Fault codes › Powertrain › Generic (SAE standard) › Fuel and air metering, plus auxiliary emission controls
P2002 Diesel particulate filter efficiency below threshold
Needs attention Have it looked at soon. The car is usually driveable with care in the meantime.
What does P2002 mean?
P2002 is a generic powertrain code, defined by the SAE standard, so it means the same thing on every make and model: diesel particulate filter efficiency below threshold. It belongs to the fuel and air metering, plus auxiliary emission controls group of codes.
A control module stores the code when something it watches stays outside what it expects for long enough. On its own the code says which system complained, not which part has failed — the causes below, most likely first, are where to start.
Is it safe to drive with P2002?
Needs attention. A longer, steady trip often lets it regenerate; if it recurs, have it inspected.
Common causes of P2002
- Soot-loaded filter from short journeys.
- Failed differential pressure sensor.
- Cracked filter substrate.
Symptoms
- Reduced power.
- DPF warning.
- Frequent regeneration attempts.
What to check first
- Differential pressure readings.
- Successful forced regeneration.
- Filter condition.
Can I just clear P2002?
You can, and the light goes out — but a fault that is still there sets the code again, often within a drive or two. Clearing also erases the freeze frame (what the engine was doing when the code was stored) and resets the emissions readiness monitors, so an MOT, smog or inspection test will wait until they have run again. Fix the cause first, then clear it, then watch whether it returns.
Read and clear P2002 from your iPhone with OBDTrip
Plug a Bluetooth OBD-II adapter into the car and OBDTrip reads every stored, pending and permanent code, explains each one in plain English like this, shows what the engine was doing when it was set, and clears the check engine light once the fault is fixed. It keeps a history of when each code comes back, and records every drive on its own from then on.
Needs a Bluetooth Low Energy adapter such as the Vgate iCar Pro — which adapters work with iPhone. Reading and clearing codes is part of an OBDTrip subscription.
Related codes
- P2096 Post-catalyst fuel trim system too lean (bank 1)
- P0010 Camshaft position actuator circuit (bank 1)
- P0011 Camshaft position — timing over-advanced (bank 1)
- P0016 Crankshaft/camshaft position correlation (bank 1)
- P0030 Oxygen sensor heater circuit (bank 1, sensor 1)
- P0071 Ambient air temperature sensor range/performance
General guidance from OBDTrip's fault-code catalogue, not a diagnosis of your car. When a code points to brakes, steering, overheating or a flashing check engine light, have the car looked at before driving on.