P2003Generic code

P2003 Code: Diesel Particulate Filter Efficiency Below Threshold (Bank 2)

The P2003 code means the bank 2 diesel particulate filter is not trapping soot as it should. The filter may be cracked, punctured or missing. You can drive with caution toward the shop, because a filter that cannot regenerate ends up in limp mode.

Severity
High
Can I keep driving?
Yes, but with caution
Estimated cost
$50 to $2,500
Difficulty
Medium
System
Emissions Control
Applies to
All OBD2 vehicles

Updated Reviewed by Renzo Chacca

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What the P2003 code means

The diesel particulate filter (DPF) traps the soot from a diesel engine. When it fills up, the computer burns the soot off in a regeneration: it raises the exhaust temperature above 550 °C (1,022 °F) for a few minutes, normally while you drive at a steady speed. A differential pressure sensor measures the back pressure across the filter to estimate how much soot it holds.

The P2003 code is set when the computer concludes that the filter is not holding soot, either because the differential pressure is too low for the volume of exhaust gas flowing through it, or because a particulate sensor detects soot downstream of the filter.

Before you replace the filter, rule out the causes that keep it from regenerating: sensors, an EGR valve letting soot through, injectors that drip, a thermostat stuck open, or oil that is not approved for particulate filters. The diesel particulate filter regeneration guide has more detail.

P2003 code symptoms

  • Check engine light or particulate filter warning light on.
  • Loss of power or limp mode.
  • Cooling fan running after you shut the engine off during a regeneration.
  • Higher fuel use.

Likely causes of the P2003 code

  1. Filter cracked or punctured by a regeneration with too much soot in it.
  2. Pressure sensor hoses loose. They give a low reading.
  3. Differential pressure sensor bad. Confirm it by comparing its reading with the real value.
  4. Filter hollowed out or removed. This is illegal in most countries.

How to diagnose the P2003 code step by step

  1. Read the estimated soot load and the differential pressure in live data.
  2. Check the pressure sensor hoses. They crack or get plugged.
  3. Check the exhaust temperature and the EGT sensors.
  4. Check the engine codes. Injectors, the EGR valve and the turbo can all cause excess soot.
  5. Try a forced regeneration with the scan tool, following the manufacturer conditions.

How to fix the P2003 code

  • Do a regeneration on the move: 20 to 30 minutes at a steady speed on the highway.
  • Run a forced regeneration with the scan tool if the soot load allows it.
  • Repair whatever is causing the excess soot.
  • Clean or replace the filter if it is loaded with ash.
  • Use oil that meets the particulate filter specification (low ash).

Technical reference data

  • Regeneration temperature: 550 to 650 °C (1,022 to 1,202 °F).
  • Differential pressure with a clean filter at idle: normally just a few millibars (a small fraction of 1 psi).
  • These values are only a guide, so look up the manufacturer data for your vehicle.

Brand-specific notes

Short city trips are the main enemy of the particulate filter, whatever the brand. The source lists this code as frequent on the diesel vehicles below.

P2003 on Volkswagen, Audi and SEAT

This code is frequent on diesel Volkswagen, Audi and SEAT models.

P2003 on Peugeot, Citroen and Renault

This code is frequent on diesel Peugeot, Citroen and Renault models.

P2003 on Ford

This code is frequent on diesel Ford models.

P2003 on Mercedes-Benz and BMW

This code is frequent on diesel Mercedes-Benz and BMW models.

P2003 on Toyota Hilux, Nissan Navara and Chevrolet

This code is also frequent on the Toyota Hilux, the Nissan Navara and diesel Chevrolet models.

Frequently asked questions about P2003

Can I drive with a P2003 code?
With caution, and toward the shop. A filter that does not regenerate ends up in limp mode.
Can the filter be cleaned?
Yes. Many shops clean filters with dedicated equipment, and it is cheaper than replacing them.
Why does it fill up so fast?
Short trips, injectors or an EGR valve with problems, or oil that is not approved for particulate filters.
How much does it cost to fix P2003?
Roughly $50 to $2,500. A hose or a sensor is at the low end, and a new filter is at the high end.
What does the P2003 code mean?
It is a generic OBD2 code that means the bank 2 diesel particulate filter is not holding soot as it should. The filter can be cracked, punctured or missing, or a hose or sensor can be giving a false reading.
Will a P2003 code clear itself?
Not if the filter is damaged or missing, because the P2003 code will come back. If the cause was a loose hose or a filter that only needed a regeneration, fixing that can clear the code.
What is the most common cause of P2003?
A filter that was cracked or punctured by a regeneration with too much soot in it, or a loose pressure sensor hose giving a false low reading. Check the hoses first because they are cheap.

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