Common DPF Fault Codes
DPF fault codes and what they usually point to.
These codes are a starting point, not a diagnosis on their own. Live data, pressure readings, temperature readings and the vehicle history all matter before cleaning or replacing parts.
DPF and regeneration codes
| Code | Common meaning | What we check |
|---|---|---|
| P1471 | Diesel particulate filter regeneration not completed. | Regen enable conditions, soot load, temperature data and any engine faults blocking regeneration. |
| P2002 | Diesel particulate filter efficiency below threshold on bank 1. | DPF loading, exhaust leaks, pressure sensor readings and whether the vehicle has completed recent regenerations. |
| P2003 | DPF efficiency or particulate mass fault on bank 1. | Air leaks, fuel quality, pressure readings and soot or ash loading. |
| P242F | DPF restriction, ash accumulation or regeneration not active. | Ash load, pressure sensor operation, blocked pressure pipes and failed regeneration history. |
| P2458 | Maximum regeneration time exceeded. | Why the regen is taking too long: temperature, soot load, driving conditions, engine faults or sensor data. |
| P2459 | Regeneration frequency implausible. | Repeat regen triggers, short journey patterns, pressure readings, injectors, EGR and thermostat operation. |
DPF pressure sensor and differential pressure codes
| Code | Common meaning | What we check |
|---|---|---|
| P0470 | Exhaust pressure sensor malfunction. | Blocked sensor pipe, damaged hose, wiring, connector condition and live pressure readings. |
| P0471 | Exhaust pressure sensor range or performance fault. | EGR faults, intake or exhaust leaks, sensor drift and pressure data against engine load. |
| P244A | Particulate filter differential pressure too low. | Split or disconnected pressure pipes, wiring faults, sensor operation and previous DPF work. |
| P244B | Particulate filter differential pressure too high. | Blocked DPF, blocked pressure pipes, sensor accuracy and exhaust restriction. |
| P2452 | Particulate filter differential pressure sensor malfunction. | Sensor supply, signal, earth, pipe condition and live-data plausibility. |
| P2453 | DPF differential pressure sensor malfunction. | Intermittent sensor readings, wiring, connector corrosion and pressure hose blockage. |
| P2454 | DPF differential pressure sensor voltage too low. | Low signal voltage, wiring faults, sensor power supply and possible short circuits. |
| P2455 | DPF differential pressure sensor malfunction or voltage fault. | High signal voltage, wiring faults, sensor failure and pressure pipe condition. |
Exhaust gas temperature sensor codes
| Code | Common meaning | What we check |
|---|---|---|
| P2031 | Exhaust gas temperature sensor circuit fault. | Sensor wiring, connector condition, broken wires and temperature data. |
| P2032 | Exhaust gas temperature sensor low signal. | Low reading causes, wiring faults, connector corrosion and failed sensor checks. |
| P2033 | Exhaust gas temperature sensor high signal. | High reading causes, open circuit faults, connector issues and sensor response. |
Do not guess from the code alone
The same code can have more than one cause.
A blocked DPF code can be caused by the filter, but it can also be caused by a pressure sensor, split pipe, failed temperature sensor, EGR fault, injector issue, thermostat problem or previous software work.
Send us the code list, registration, warning message and what work has already been tried. We will help you choose the right next step.
Ask DPF Wales