P2455 — Diesel Particulate Filter Pressure Sensor "A" Circuit High

What are the symptoms of P2455?

Drivers most often notice: Check Engine or DPF warning light on, loss of power and limp mode, frequent regeneration attempts, increased fuel consumption.

What does OBD2 code P2455 mean?

OBD2 code P2455 flags a problem with the diesel particulate filter (DPF) (diesel particulate filter pressure sensor "A" circuit high). Short, gentle driving to a shop is usually possible. Common culprits: excessive ash loading (end of DPF life), failed regeneration due to sensor or wiring faults, faulty differential pressure or exhaust temperature sensor.

How much does it cost to fix P2455?

Replace a pressure or temperature sensor — $150–$450; DPF replacement — $1,500–$4,000; Forced regeneration / cleaning — $150–$400. Exact cost depends on the root cause, your vehicle and local labor rates — a proper diagnosis is the cheapest first step.

What is the most common cause of P2455?

The most common causes are: excessive ash loading (end of DPF life), failed regeneration due to sensor or wiring faults, faulty differential pressure or exhaust temperature sensor.

How do I diagnose P2455 myself?

Start with a scan: confirm P2455, save the freeze frame and note any companion codes. Then inspect the wiring and connectors related to the diesel particulate filter pressure sensor "A", and verify the suspect component against live data before buying parts.

What does P2455 mean?

P2455 (Diesel Particulate Filter Pressure Sensor "A" Circuit High) is stored when self-diagnostics detect abnormal readings or behaviour of the diesel particulate filter (DPF). It belongs to the powertrain (engine/transmission) category.

“Circuit high” means the control module sees a voltage on the diesel particulate filter pressure sensor "A" circuit that is above the expected range — typically close to battery voltage. Physically this points to a short to a power feed, a broken ground return, or a failed component pulling the signal line high.

To set P2455, the control module compares live readings of the diesel particulate filter (DPF) against calibrated limits, usually over several drive cycles. Alongside the code it stores a freeze frame — a snapshot of rpm, load, coolant temperature and vehicle speed at the moment of failure. Reading that snapshot first saves diagnostic time.

Common symptoms of P2455

• Check Engine or DPF warning light on
• loss of power and limp mode
• frequent regeneration attempts
• increased fuel consumption
• rising oil level from fuel dilution

What causes P2455?

• open ground return of the diesel particulate filter pressure sensor "A"
• failed diesel particulate filter pressure sensor "A" pulling the signal high
• signal wire shorted to battery positive
• engine faults producing excess soot (EGR, injectors)
• excessive ash loading (end of DPF life)
• faulty differential pressure or exhaust temperature sensor
• soot-overloaded DPF from short-trip driving
• failed regeneration due to sensor or wiring faults

How to diagnose P2455

1. Connect an OBD2 scanner, confirm P2455 is stored, and save the freeze frame data — it shows engine conditions when the fault was detected.
2. Related codes often reveal the real root cause. Also check manufacturer technical service bulletins (TSB) for your make and model — many P0xxx issues have factory fixes or software updates. Search by VIN on the manufacturer site or nhtsa.gov.
3. Visually inspect the wiring harness and connectors related to the diesel particulate filter (DPF) for damage, corrosion, chafing or poor contact.
4. With the diesel particulate filter pressure sensor "A" disconnected, measure signal voltage at the harness connector: a high reading with the component unplugged indicates a short to power in the harness; if it drops to normal, the component itself is faulty.
5. Read DPF soot load and differential pressure in live data before and after a forced regeneration.
6. Verify exhaust temperature and pressure sensor readings are plausible at idle and under load.
7. Clear the code, complete a full drive cycle including the conditions from the freeze frame, and confirm P2455 does not return.

How to fix P2455

Start with the cheapest and most common causes before replacing expensive parts:

• Replace a pressure or temperature sensor — $150–$450
• DPF replacement — $1,500–$4,000
• Forced regeneration / cleaning — $150–$400

How much does it cost to fix P2455?

Repair cost depends on which component actually failed. Typical scenarios for P2455 (parts and labor, USD, independent shop rates):

• Replace a pressure or temperature sensor: $150–$450
• DPF replacement: $1,500–$4,000
• Forced regeneration / cleaning: $150–$400

Overall, fixing P2455 usually costs between $150 and $4,000. An accurate diagnosis before buying parts saves money — the most expensive scenario is rarely the first one to check.

Can you drive with P2455?

Drive only enough to reach a service. A saturated DPF pushes the car into limp mode, and continued driving with failed regenerations dilutes engine oil with fuel — that damages the engine itself.

Related OBD2 codes

• P2400: Evaporative Emission System Leak Detection Pump Control Circuit/Open
• P2401: Evaporative Emission System Leak Detection Pump Control Circuit Low
• P2402: Evaporative Emission System Leak Detection Pump Control Circuit High
• P2403: Evaporative Emission System Leak Detection Pump Sense Circuit/Open
• P2404: Evaporative Emission System Leak Detection Pump Sense Circuit Range/Performance
• P2405: Evaporative Emission System Leak Detection Pump Sense Circuit Low