P2002

Diesel Particulate Filter Efficiency Below Threshold Bank 1

P2002 is a generic OBD-II powertrain diagnostic trouble code: Diesel Particulate Filter Efficiency Below Threshold Bank 1. It is logged by the engine control unit when the dpf monitor detects that a specific fault threshold has been exceeded — typically resulting in the malfunction-indicator lamp (MIL / check-engine light) being illuminated.

Code
P2002
Group
Powertrain
System
DPF
Severity
Warning (MIL on, possible limp mode)
Need P2002 disabled?
RaceTune permanently disables any OBD-II trouble code on supported ECUs — for motorsport, off-road, and export use.
→

What P2002 means

P2002 is a generic SAE powertrain code that sets when the engine control unit decides the Diesel Particulate Filter (DPF) on bank 1 is no longer trapping soot efficiently enough to meet emissions limits. The ECU reaches that conclusion by comparing the differential pressure across the filter (and on many vehicles temperature and soot-load models) against expected values during and after a regeneration cycle. If the filter cannot clean itself back down to a healthy state, or the pressure signature looks wrong for the calculated soot mass, the monitor flags the efficiency as below threshold and stores P2002.

The code is specific to diesel vehicles fitted with a DPF, so it shows up on light-duty diesels from manufacturers such as Volkswagen, Audi, BMW, Mercedes-Benz, Ford, GM, Ram and Peugeot/Citroen, as well as on heavier diesels. It is one of the most common DPF-related faults and frequently appears on cars used mainly for short urban trips, where the exhaust never gets hot enough to complete a passive regeneration.

P2002 is typically accompanied by the check engine light and, on many vehicles, a separate DPF warning lamp. Depending on how loaded the filter has become, the ECU may also place the engine into a reduced-power or limp mode to protect the after-treatment system until the fault is addressed.

Common causes

Most-frequently reported root causes when P2002 is logged.

  • 1
    Excessive short-trip or stop-and-go driving that prevents the DPF from completing a regeneration cycle.
  • 2
    A physically clogged or ash-loaded DPF that can no longer be cleaned by normal regeneration.
  • 3
    Faulty DPF differential pressure sensor or damaged pressure hoses giving incorrect readings to the ECU.
  • 4
    Exhaust leaks upstream of or around the DPF that disturb the pressure and temperature signals.
  • 5
    A failed or cracked DPF substrate that lets soot pass through instead of trapping it.
  • 6
    Faulty exhaust gas temperature sensors preventing the ECU from running or validating regenerations.
  • 7
    Use of incorrect engine oil or high-sulfur fuel, leading to excessive ash build-up inside the filter.
  • 8
    Outdated ECU software where the manufacturer has issued a regeneration strategy update.

Symptoms drivers notice

Check engine light is on, often together with a dedicated DPF warning lamp.
Noticeable loss of power or the vehicle dropping into limp mode under acceleration.
Reduced fuel economy compared with normal operation.
Visible black soot from the tailpipe or a strong exhaust smell.
Hard starting or rough running, particularly when the filter is heavily loaded.
Engine oil level rising or smelling of diesel due to repeated failed regeneration attempts.

How to diagnose P2002

A typical diagnostic flow when this code is present.

  1. 1
    Scan the vehicle for all stored and pending codes and record freeze-frame data, since related sensor or EGR codes often point to the real cause.
  2. 2
    Read live data for DPF differential pressure, exhaust gas temperatures, calculated soot load and distance since last regeneration to see how the filter is behaving.
  3. 3
    Visually inspect the exhaust system for leaks, damaged clamps, and the DPF pressure hoses for cracks, blockages or incorrect routing.
  4. 4
    Check the DPF differential pressure sensor and exhaust temperature sensors against manufacturer specifications before condemning the filter.
  5. 5
    If soot load is moderate and no other faults are present, attempt a scan-tool-commanded forced regeneration following the manufacturer procedure.
  6. 6
    If forced regeneration fails or ash load is too high, remove the DPF for inspection, professional cleaning, or replacement as required.
  7. 7
    Check for and apply any manufacturer software updates for the engine control unit related to DPF regeneration strategy.

Vehicles where we've handled P2002

Platforms in our catalogue with confirmed P2002 coverage.

VW TOURAN 20D
BMW 320D
2016
AUDI A6
2015
AUDI A6 30D
2015
AUDI A7
AUDI A7 30D

Related powertrain codes

Frequently asked questions

Is it safe to keep driving with a P2002 code?

Short trips to a workshop are usually fine, but continued driving with a clogged DPF can cause the engine to enter limp mode, dilute the engine oil with unburned diesel, and ultimately damage the filter to the point where it must be replaced rather than cleaned.

Can I clear P2002 just by driving on the highway?

Sometimes. If the filter is only moderately loaded and there is no underlying sensor or mechanical fault, a sustained run at higher engine load and speed can let the ECU complete a regeneration and clear the code. If P2002 returns, there is a deeper problem that needs diagnosis.

Does P2002 always mean the DPF needs to be replaced?

No. In many cases the filter itself is fine and the code is caused by short-trip driving, a faulty pressure or temperature sensor, an exhaust leak, or out-of-date ECU software. The DPF should only be replaced after these have been ruled out.

How much does it typically cost to fix P2002?

Costs vary widely. A forced regeneration or sensor replacement is relatively inexpensive, professional DPF cleaning is moderate, and a full DPF replacement on a modern diesel can be one of the most expensive emissions repairs on the vehicle.

Disabling P2002 in software

RaceTune can permanently disable P2002 — and any other OBD-II diagnostic trouble code — on every ECU family we support. The monitor is disabled inside the ECU itself, so the fault stops being logged: the warning light stays off and the engine never enters limp mode for this code. The change is tied to your exact software version.

Permanent
The monitor is disabled in the ECU itself — not just cleared. It cannot return.
Tailored to your file
Each patch is matched to your specific software version — never a one-size-fits-all file.
Reversible
The original file is always preserved. Reflash the stock to return the ECU to factory state.

ECUs with a P2002 disable in our catalogue

Confirmed coverage from our recipe database — we support many more families. Upload your file and our identifier will match it automatically.

  • Bosch EDC17C50 verified 1 software version
  • Bosch EDC17C60 verified 1 software version
  • Bosch EDC17C74 verified 1 software version
  • Bosch EDC17CP09 verified 1 software version
  • Bosch EDC17CP44 verified 1 software version
  • Bosch MD1CP004 verified 1 software version

Software modifications affect emissions compliance and are not road-legal in many jurisdictions. RaceTune service files are intended for motorsport, off-road, and export use.

Got P2002 in your scan?

Upload your ECU file — we'll identify the exact software version and confirm whether a disable is available for your car.

Upload your file