OBD-II Diagnostic Trouble Code
P2455 — Diesel Particulate Filter Differential Pressure Sensor A Circuit High
The ECM saw the DPF differential pressure sensor A signal voltage above its valid maximum. This usually comes from a signal wire shorted to the 5 V reference or to battery voltage, an open ground, or an internal sensor failure. The ECM ignores the sensor and uses modeled soot values.
Severity 3/5
Truck-relevant
Service this week
Severity
Service this week
Diesel Particulate Filter Differential Pressure Sensor A Circuit High
Code
P2455
Category
Powertrain
Subsystem
Aftertreatment
Truck-relevant
Yes
What this means for truckers
Service within a few days on a Cummins X15, Detroit DD15, PACCAR MX-13. Performance is likely degraded. Continuing to drive without service risks additional component damage.
Before you replace parts — try this first
P2455 on the Aftertreatment system is most often open sensor ground circuit — not a dead part. On commercial diesels especially, work these in order before spending money on parts:
- Confirm the symptoms. Match what your truck is doing to the Symptoms section below. If the code is set but the symptoms are not there, clear the code and re-test after a drive cycle — it may not return.
- Clean and dry the sensor connector. Water, road salt, or oil seeping into a connector is the #1 fake sensor failure. Disconnect, look for green corrosion or moisture, spray with electrical contact cleaner, dry, reseat. Many faults clear here for $0.
- Inspect the wiring harness. Trace the wire from the sensor toward the ECM — look for chafing against the engine block, melted insulation near the turbo or exhaust, or pinch points where a clamp has rubbed through.
- Test the sensor before swapping it. Most Common Causes (below) list the expected voltage or resistance range — a $20 multimeter saves a $300 sensor swap that does not fix the problem.
- Only then, replace the part. Use the OEM or a tier-1 aftermarket. Cheap sensors throw the same code in two weeks.
Symptoms
The check-engine light comes on, regen control falls back to the soot model, and a derate is possible on heavy trucks if the fault stays active. Some trucks may request regens more often.
Common causes
- CommonOpen sensor ground circuit ($80–$300)
- CommonFailed sensor ($150–$500)
- OccasionalSignal wire shorted to the 5 V reference or to battery voltage ($80–$350)
- OccasionalWater intrusion in the connector ($50–$200)
How to fix
Check the ground circuit for continuity and voltage drop at the sensor
When to use: First step
Unplug the sensor and check whether the signal still reads high; if it does, look for a short in the harness
When to use: To isolate the harness from the sensor
Clean and seal the connector, and repair the harness
When to use: When corrosion or a short is found
Replace the sensor
When to use: When the wiring is good
Affects most
No specific vehicle pattern found in our complaint database. This code can appear on any vehicle that supports OBD-II diagnostics.
Related
- → Browse all DTC trouble codes
- → Decode a VIN to check codes for your truck
- → Owner-operator maintenance guides
- → P244A — Diesel Particulate Filter Differential Pressure Too Low
- → P244B — Diesel Particulate Filter Differential Pressure Too High
- → P244C — Exhaust Gas Temperature Too Low Bank 1
- → P244D — Exhaust Gas Temperature Too High Bank 1
- → P245A — EGR Cooler Bypass Control Circuit/Open
Frequently Asked Questions
Can I drive with code P2455?
P2455 is severity 3 — plan service within a few days. Performance is likely degraded already (you may feel reduced power, harsher shifts, or slightly worse fuel economy). Continuing to drive risks additional damage to adjacent components.
How much does it cost to fix P2455 on a commercial truck?
Total repair cost ranges $50–$500 depending on the root cause. The cheapest fix is usually the first one listed below — Open sensor ground circuit — which is also the most common. On commercial trucks the cost is usually higher than passenger vehicles due to part availability and shop labor rates ($120–185/hour at most truck shops, vs $90–130 at general auto shops). DIY-capable fixes (sensors, hoses, filters) are at the low end; major component replacements (turbo actuator, high-pressure fuel pump, transmission solenoid pack) are at the high end. Always diagnose with a scan tool BEFORE replacing parts — guessing wrong on a $1,500 turbo actuator when the actual issue was a $30 boost hose is a common expensive mistake.
Will P2455 fail a DOT inspection?
Yes — P2455 is an emissions-related code, and DOT inspectors check emissions compliance. An active emissions code with a check engine light can result in an out-of-service violation under FMCSA Part 393. The truck typically can't be moved until the code is cleared. Repeated emissions violations escalate to CSA scores.
What's the difference between P2455 and related codes?
P2455 is closely related to: P244A (Diesel Particulate Filter Differential Pressure Too Low), P244B (Diesel Particulate Filter Differential Pressure Too High), P244C (Exhaust Gas Temperature Too Low Bank 1), P244D (Exhaust Gas Temperature Too High Bank 1). These codes share the same subsystem (aftertreatment) and often appear together. If you see this code, scan for the full code list — fixing the root cause usually clears multiple companion codes at once. If only P2455 is set without the companions, the issue is more isolated.
How do I prevent P2455 from coming back after a repair?
For P2455 (Diesel Particulate Filter Differential Pressure Sensor A Circuit High), prevention centers on the aftertreatment system. Run quality DEF (verify supplier — BlueDEF, PEAK, Yara Air1). Don't skip parked regens — when the dash asks for one, do it. Avoid extended idle time which fouls the DPF. Replace NOx sensors at the OEM interval (typically 400K miles).