P243C code meaning
Particulate Filter Regeneration Frequency (Bank 2)
Powertrain system Generic code P24xx codes Check engine light
What P243C means
P243C is stored when the bank 2 particulate filter needs regeneration more often than its calibration allows. CARB requires diesel OBD to recognise regeneration so frequent that emissions would rise above the limit. No manufacturer documents this bank 2 code publicly, so the bank 1 code P2459 serves as the reference: Ford's 2023 diesels flag it once completed regenerations occur, on average, less than roughly 40 km apart. Excess soot from the engine side of that bank, for example a leaking injector, an EGR or boost fault, or a pressure reading that overstates the load, makes the filter look full too early. Every extra regeneration burns fuel and can thin the engine oil. If the other bank regenerates at normal intervals, compare what differs on this side.
P243C at a glance
- Check engine lightYes, usually on
- Emissions testCan fail
- Limp modeNot expected
- Repair difficultyHard
- Typical labor1 to 5 hours
- Clears after repairAfter a drive cycle
Symptoms of P243C
- Regeneration running unusually often
- Higher fuel consumption, rising oil level
- MIL on
Common causes of P243C
- Most likelyToo much soot from bank 2 cylinders (injector, EGR or boost fault)
- PossiblePressure sensor or hose overstating the bank 2 soot load
- PossibleFilter partly filled with ash, leaving little soot capacity
Check the most likely causes first. Replacing parts by guesswork is the most expensive way to clear a code.
Parts involved
DPF b2Fuel injectors
What each part of P243C means
| P | Powertrain system: engine, fuel system, ignition, emissions and transmission. |
| 2 | Generic code (second SAE range): it means the same on every make. |
| 4 | Area: auxiliary emission controls (catalytic converter, EGR, EVAP). |
| 3C | The exact fault in that area. |
What to do next
- Note P243C and any other codes stored with it: several codes together often point to one cause.
- Check for loose connectors and damaged wiring around the parts the code names.
- Check open recalls for your car: some faults are fixed for free by the dealer. Enter your VIN.
- Clear the code only after the repair. If it comes back, the fault is still there.
Buying a used car? Scan it for stored codes before you pay. A recently cleared memory can hide a problem.
Questions about P243C
What does P243C mean?
P243C means "Particulate Filter Regeneration Frequency (Bank 2)". P243C is stored when the bank 2 particulate filter needs regeneration more often than its calibration allows. It is a generic code, so it means the same on every make.
Is it safe to drive with P243C?
Usually yes, for a short time, if the check engine light is steady and the car drives normally. If the light flashes or the car runs badly, stop and have it checked.
Will P243C fail an emissions test?
Yes, it can. P243C is emissions-related, so most inspection programs fail a car while it is stored or while the check engine light is on.
How hard is P243C to fix?
Difficulty: hard. A typical repair takes 1 to 5 hours of work. This is a job for a workshop.
Will P243C clear itself after the repair?
After the repair the car has to complete a drive cycle (a mix of city and highway driving) before the test runs again. Until then the readiness monitor shows "not ready", which can fail an inspection.