P2002: Diesel particulate filter efficiency below threshold (bank 1)

What P2002 means

The diesel particulate filter (DPF) traps soot from a diesel’s exhaust. The ECU monitors it by measuring the pressure difference before and after the filter; if the difference is too small, it concludes gases are passing through unfiltered, as if the filter were cracked or missing.

Most common causes

• Differential pressure sensor pipes loose, split or swapped
• Faulty or out-of-calibration differential pressure sensor
• Exhaust leak between the engine and the filter
• Particulate filter cracked or with broken internal material
• Filter replaced or tampered with and the ECU not adapted

Symptoms

• Engine warning light on
• Visible black smoke from the exhaust
• On some cars, loss of power or limp mode
• The car may fail the emissions part of its inspection

Can you drive with P2002?

With care You can drive, but if the filter is not trapping soot the car pollutes more and may fail its inspection. Have it checked soon.

How to check it

With live data, watch the DPF differential pressure: it should rise clearly from idle as you raise the revs. If it barely moves, check the two small pipes from the filter to the sensor before suspecting the filter.

How to read and clear P2002 with Final OBD

Plug an OBD2 scanner in under the steering wheel, switch the ignition on and open Final OBD. Under Faults you’ll see P2002 with this same explanation and whether it’s confirmed, pending or permanent.

With Free you read this code with its short description for nothing, and clear it if the engine stores it over standard OBD. With Pro you get the full explanation, how the car was running when it was logged (revs, temperature, load) and clearing in every control unit.

Clearing the code only turns the light off: if the cause is still there, it comes back. Clear it once it’s fixed, and not right before the ITV. It’s all in how to read and clear fault codes and in the ITV and OBD.

Similar codes

• P2003 Diesel particulate filter efficiency below threshold (bank 2)
• P2004 Intake manifold runner control stuck open (bank 1)
• P2005 Intake manifold runner control stuck open (bank 2)
• P2006 Intake manifold runner control stuck closed (bank 1)
• P2007 Intake manifold runner control stuck closed (bank 2)
• P2008 Intake manifold runner control circuit open or faulty (bank 1)
• P2009 Intake manifold runner control circuit low (bank 1)
• P2015 Intake runner position sensor: range or performance problem (bank 1)

P2002 is a generic code, so it means the same on any make, for example on BMW, Fiat, Ford, Mazda, Peugeot, Volkswagen. See what Final OBD does on your car in makes and models.