P2456Diesel Particulate Filter Pressure Sensor A Circuit Intermittent/Erratic
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- Needs a drive cycle to confirm a fix
- How the car detects it
- Here the pressure sensor A signal is within range but jumps in a way no real exhaust flow could cause. GM's 2017 and 2018 diesels compare each raw sample with the one before; a step larger than 20 % repeated over 80 or 160 samples sets the code after two trips, but only if no electrical fault is present. VW's 2014 TDI models check the rate of change and flag a pressure moving more than 10 hPa per second against the expected direction. Ford's 2024 gasoline particulate filter strategy files P2456 under its analog circuit checks with a 5 s detection time, and Deutz describes it as erratic differential pressure data. Loose terminals, a chafed harness, water in the sensor or a hose that flutters are the usual triggers. Hard opens or shorts go to P2452, P2454 and P2455; drift is P2453.
- What you may notice
- Malfunction indicator lamp on
- Regeneration started at odd times or blocked
- Likely causes
- LikelyLoose or corroded sensor connector terminals
- PossibleHarness chafing or heat damage near the exhaust
- PossibleCondensate in the sensor or its pressure hoses
- RareSensor element failing internally
- Inspection (ITP)
- Matters for the ITP. While the check-engine light is on, the car fails the emissions check.
- Repair
- Easy · Often possible to do yourself.Typical cost: €30 – €300
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.