Diesel particulate filter (DPF)
P2002 and P2003: understanding DPF efficiency faults
P2002 and P2003 report an assessment of particulate-filter efficiency. They differ in the bank concerned. Neither code alone means the filter is full or identifies a replacement part.
At a glance
What the codes tell you
- P2002
- Particulate filter efficiency below threshold (bank 1).
- P2003
- Particulate filter efficiency below threshold (bank 2).
How the entries differ
- In the standard definition, P2002 refers to bank 1.
- P2003 describes the same assessment for bank 2.
- The engine and exhaust layout determine which banks exist and which one is involved.
What is not yet established
- An efficiency warning is not a measurement of soot or ash mass.
- The code does not distinguish between filter condition, sensor readings and operating conditions.
- The code describes the control unit’s assessment. It determines neither which component needs replacing nor the repair required.
- Manufacturer-specific descriptions, status, freeze-frame data and live readings can materially change the interpretation.
Diagnostic information that helps next
A reliable assessment does not consider the code in isolation. The following information turns a number into a fault condition that can be investigated:
- Full diagnostic-tool description, including status and bank
- Freeze-frame data with engine speed, load and temperatures
- Differential pressure and exhaust temperatures under the relevant operating conditions
- Regeneration history and calculated soot and ash values
More codes for this system
Frequently asked questions about P2002, P2003
What do fault codes P2002, P2003 mean?
P2002: Particulate filter efficiency below threshold (bank 1). P2003: Particulate filter efficiency below threshold (bank 2).
Which component needs replacing for P2002?
The code does not determine that. The full diagnostic description, fault status, freeze-frame data, live readings and vehicle-specific system checks determine the appropriate repair.
What information helps with diagnosis?
Useful information includes Full diagnostic-tool description, including status and bank, Freeze-frame data with engine speed, load and temperatures, Differential pressure and exhaust temperatures under the relevant operating conditions, Regeneration history and calculated soot and ash values.
Traceable sources
Sources and scope
The descriptions are our own factual explanations of standardised generic OBD definitions. Manufacturer-specific P1xxx codes and differing manufacturer descriptions are not given blanket interpretations here.