01 Decoding the Engine Control Unit (ECU): Inputs, Outputs, an… • 02 Are Modern Cars Too Complicated? A Real-World Review • 03 Spark Plug Dilemma: Replace All or Just the Bad Ones? Let's… • 04 Why are Catalytic Converters Stolen and How to Prevent It • 05 Types of Chain Drives: Uses, Design, Application, Pros, and… • 06 The Evolution of Exhaust Gas Recirculation (EGR): Reducing … • 07 Can You Change Your Bike's Disc Brake into a Drum Brake? • 08 Unusual Fluid Found Under Vehicles Leaves Drivers Searching… • 09 Signs Your Car Needs an Oil Change and Oil Top-Up: Warnings… • 10 Pros and Cons of Using a Mortgage Loan to Buy a Car: What Y… •

DTC codes / P24xx · Auxiliary emission controls / P2455

P2455Diesel Particulate Filter Pressure Sensor Circuit High

P2455 indicates that the engine control module has detected an abnormally high voltage signal from the diesel particulate filter pressure sensor circuit, which typically means the sensor is reporting a pressure higher than physically possible or the circuit is shorted to voltage. The computer sets this code when the signal voltage exceeds the expected range for the current operating conditions, often indicating a wiring fault, a failed sensor, or a blocked passage.

SystemPowertrain
Code typeGeneric (all makes)
SeverityMedium
Fix difficultyIntermediate
AreaAuxiliary emission controls

Symptoms you may notice

  • Illumination of the check engine light, often with no other noticeable symptoms.
  • Reduced engine power or limp mode in some vehicles as a protective measure.
  • A message on the dash indicating a diesel particulate filter fault or service required.
  • Possible poor fuel economy or increased regeneration frequency.
  • In rare cases, a noticeable hesitation or rough running if the fault affects regeneration strategy.

Common causes, most likely first

  1. Failed diesel particulate filter pressure sensor sending an incorrect high voltage signal.
  2. Short to voltage in the sensor signal circuit or reference circuit.
  3. Corroded, damaged, or disconnected electrical connector at the sensor or ECM.
  4. Blocked or restricted pressure sensor hose or port, causing a false high reading.
  5. Exhaust system blockage or severe soot accumulation creating excessive backpressure.
  6. ECM internal fault or software issue misinterpreting the sensor signal.

How to diagnose and fix it

  1. Perform a visual inspection of the pressure sensor, its wiring, and connectors for damage or corrosion.
  2. Use a scan tool to read live data from the DPF pressure sensor and compare it to key-on, engine-off expectations.
  3. Check the sensor reference voltage and ground circuits with a multimeter to rule out wiring faults.
  4. Inspect and clean the pressure sensor hoses and ports for blockages or cracks.
  5. Test the sensor with a known good unit or perform a resistance check if specifications are available.
  6. Verify exhaust backpressure with a gauge to rule out a clogged DPF or exhaust restriction.
  7. Clear the code and perform a road test to confirm the repair, monitoring for code return.

Don't overlook the pressure hoses

  • A common oversight is replacing the pressure sensor when the real problem is a cracked or clogged rubber hose that connects the sensor to the exhaust stream.
  • The code can be set by a short to voltage in the wiring harness where it rubs against a sharp edge, which is often missed during a quick visual inspection.
  • A severely clogged DPF can cause the pressure sensor to read high, mimicking a sensor fault, so always check exhaust backpressure before condemning the sensor.
  • On some vehicles, a faulty ECM or a software glitch can cause a false high signal, requiring a reflash or replacement after all other causes are ruled out.
  • The sensor may test fine statically but fail intermittently when exposed to heat or vibration, so a wiggle test and live data monitoring during a road test are essential.

Can I keep driving with P2455?

It is generally safe to drive with this code as long as the vehicle is not in limp mode and no other severe symptoms are present, but avoid prolonged driving because a blocked DPF can lead to more expensive damage. Schedule a diagnostic appointment soon to prevent potential regeneration issues.

Tools that help

Tools we recommend are in the Auto Veteran shop on Amazon. As an Amazon Associate we earn from qualifying purchases.

Guidance is general and written for all OBD-II vehicles. Exact tests and values vary by model, so confirm the fault before replacing parts.

Running on fumes Free guides aren't free to make. Top up the tank. Any amount, one time. Fuel the Garage