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P2002 – Particulate Filter Efficiency Below Threshold – OM651 (Mercedes-Benz OM651)

Fault code P2002 means "Particulate Filter Efficiency Below Threshold – OM651". It is common on OM651 (C/E/GLK/Vito/Sprinter 180–250 CDI), OM642 V6 CDI engines. Below are the real-world causes, step-by-step tests and OEM part numbers.

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P2002 quick summary

Fault codeP2002
MeaningParticulate Filter Efficiency Below Threshold – OM651
SystemPowertrain (Engine & Transmission)
VehiclesMercedes-Benz
Common onOM651 (C/E/GLK/Vito/Sprinter 180–250 CDI), OM642 V6 CDI
SeverityMedium
Can I drive?Yes, but have it checked. A faulty sensor can stop regenerations, and a cracked filter fails the emissions test.
Repair cost€30 – €2,500

Symptoms of P2002

  • Check Engine light
  • Often no noticeable power loss
  • Black soot at the tailpipe (cracked filter)
  • Regenerations not running or running too often
  • Sometimes P2452–P2455 (differential pressure sensor) alongside

Most common causes of P2002 (most likely first)

Mechanic's Pro Tip

P2002 means the ECU thinks the filter is NOT filtering well – the pressure difference across it is too low. On Mercedes diesels the differential pressure sensor and its two hoses are a common cause: a cracked hose or a failing sensor gives exactly this reading. Check them before you condemn the DPF. Soot inside the tailpipe after the filter points to a cracked filter.

  1. 1.Faulty differential pressure sensor

    Most likely

  2. 2.Cracked, disconnected or swapped sensor hoses

  3. 3.Cracked or melted particulate filter

  4. 4.Exhaust leak before the filter

  5. 5.Filter removed or tampered with

Step-by-step diagnostic guide

  1. 1

    Read all codes with XENTRY or a Mercedes-capable scanner and note related DPF and sensor codes.

  2. 2

    Check the differential pressure in live data: a few mbar at idle, rising clearly with rpm. A value stuck near zero points to the sensor or hoses.

  3. 3

    Inspect both sensor hoses and connections.

  4. 4

    Look for soot in the tailpipe and exhaust leaks before the DPF.

  5. 5

    If sensor and hoses are fine, have the filter checked or replaced and reset the DPF adaptation.

Frequently asked questions

What is the difference between P2002 and P2463 on a Mercedes?

P2463 means the filter is too full of soot. P2002 means it is filtering too little – usually a sensor or hose problem, or a damaged filter.

How much does it cost to fix P2002 on an OM651?

A sensor hose costs a few euros, a differential pressure sensor about 50–150 €. A new DPF costs roughly 1,000–2,500 € fitted depending on the model.

Related fault codes

This guide is for information only. Working on vehicles can be dangerous — if you are unsure, have the car checked by a qualified mechanic. Values can differ between model years; always check the manufacturer's repair information.