P2455Powertrain
Powertrain · SAE
DPF Differential Pressure Sensor — Signal High
Meaning
The DPF differential pressure sensor signal exceeds the maximum permitted threshold. The ECU interprets the voltage as too high, indicating a short to supply voltage, a failed sensor, or an actually very high filter pressure due to clogging.
Common causes
- Short circuit of the signal wire to supply voltage (5 V or 12 V)
- Internally failed differential pressure sensor (output stuck high)
- DPF actually clogged with pressure differential beyond measurement range
- Partially blocked sensor pressure line amplifying the reading
- Internal short circuit in the connector
Symptoms
- Check engine light on
- DPF pressure value fixed at maximum or out of range on scan tool
- Forced regeneration triggered excessively frequently
- Possible power reduction for system protection
- Related codes P2452, P2463, or P244A possible
Severity
Moderate to high: if the high signal is real (clogged DPF), severe engine damage is at risk; if it is a false signal, continuous regenerations can damage the DPF itself.
What to do
- Measure sensor output voltage (typical 0.5–4.5 V); if above 4.5 V, investigate the short to supply
- Check sensor wiring with multimeter for shorts to the supply line
- Disconnect the sensor and measure differential pressure with an external gauge to verify actual DPF state
- Inspect pressure lines for partial blockages
- Replace the sensor if wiring is intact but signal remains high