced engine performance, increased fuel consumption and exhaust emissions… or simply the display of the DPF light in your cockpit.