P243AParticulate Filter Restriction - Ash Accumulation (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
- P243A is the bank 2 counterpart of P242F: the ash load in the second particulate filter has grown so large that the filter chokes the exhaust and must be cleaned or replaced. A bank 2 filter only exists where each cylinder bank of a V engine feeds its own filter strand. No manufacturer documents this exact code publicly. Bank 1 monitoring shows how such a check works: GM's 2018 diesels judge ash by a filtered flow resistance derived from differential pressure and exhaust flow (Type A), and Deutz raises a warning once a modelled ash load limit is passed. Since ash does not burn, extra regenerations will not help and only waste fuel. If only one strand shows high back pressure or regenerates more often, the problem is confined to that side.
- What you may notice
- MIL or filter service message
- Higher fuel consumption from frequent regenerations
- Reduced power at high load
- Likely causes
- LikelyBank 2 filter full of ash after long service
- PossibleOil burning on bank 2 (valve stem seals, turbo seal) adding ash
- RareBank 2 pressure sensor or hose 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: €300 – €3,000
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.