P2002 Diesel particulate filter efficiency below threshold (bank 1)
What P2002 means
The engine computer compares the pressure before and after the diesel particulate filter (DPF). P2002 means the pressure difference is lower than it should be, which suggests soot is passing through instead of being trapped. This is often caused by a cracked or removed filter, but a faulty pressure sensor or leaking sensor pipe gives the same reading.
P2002 is a generic SAE J2012 code: it means the same on every make. The exact cause still depends on the car, so read the freeze-frame data before replacing parts.
At a glance
- Severity
- Medium
- Typical repair cost
- 150–2000 €
- Workshop time
- 2–8 h
- Repair difficulty
- Hard
- DIY possible
- No
- Check engine light
- Yes
- Affects emissions test
- Yes
- Limp mode possible
- Yes
Parts and labour at an independent workshop in Europe. Main dealers charge more; the cause decides the bill, not the code.
Symptoms
- Check engine or DPF warning light on
- Possible reduced power or limp mode
- Visible black smoke from the exhaust in some cases
- Technical inspection failure for smoke or emissions
Common causes
- Faulty DPF differential pressure sensor
- Cracked, split or disconnected pressure sensor hoses
- Cracked or melted DPF substrate
- Exhaust leak before the DPF
- DPF previously removed or emptied
Can I keep driving with P2002?
You can drive, but book a workshop within one or two weeks. The car may fail a technical inspection, and a damaged filter can let soot through.
What to check first
- Read live differential pressure at idle and at higher rpm; a reading that hardly changes points to the sensor or its hoses
- Inspect the sensor hoses for cracks, blockage or being connected to the wrong ports
- Check for exhaust leaks between the turbo and the DPF
- If the sensor and hoses are good, have the DPF inspected for cracking and replace it if damaged
Related codes
- P2003 Diesel particulate filter efficiency below threshold (bank 2)
- P2004 Intake manifold runner control stuck open (bank 1)
- P2006 Intake manifold runner control stuck closed (bank 1)
- P2008 Intake manifold runner control circuit/open (bank 1)
- P2014 Intake manifold runner position sensor/switch circuit (bank 1)
- P2015 Intake manifold runner position sensor/switch circuit range/performance (bank 1)
- P2017 Intake manifold runner position sensor/switch circuit high (bank 1)
- P203B Reductant (AdBlue) level sensor A circuit range/performance
Data: TORKO fault-code catalogue, built on OBDex (CC0-1.0) and reviewed against workshop practice. Informational only — it does not replace a diagnosis by a mechanic.
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