Code
P243F
Generic
P — Powertrain
Particulate Filter Restriction - Soot Accumulation Too High Bank 2
Views:
UK: 18
EN: 96
RU: 27
AI status
Completed
Completed
100%
Causes
- Clogged/sooted diesel particulate filter (DPF) on bank 2
- Failed or inaccurate differential pressure sensor or temperature sensors
- Frequent short trips or low-speed operation preventing regen
- Faulty turbocharger or reduced boost causing incomplete combustion
- Excessive oil or coolant entering the exhaust system (engine issues)
- Exhaust leaks or damaged DPF housing or pipework
Symptoms
- MIL (check engine) illuminated with DPF/soot warning
- Reduced engine power or limp mode
- Poor fuel economy and elevated exhaust temperatures
- Frequent or continuous regeneration events or failed regen attempts
- Black smoke from exhaust under load
- Unusual exhaust smells or visible soot on underside of vehicle
What to check
- Retrieve all stored and pending codes and freeze frame with a capable scan tool
- Check DPF regeneration history and number of forced regens recorded
- Visually inspect DPF and exhaust system for damage, leaks, soot buildup or external blockage
- Inspect differential pressure sensor, exhaust temperature sensors and wiring for damage or contamination
- Check for related codes (EGR, turbo, boost leak, oil consumption, NOx sensors)
- Note driving conditions when fault set (short trips/low load)
Signal parameters
- DPF differential pressure (upstream vs downstream) — elevated when restricted
- Upstream and downstream exhaust temperatures and their response during regen
- DPF soot load estimate (if supported by ECU)
- Intake manifold pressure and turbo boost (low boost can increase soot)
- Engine RPM, load and coolant temperature at time fault set
- Regeneration request/active flag and duration
Diagnostic algorithm
- Connect a scan tool; record freeze frame, live data and all DTCs/pending codes for both banks
- Confirm fault is repeatable: monitor differential pressure and temperatures at idle and under controlled load/run (follow OEM safety procedures)
- Inspect wiring and connectors for DPF differential pressure and temperature sensors; repair any damage and re-test
- Verify turbocharger and intake system for leaks or poor boost; check EGR operation and repair any faults that increase soot production
- If sensors are confirmed good but pressure/soot remain high, perform a forced/active regeneration per OEM procedure in a safe, well-ventilated area and monitor temperatures and pressure drop across DPF
- If forced regen fails or differential pressure remains high, consider removing and visually inspecting the DPF (or using endoscope) for plugged/contaminated substrate or melted/ash accumulation
- If DPF is physically blocked or contaminated beyond cleaning, replace DPF. Replace faulty sensors and wiring as required
- After repairs, clear codes and perform a road test and/or verified regen cycle. Recheck for reoccurrence and confirm normal signal parameters
Likely causes
- High soot load in DPF due to missed/failed regenerations
- Differential pressure sensor out of range or contaminated
- Exhaust temperature sensors giving incorrect readings preventing regen control
- EGR or turbo fault increasing soot production
- Physical blockage (melted catalyst, melted ash layer, debris)
Fault status
Status
Particulate filter restriction — excessive soot accumulation detected on Bank 2
Repair difficulty: Medium
Diagnostic time: 1.0-4.0 hours
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