P2455: Diesel Particulate Filter Pressure Sensor A Circuit High

What it means

Voltage on the DPF pressure sensor line exceeds the upper threshold. Usually a short to supply or an open ground on the sensor.

At a glance

• Usually lights the check-engine light
• Affects emissions; the car can fail an emissions test

How it works

DPF pressure Sensor A measures pressure difference across the filter for the engine control module's soot-load and regeneration calculations. P2455 sets when Sensor A's signal voltage rises above the upper circuit threshold, leaving the pressure value unreliable.

Common causes

Most likely first.

1. Signal shorted to supply
2. Sensor ground open
3. Connector pins corroded - high contact resistance

Symptoms

• Check engine light or DPF warning light on
• Power loss / limp mode
• Increased fuel consumption
• Failed forced regeneration attempts

How to diagnose it

1. Review freeze-frame data and Sensor A live data to confirm the signal is high when the fault sets.
2. Inspect Sensor A's connector and harness for corrosion, damaged insulation, or a signal wire shorted to a supply circuit.
3. Check the sensor ground connection for a loose, damaged, or open ground.
4. Using the manufacturer's wiring diagram, measure Sensor A's reference, ground, and signal circuits to distinguish a short to supply from a failed sensor.
5. If the circuits are sound but the signal remains high, test Sensor A with the manufacturer's procedure and replace it if it fails.

Common fixes

• Repair a signal wire shorted to supply.
• Restore an open or poor Sensor A ground connection.
• Clean or repair corroded connector pins and damaged wiring.
• Replace DPF pressure Sensor A if it fails circuit testing.

Can I keep driving?

Do not rely on the vehicle's DPF soot-load estimate while Sensor A is reporting a high circuit signal. Arrange diagnosis soon, and limit driving if a DPF warning or power loss appears because regeneration may not work correctly.