What Is P2002?
P2002 is stored on diesel vehicles when the ECU detects that the diesel particulate filter (DPF) has become blocked to the point where it can no longer clean itself efficiently. The DPF traps soot from exhaust gases, periodically burning it off through a process called regeneration. When soot loading exceeds the threshold and regeneration repeatedly fails, P2002 is stored and the car will usually enter limp mode. Ignored long enough, the DPF will need replacing - a very expensive job.
Common Symptoms
- Engine management light on
- Possible limp mode (restricted to 2,000–2,500 rpm)
- DPF warning light (on cars that have one)
- Increased fuel consumption (the ECU injects extra fuel to raise exhaust temperatures for regen)
- Excessive diesel smell
- Black smoke under acceleration
Common Causes
How to Diagnose P2002
Check DPF Soot Loading
Connect OBD scanner and check DPF soot loading percentage. Under 80% is healthy. Over 100% means regen has failed repeatedly.
Attempt Active Regeneration
With a professional scan tool, force an active regen whilst the engine is at operating temperature. This burns off accumulated soot.
Check for Companion Codes
EGR faults, DPF pressure sensor codes, and fuel system codes will all prevent successful regen.
Check Engine Oil Level
If over the max mark, change the oil immediately. Excess oil enters the DPF via blow-by.
Inspect DPF Pressure Sensor
Check DPF pressure sensor and pipes for damage, cracks or blockages.
Verdict
P2002 is serious but not always terminal for the DPF. Catch it early, attempt an active regen, fix any underlying faults, and change your driving habits. Left too long, the DPF will need replacement at significant cost.
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