Peugeot 508 Diesel Particulate Filter DPF

The Diesel Particulate Filter (DPF) is an essential component of the Peugeot 508’s exhaust system that captures and filters fine soot particles emitted by the diesel engine to reduce pollution and comply with emissions standards. Made of ceramic, it withstands high temperatures necessary to burn off trapped soot.

The DPF is typically positioned within the exhaust line between the catalytic converter and the rear silencer. This strategic location ensures it reaches the high temperatures needed to effectively burn soot particles during regeneration.

The DPF cleans itself through two regeneration phases:

• Passive regeneration: Occurs naturally during high-speed or high-engine-rpm driving, when exhaust gases reach about 550–600°C and burn off accumulated soot without intervention.
• Active regeneration: Initiated by the engine management system if passive conditions aren't met, by injecting extra fuel to heat the catalytic converter and raise the filter temperature to burn soot.

Regeneration frequency is controlled by the engine computer and typically occurs every 350 to 800 km depending on driving conditions.

The DPF additive is a special fluid that helps lower the combustion temperature of particulates, promoting more efficient regeneration. The additive tank usually requires refilling every 20,000 to 40,000 km depending on driving style and conditions. The engine control unit monitors additive levels to ensure system effectiveness.

Signs indicating potential DPF issues include:

• Noticeable loss of engine power, which is often the first warning.
• Reduced throttle response and difficulties in acceleration.
• Increase in fuel consumption.
• "Service" warning light on the dashboard with a message about risk of filter blockage.

During regeneration, soot is burned and turns into ash, which accumulates over time. The DPF is equipped with pressure sensors before and after the filter to monitor particle load.

• If clogging is excessive and regeneration is ineffective, the engine control unit may limit engine rpm to about 2200 rpm in a "reduced flow mode" to protect the vehicle.

This helps minimize damage but requires intervention to clean or replace the DPF to restore normal operation.

Maintenance operations classified as easy for the Peugeot 508 include:

• Forced regeneration using diagnostic tools.
• Cleaning the DPF to remove soot and ash buildup.
• Replacing the DPF if cleaning is insufficient.
• Refilling the additive tank as required.
• Clearing fault codes and system reset via diagnostic equipment.

Regular maintenance helps ensure efficient filter performance and prevents costly repairs.

This information notably applies to the Peugeot 508 1.6 HDI 110 model produced between 2010 and 2012, featuring an 82 kW (112 hp) engine. For other models, consulting specific documentation or diagnostic data is recommended.

If you experience a DPF warning or suspect clogging, checking live data from the DPF pressure sensor can help diagnose the issue more precisely.