Renault Vel Satis Diesel Particulate Filter DPF (2001-2009)

The Diesel Particulate Filter (DPF) on the Renault Vel Satis is a mechanical anti-pollution device located after the catalytic converter and before the silencer in the exhaust system. It traps up to 99% of soot particles produced by diesel fuel combustion to reduce emissions and comply with environmental standards.

The DPF consists of a ceramic body divided into about 50 microscopic channels per cm² arranged in parallel. Exhaust gases pass through these channels while soot particles are trapped inside, allowing only gases to exit through the filter.

The DPF cleans itself through three types of regeneration:

• Passive Regeneration: Happens automatically when the engine runs at full load, using the combustion chamber's heat to burn off trapped soot.
• Active Regeneration: Triggered by the engine control unit during low load when sensors detect pressure buildup. It raises exhaust gas temperature using EGR valve adjustments, post-injection, and turbo management to convert soot into carbon dioxide, water vapor, and ash. This occurs every 500 to 700 km and lasts 5 to 15 minutes.
• manual Regeneration: Performed using diagnostic tools, helpful for urban or short trips to clean the DPF manually.

This process ensures the DPF remains efficient and avoids clogging, maintaining engine performance and reducing emissions.

The DPF diagnostic system includes several key parts:

• The DPF unit itself (the large canister)
• A differential pressure sensor that measures pressure before and after the DPF
• Upstream and downstream sensor pipes

The sensor identifies the pressure difference to monitor filter function and detect blockages or faults.

Common issues include:

• Faulty differential pressure sensor
• Leaks or damage to sensor pipes
• DPF wear or clogging

The generic error code P2002 indicates that the diesel particulate filter efficiency is below the required threshold, signaling potential filter malfunction or contamination.

On the Vel Satis 2.0 dCi, repairs typically involve replacing or fixing the pressure sensor and its pipes. The process is as follows:

• Hold the lock nut and unscrew the sensor fitting
• Use a flaring tool similar to brake line installation
• Reposition the sensor and tighten the retaining bolt

This ensures accurate pressure measurement and restores proper DPF function.

Replacing the DPF on a Renault Vel Satis 2.2 dCi 150 hp typically requires about 2 hours and 4 minutes of labour time. This process should be done using quality original parts to ensure compliance with emission standards and maintain engine performance.

Yes, a few important points to consider:

• Some very fine nanoparticles may not be fully trapped by the DPF, posing health risks upon inhalation.
• Using additives like AdBlue can lower the combustion temperature of soot particles by about 100°C, helping regeneration even when engine load is low.
• Some Vel Satis 2.0 litre 150 hp models have reported DPF shape or hardness issues due to unique 'L-shaped' designs with limited availability of exact replacement parts.

Regular maintenance and proper driving conditions are crucial to ensure efficient DPF operation, lower emissions, and optimal engine power with reduced black smoke.