Diesel Particulate Filter
Traps soot from the exhaust in a honeycomb of porous channels, and periodically burns it off — regeneration — to clear itself. The burning-off is the part that goes wrong, because it needs sustained exhaust heat that short, cold journeys never produce. A filter that never completes a regeneration loads up gradually, and the vehicle attempts regeneration more and more often until the filter blocks.
That sequence is slow enough that nobody connects cause to effect, which is why the early signs matter: fuel consumption creeping up, regenerations happening more frequently, and oil level rising rather than falling — the last being diesel washing past the rings during failed regeneration attempts, which dilutes the oil and can damage the engine well before the filter itself fails.
Soot burns off; ash does not. Ash comes from oil additives and accumulates permanently, so every filter has a finite life no amount of regeneration extends — a filter at the end of its ash life needs replacing rather than cleaning, and that is a different finding from one merely clogged with soot.
Also known as: dpf, particulate filter, soot filter, fap, diesel filter, gpf, petrol particulate filter
Referenced by 76 codes
Codes involving this component (76)
- P20CF Exhaust Aftertreatment Fuel Injector A Stuck Open Stop driving Critical
- P20DB Exhaust Aftertreatment Fuel Supply Control Stuck Open Stop driving Critical
- P032F Combustion Engine Producing Insufficient Torque High
- P214D SCR NOx Catalyst Outlet Temperature Too High During Particulate Filter Regeneration High
- P226D Particulate Filter Deteriorated/Missing Substrate Bank 1 High
- P242F Particulate Filter Restriction - Ash Accumulation Bank 1 High
- P244D Exhaust Temperature Too High For Particulate Filter Regeneration Bank 1 High
- P24A4 Particulate Filter Restriction - Soot Accumulation Too High Bank 1 High
- P2698 Exhaust Aftertreatment Fuel Injector A Performance High
- P045E Exhaust Gas Recirculation B Control Stuck Open Moderate
- P04DA Closed Loop Exhaust Gas Recirculation Control At Limit — Flow Too High Moderate
- P242B Exhaust Gas Temperature Sensor Circuit Range/Performance Bank 1 Sensor 3 Moderate
- P244A Particulate Filter Differential Pressure Too Low Bank 1 Moderate
- P245F Particulate Filter Pressure Sensor B Circuit Range/Performance Moderate
- P24A2 Particulate Filter Regeneration Incomplete Bank 1 Moderate
- P24AE Particulate Matter Sensor Circuit Moderate
- P24AF Particulate Matter Sensor Circuit Range/Performance Moderate
- P24B0 Particulate Matter Sensor Circuit Low Moderate
- P24B1 Particulate Matter Sensor Circuit High Moderate
- P24B2 Particulate Matter Sensor Circuit Intermittent Moderate
- P24C2 Exhaust Gas Temperature Measurement System - Multiple Sensor Correlation Bank 1 Moderate
- P24DA Particulate Matter Sensor Exhaust Sample Error Bank 1 Moderate
- P2584 Fuel Additive Control Module Requested Malfunction Indicator Lamp Illumination Moderate
- P2585 Fuel Additive Control Module Warning Lamp Request Moderate
- P2697 Exhaust Aftertreatment Fuel Injector A Circuit/Open Moderate
Other components in Exhaust and Emissions
- Oxygen Sensor 326
- EGR Valve 150
- Catalytic Converter 142
- NOx Sensor 118
- Reductant Injector 107
- Exhaust Gas Temperature Sensor 95
- Reductant Tank 95
- SCR Catalyst 65
- EGR Cooler 62
- Exhaust Gas Differential Pressure Sensor 58
- Fuel Tank Pressure Sensor 58
- Exhaust Pressure Control Valve 56
- Reductant Heater 55
- Reductant Pump 51
- EVAP Vent Valve 43
- Exhaust Aftertreatment Fuel Injector 42
- Charcoal Canister 33
- EGR Position Sensor 32
- Secondary Air Injection Pump 32
- Reductant Temperature Sensor 29
- EVAP Leak Detection Pump 29
- EVAP Purge Valve 27
- Particulate Matter Sensor 24
- Reductant Control Module 24
- Reductant Level Sensor 23
- Secondary Air Switching Valve 22
- EGR Temperature Sensor 21
- Secondary Air Check Valve 21
- Catalyst Heater 20
- Catalyst Temperature Sensor 20
- Fuel Filler Cap 18
- EGR Cooler Bypass Valve 16
- Reductant Quality Sensor 16
- Exhaust Back Pressure Sensor 15
- Purge Flow Sensor 13
- Direct Ozone Reduction Catalyst 13
- EGR Vacuum Solenoid 9
- Fuel Vapour Temperature Sensor 5
- Fuel Additive Control Module 4
- Fuel Additive Tank 4
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