P243FParticulate Filter Restriction - Soot Accumulation Too High (Bank 2)
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- Can trigger limp mode
- How the car detects it
- P243F means the soot load estimated for the bank 2 particulate filter has climbed past the level that a normal regeneration can still handle safely. Burning off too much soot at once can overheat and crack the substrate, so many engines then block automatic regeneration and call for a service regeneration or a new filter. No manufacturer documents P243F publicly. For the bank 1 analogue P2463, GM's 2018 diesels estimate soot from the differential pressure and confirm the fault after 120 failures in 150 samples; the same GM table, oddly, labels P24A4, the J2012 bank 1 twin of P243F, as ash accumulation. Typical causes are long stretches of short trips or idling, regenerations that keep aborting and engine faults that raise soot output on that bank. Power reduction (P243B) may follow.
- What you may notice
- MIL and filter warning on
- Automatic regeneration blocked, service regeneration needed
- Reduced power possible
- Likely causes
- LikelyRepeatedly aborted regenerations, short trips or long idling
- PossibleEngine fault raising soot output on bank 2 (injector, EGR, boost)
- RarePressure sensor or hose overstating the soot load
- Inspection (ITP)
- Matters for the ITP. While the check-engine light is on, the car fails the emissions check.
- Repair
- Hard · Usually a job for a workshop.Typical cost: €100 – €3,000
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.