Maintaining Your Diesel Particulate Filter

Proper maintenance ensures your DPF can regenerate itself when full of soot. There are two types of regeneration: passive and active.

Active Regeneration
Active regeneration involves automatic extra fuel injection when the filter reaches around 45% capacity. This raises the exhaust temperature to burn off the soot. Problems can arise if the journey is too short, preventing complete regeneration. If this happens, the warning light will stay on, indicating a partially blocked filter. To complete the regeneration cycle and clear the warning light, drive for about 10 minutes at speeds over 40 km/h.

Signs of Active Regeneration Include:
Change in engine note
Cooling fans running
Slight increase in fuel consumption
Increased idle speed

Passive Regeneration
Passive regeneration occurs during long, high-speed journeys, such as on motorways, where the exhaust temperature naturally rises to burn off excess soot. Regularly driving at sustained speeds for 30 to 50 minutes helps keep the filter clear.

However, not all drivers frequently engage in such driving. Hence, manufacturers have developed alternative regeneration methods to ensure DPF functionality.