P24A2

Code

Generic P — Powertrain

Particulate Filter Regeneration Incomplete Bank 1

Brand: Generic

Type: P — Powertrain

Views: UK: 22 EN: 92 RU: 28

AI status

Completed

ready

Completed 100%

Page language: EN

Causes

Exhaust leaks upstream or at DPF flange disrupting temperature/flow
DPF heavily clogged or saturated with soot/ash
Faulty differential pressure (DPF) sensor or contaminated sensor
Faulty exhaust gas temperature sensor (upstream or downstream)
Regeneration process interrupted (operator braking, low battery, low fuel, or ECU abort)
Low exhaust temperature due to turbocharger or intake/EGR faults

Symptoms

Malfunction Indicator Lamp (MIL) illuminated
Active or frequent forced-regeneration requests
Reduced engine power or limp-home mode on severe restriction
Poor fuel economy
Soot/black smoke from tailpipe during attempted regen
Strong diesel/soot odor during or after failed regen attempts

What to check

Read and record all stored and pending DTCs and freeze-frame data with a capable scan tool.
Check DPF soot load, regeneration status, and related live data (DPF differential pressure, exhaust temps, soot %, regen cycles).
Verify monitor readiness and recent regen history (time, distance, last forced regen).
Visually inspect exhaust system for leaks or damaged flanges, clamps and flex sections upstream of the DPF.
Inspect wiring and connectors for DPF pressure and temperature sensors and repair any damage or corrosion.
Measure differential pressure across the DPF at idle and under load; compare to manufacturer values.

Signal parameters

DPF differential pressure (mbar or kPa) — normally low at idle; should drop after successful regen
Exhaust gas temperature upstream of DPF (°C) — should reach regen threshold (typically several hundred °C depending on system)
Exhaust gas temperature downstream of DPF (°C) — rises during regen; should show significant change
Calculated soot load or soot mass (%) — elevated values indicate need for regeneration
Engine load / RPM / throttle position — regen requires adequate load or RPM threshold
Battery voltage (V) — adequate voltage required to complete active regen (>12.5–13 V typical)

Diagnostic algorithm

Connect a professional scan tool. Record freeze-frame data, all related DTCs and live DPF/regen parameters.
Confirm vehicle operating conditions and last regen history. Ask driver about recent driving (short trips vs sustained highway).
Perform visual inspection for obvious exhaust leaks, damaged DPF hardware, or tampered components.
Verify electrical integrity: check wiring and connectors for DPF pressure and temperature sensors, repair as needed.
Measure DPF differential pressure at idle and under load; compare to published limits. High differential pressure supports filter restriction.
Check exhaust temperatures before and after DPF during a controlled forced regen. If temperatures do not reach expected regen values, investigate turbo, EGR, intake, and fueling.
Attempt a forced/active regen while monitoring parameters and noting any abort codes/events. If regen completes and values normalize, clear codes and perform road test to confirm.
If forced regen fails and sensors read correctly, suspect internal DPF plugging or high ash load — consider professional DPF cleaning or replacement after confirming with pressure and soot data.
Replace any failed sensors (DPF differential pressure, exhaust temp) or repair wiring and re-attempt regeneration.
After repair, clear codes, confirm readiness monitors, and verify that regenerations complete normally over a drive cycle.

Likely causes

High soot load in DPF preventing completion of active regen
DPF differential pressure sensor giving incorrect high reading
Exhaust temperature sensor failed or reading low preventing the ECU from reaching regen temperatures
Short trips or conditions that prevent the vehicle reaching required load/temperature for regen
Exhaust leak upstream of DPF causing false sensor readings and insufficient heat across the filter

Fault status

⚠️ Status

ECM detected an incomplete particulate filter regeneration sequence on Bank 1. The event and related freeze-frame data are logged; MIL may be set and regeneration requests or reduced power events may occur until regeneration is successful or a repair is performed.

🟡 Repair difficulty: Medium

⏱️ Diagnostic time: 1-4 hours