DPF Additive Low Warning: What It Means and How We Can Help

If you’re seeing warnings like “Engine fault: Have the vehicle repaired” or “Particle Filter additive level too low” on your dashboard, you’re not alone. These messages are especially common in Peugeot, Citroën, Ford, and Volvo vehicles that use the DPF additive system, often referred to as Eolys fluid or the PATS system.

These alerts typically appear around the 100,000-mile mark, and the good news is—they’re completely fixable.

What Is the PATS or Eolys Additive System?

Modern diesel vehicles are equipped with a Diesel Particulate Filter (DPF) to help reduce emissions. To keep the DPF working efficiently, manufacturers like Peugeot and Citroën use an additive called Eolys fluid, which is automatically injected into the fuel tank to assist with DPF regeneration.

This system is sometimes referred to as PATS (Particle filter Additive Tank System) and is also found in some Ford and Volvo models that share platforms with PSA engines.

Why does it matter? 

This fluid helps lower the temperature at which soot burns, allowing the DPF to regenerate effectively

Ignoring this warning can lead to several problems, including:

• A decrease in engine power.
• Worsened fuel economy.
• The vehicle potentially entering "limp mode" (reduced performance to prevent further damage).

In the worst-case scenario, a completely blocked DPF, which can result in costly repairs.
Therefore, it's crucial to address this warning promptly to avoid more severe issues with your vehicle's DPF system.

Common Fault Codes:

If you’ve had a diagnostic scan done, you might have seen one or more of the following fault codes:

• P1445 – Additive adding: The quantity of additive injected into the particle emission filter has exceeded the maximum threshold. (This often means the DPF may also be blocked.)
• P15B3 – Calculated additive level below the critical threshold
• B2EB000 – Additive reservoir empty fault

These are permanent faults, and will not clear until the underlying issue is resolved.

What Causes the Warning?

Over time and mileage, the vehicle uses up the fluid in the additive tank. Once it runs low or dry, the vehicle’s ECU will log a fault and display the dashboard warnings.

You may also notice:

• Loss of power
• Reduced fuel economy
• The car going into limp mode (in severe cases)

How We Can Help

At TGPP-Autocare Stevenage, we offer a complete additive system service, including:

✅ Refilling the Eolys fluid

✅ Resetting the additive counter

✅ Checking for DPF saturation or blockage

✅ Clearing fault codes once the issue is resolved

We use OE-grade fluid and professional diagnostic tools to ensure your vehicle is fixed properly the first time.

Is It Safe to Drive With This Warning?

You may still be able to drive short distances, but continuing to do so can lead to a blocked DPF, which is a much more expensive repair. It’s best to get it looked at as soon as the warning appears.

Book Your Vehicle In Today

If you’ve seen either of the following on your dash:

📟 “Engine fault: Have the vehicle repaired”

📟 “Particle Filter additive level too low”

Then give us a call at TGPP-Autocare Stevenage. We’ll refill and reset your PATS system quickly and professionally.

Common DPF Additive System Fault Codes

• P1445 – Additive adding: The amount injected has exceeded the max threshold. DPF may be saturated.
• P15B3 – Additive level below critical threshold.
• B2EB000 – Additive reservoir is empty or below minimum.
• P1435 / P1434 – Additive system communication fault (less common, but related).

These codes are logged when the vehicle’s PATS or Eolys system needs refilling and resetting.

We’re based in Stevenage, serving customers from across Hertfordshire, Letchworth, Welwyn Garden City, Hatfield, and surrounding areas. Whether you drive a Peugeot 3008, Citroën Berlingo, Ford Transit, or a Volvo V50, we can help with Eolys and DPF additive faults.