P242FParticulate Filter Restriction - Ash Accumulation (Bank 1)
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- Can trigger limp mode
- How the car detects it
- P242F reports that so much incombustible ash has collected in the bank 1 particulate filter that it restricts flow and no regeneration can clear it. Ash comes mainly from oil additives, builds up over the service life and leaves the filter only through cleaning or replacement. Deutz stores P242F-00 as a high ash load warning on its EMR L1 controller. GM's 2018 diesel tables watch for the same condition but file it under P24A4, which GM labels ash accumulation: a filtered flow resistance from differential pressure and exhaust flow, 5 failures in 10 samples, Type A. On 2015 Ram 2500/3500 with the 6.7 L Cummins, Stellantis issued PCM software (18-037-16) because P242F could set with no defect present, so check the calibration first. Soot overload belongs to P2463; the second filter has P243A.
- What you may notice
- MIL or DPF service message
- Regenerations becoming more frequent
- Loss of power at high load due to back pressure
- Likely causes
- LikelyFilter has reached its ash capacity after high mileage or operating hours
- PossibleHigh oil consumption or unsuitable oil (high ash content) speeding up ash build-up
- PossibleCalibration setting the code without a defect (Ram 6.7 L 2015, bulletin 18-037-16)
- RareDifferential pressure sensor or hoses reporting too much restriction
- 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: €0 – €3,000
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.