P2455 — Diesel Particulate Filter Pressure Sensor A Circuit High
Moderate severityWhat it means
P2455 is stored when the engine control unit sees a fault involving the diesel particulate filter (DPF) pressure sensor circuit. The DPF differential pressure sensor tells the control unit how clogged the filter is, which drives regeneration; a fault can stop regenerations or trigger false ones. A “high” reading means the signal is pinned near the top of its range — often an open circuit, a lost ground, or a short to voltage.
Common symptoms
- The live reading sits abnormally high or maxed out
- Regeneration problems or limp mode
- Reduced power
- Check engine light
Likely causes
- Open signal or ground wire
- Signal wire shorted to a voltage supply
- A faulty DPF pressure sensor
- Blocked or split pressure hoses, or a wiring fault
What to check first
- Check for an open circuit or missing ground at the sensor connector
- Compare the sensor reading at idle with a known-good value
- Inspect the pressure hoses for blockage or leaks
Can you keep driving?
Often drivable, but failed regenerations can clog the DPF — diagnose soon, especially on a diesel.
Frequently asked questions
What is the most common cause of P2455?
The most likely cause is: Open signal or ground wire. Several other faults can set P2455 as well, so confirm the real cause with live data and the checks above before replacing any parts.
Can I just clear P2455 and keep driving?
Clearing P2455 with an OBD2 scanner turns the warning light off, but if the underlying fault has not been repaired the code will usually come back within a few drive cycles. Fix the cause first, then clear the code to confirm the repair worked.
How serious is P2455?
P2455 is a moderate-severity code. The car is often still drivable, but have it diagnosed soon — the underlying problem can get worse and it may fail an emissions test.
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