P2455 on the 6.7L Power Stroke is a diesel particulate filter (DPF) differential pressure sensor A circuit high input fault. The 6.7L measures the pressure difference across the DPF to estimate soot load and schedule regeneration. P2455 sets when the PCM reads that sensor's signal too high, indicating a short to voltage, a lost ground, a blocked or plumbing-reversed hose, or a failed sensor.
Because the DPF pressure signal drives regeneration, a false high reading can make the PCM think the filter is more loaded than it is, triggering unnecessary regens, or it can mask a real condition. P2455 is an electrical circuit code, so the diagnosis starts with the sensor, its wiring, the connector, and the pressure hoses rather than the filter itself. Verifying the circuit and hoses before replacing parts keeps the repair accurate.
What P2455 means
The DPF differential pressure sensor outputs a voltage proportional to the pressure drop across the filter. P2455 sets when that voltage stays at the high end of the scale, indicating a signal wire shorted to voltage or reference, a lost ground allowing the signal to float high, a plugged or reversed pressure hose, or a failed sensor. The PCM loses accurate soot-load data.
Common causes
- Signal wire shorted to reference or voltage
- Open or high-resistance sensor ground
- Plugged, kinked, or reversed pressure sense hose
- Corroded or loose sensor connector
- Failed DPF pressure sensor
Symptoms
- Check engine light with P2455 stored
- Frequent or unnecessary regeneration cycles
- Reduced power or a derate in some cases
- Poor fuel economy
- Companion DPF or exhaust pressure codes
How to diagnose it
View the DPF differential pressure value with a scan tool key on, engine off; it should read near zero. A value pinned high at rest confirms the fault. Inspect the sensor connector for corrosion and a secure fit, and back-probe to confirm a clean ground, since a lost ground commonly causes a high reading. Check the signal wire for a short to voltage or reference. Inspect the pressure sense hoses for plugging, kinks, or reversed connections, which can also drive the reading high.
How to fix it
Restore a poor ground and repair any wiring shorted to voltage or reference first, then clean or replace a corroded connector. Clear or replace plugged or kinked hoses and confirm they are connected in the correct orientation. If the wiring and hoses check good but the signal stays high, replace the DPF pressure sensor. After the repair, clear the code, confirm the sensor reads near zero at rest, and verify regeneration operates normally. For DPF pressure sensors, hoses, and connectors for your 6.7L Power Stroke, contact sales@coredieselparts.com.
Frequently asked questions
Can a plugged hose cause P2455?
Yes. Soot or moisture can plug or kink the pressure sense hoses, skewing the reading high. Inspect and clear the hoses along with checking the sensor and wiring.
Will P2455 cause extra regens?
It can. A false high reading makes the PCM think the DPF is heavily loaded, which can trigger unnecessary regeneration cycles that hurt fuel economy until repaired.
Is P2455 the sensor or the wiring?
Both are possible. Confirm a clean ground and check for a short to voltage, and inspect the hoses. Replace the sensor only if the wiring and hoses are good and the signal stays high.
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