P2454: Diesel Particulate Filter Pressure Sensor "A" Circuit Low

P2454 is a emissions-related diagnostic trouble code classified as moderate severity.

• Check engine light on
• Often no change in how the car drives at first
• DPF warning light on some models, sometimes later because regeneration has stopped
• Reduced power or limp mode on some vehicles
• Code may come and go if a damaged wire only touches ground intermittently

Generally yes, for short-term driving. Driveable in the short term, and the car often feels normal at first. Do not leave it for weeks: without a trustworthy pressure signal the engine computer may suspend automatic regeneration or fall back on an estimate, and some cars limit power. A filter that goes too long without regenerating can block, which turns a sensor or wiring repair into a DPF clean or replacement.

1. Read all stored codes and the freeze frame, and note other sensor codes. Several low-voltage codes at once point to a shared 5 V reference or ground rather than the DPF sensor. A generic OBD2 reader shows this code, its freeze frame and standard live data. A few diesels also report DPF differential pressure on a standard PID, but on most cars the pressure reading, the soot load and the regeneration history need manufacturer software, and only manufacturer software or a workshop can run a forced regeneration.
2. Unplug the sensor and inspect the connector for corrosion, water and pushed-back or spread pins.
3. With the key on and the engine off, measure the 5 V reference and the ground at the connector. No reference voltage explains a low signal on its own.
4. With the sensor unplugged and the key off, check the signal wire for continuity to ground. It should have none; a signal wire shorted to ground sets P2454 whatever the sensor does.
5. Follow the harness past the turbo, exhaust and DPF and look for melted or rubbed-through insulation. Wiggle-test it while watching the signal to catch an intermittent short.
6. If the reference, ground and signal wire are all good, the sensor has failed. Fit the correct part for the engine code, run the adaptation if required, clear the code and road-test.