P2002 — Diesel Particulate Filter Efficiency Below Threshold (Bank 1)
Moderate severityWhat it means
P2002 is stored when the engine control unit sees a fault involving the diesel particulate filter (DPF) efficiency on bank 1. The diesel particulate filter traps soot from the exhaust and burns it off during regeneration; this code means its efficiency on bank 1 has dropped below the threshold.
Common symptoms
- Reduced power or limp mode
- Frequent or failed regenerations
- Check engine light
Likely causes
- A clogged or aged DPF
- Lots of short trips preventing regeneration, or a sensor fault
What to check first
- Read DPF soot load and pressure in live data
- Attempt a forced regeneration and check the pressure sensor
Can you keep driving?
Often drops to reduced power; a long steady drive can help it regenerate, but diagnose soon to avoid a blocked filter.
Frequently asked questions
What is the most common cause of P2002?
The most likely cause is: A clogged or aged DPF. Several other faults can set P2002 as well, so confirm the real cause with live data and the checks above before replacing any parts.
Can I just clear P2002 and keep driving?
Clearing P2002 with an OBD2 scanner turns the warning light off, but if the underlying fault has not been repaired the code will usually come back within a few drive cycles. Fix the cause first, then clear the code to confirm the repair worked.
How serious is P2002?
P2002 is a moderate-severity code. The car is often still drivable, but have it diagnosed soon — the underlying problem can get worse and it may fail an emissions test.
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