P246D code meaning
Particulate Filter Pressure Sensor A/B Correlation
Powertrain system Generic code P24xx codes Check engine light
What P246D means
P246D compares two pressure readings at the particulate filter that ought to agree under steady conditions. Which sensor is A and which is B is decided by each manufacturer. Ford's 2013 to 2015 diesel summaries use it as a rationality test between the filter pressure sensor DPFP and the delta pressure sensor DPS: with coolant above 70 °C, ambient pressure above 745 hPa, filter inlet temperature between 125 and 425 °C and exhaust flow of 200 to 600 kg/h, the code sets once the two differ by over 1.5 kPa, evaluated over about 2 s. Typical findings are swapped, kinked or leaking sensing hoses, water in a line or one sensor drifting while its circuit still passes. Pure electrical faults have their own codes (P2452 ff. and P245E ff.). With a doubtful pressure value the soot estimate and regeneration timing suffer.
P246D at a glance
- Check engine lightYes, usually on
- Emissions testCan fail
- Limp modeNot expected
- Repair difficultyMedium, DIY possible
- Typical labor0.3 to 2 hours
- Clears after repairAfter a drive cycle
Symptoms of P246D
- MIL on
- Regeneration too early, too late or suspended
- Pressure values of the two sensors disagree in live data
Common causes of P246D
- Most likelySensing hoses swapped, kinked or leaking
- PossibleWater or soot in a sensing line
- PossibleOne pressure sensor drifting out of calibration
Check the most likely causes first. Replacing parts by guesswork is the most expensive way to clear a code.
Parts involved
DPF pressure sensor aDPF pressure sensor b
What each part of P246D 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). |
| 6D | The exact fault in that area. |
What to do next
- Note P246D 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 P246D
What does P246D mean?
P246D means "Particulate Filter Pressure Sensor A/B Correlation". P246D compares two pressure readings at the particulate filter that ought to agree under steady conditions. It is a generic code, so it means the same on every make.
Is it safe to drive with P246D?
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 P246D fail an emissions test?
Yes, it can. P246D 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 P246D to fix?
Difficulty: medium. A typical repair takes 0.3 to 2 hours of work. A careful DIY repair is possible with basic tools and a scanner.
Will P246D 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.