P2455–P2461 Particulate Filter Pressure Sensor A Circuit High
The voltage on this circuit is sitting near battery voltage. Typically a short to a positive feed, or a disconnected sensor floating high.
Can you drive it? The engine light will stay on and the car may run in a reduced-power mode. Read the freeze-frame data to see the conditions the fault was logged under.
Which code is which
Same fault, different cylinder or bank — diagnosed the same way. Several set together usually means one shared cause.
| Code | Definition | Severity |
|---|---|---|
P2455 | Particulate Filter Pressure Sensor A Circuit High | Investigate soon |
P2461 | Particulate Filter Pressure Sensor B Circuit High | Investigate soon |
The definition
P2455: Particulate Filter Pressure Sensor A Circuit High.
P2455 is a manufacturer-specific powertrain code (the engine or gearbox). Its meaning is set by the carmaker rather than by the SAE standard, so a generic OBD-II reader will often show it as an unknown code or misread it.
What to check first
Cheapest and fastest checks first:
- Unplug the sensor and check whether the signal falls. If it stays high, suspect the wiring rather than the sensor.
- Check the earth path - a missing earth makes a sensor read high.
What actually causes this on a VAG
Same diesel particulate filter differential pressure sensor again - VAG's wording for this code is 'Diesel Particulate Filter Differential Pressure Sensor Circuit High'. Here the signal voltage is sitting above the range the ECU expects. On a five-volt sensor that usually means it is not properly connected, a wire is open - the earth in particular - or the signal line has picked up a voltage it should not have. The ECU treats the reading as untrustworthy and normally stops attempting or completing regenerations while the fault is present, which is what makes this one worth fixing quickly rather than ignoring.
Most likely causes, in order
- Sensor unplugged or plug not latched. The most common finding after any recent work in the engine bay, and it costs nothing to check. Make sure the connector is fully home and the locking tab has clicked, and that nothing has snagged the lead when a cover or pipe was refitted.
- Corrosion or water in the connector. Damp in the plug can bridge pins or eat away a terminal until the circuit is effectively open. Unplug, inspect for green or white deposits and a wet plug body, dry it out, and find where the water is getting in or it will simply come back.
- Open circuit in the sensor earth or signal wire. A broken sensor earth in particular tends to drive the signal to the top of its range, which is exactly what this code describes. Trace the short run from the sensor into the main loom, flexing it, and look for chafing against heat shields and brackets.
- Failed sensor. An internally failed sensor gives the same result. Reasonable to conclude once the plug and the wiring have been checked properly, not as an opening move.
Worth knowing: Do not try to drive this one out with motorway runs. With a sensor the ECU does not trust, a forced or attempted regeneration achieves nothing useful. It also carries a real risk worth understanding: these engines regenerate by injecting extra fuel late in the cycle, and repeated incomplete regenerations wash unburnt diesel past the bores into the sump. Check the oil level on the dipstick while the fault is present - if the level is climbing rather than falling, stop driving the car and have the oil changed along with the repair.
Reading the code is the easy part
A code names the circuit that complained. What tells you why is watching the sensor behind it while the engine runs — and that is where a code reader stops and a diagnostic tool starts.
VAGPULSE reads every module in a VW, Audi, Skoda or SEAT — not just the engine — shows the live measuring blocks behind this fault, gives you the freeze-frame conditions it was logged under, and clears it once you have fixed it. It also does what a generic OBD reader cannot on a VAG: service resets, coding, adaptations, and Stage 1–3 flashing with your original file saved first.
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Common questions
What does P2455 mean?
P2455 means Particulate Filter Pressure Sensor A Circuit High. The voltage on this circuit is sitting near battery voltage. Typically a short to a positive feed, or a disconnected sensor floating high.
Can I drive with P2455?
The engine light will stay on and the car may run in a reduced-power mode. Read the freeze-frame data to see the conditions the fault was logged under.