P2456 Fault Code

Diesel Particulate Filter Differential Pressure Sensor Circuit Intermittent/Erratic

• What does that mean?
• Symptoms
• Causes
• Solutions

The P2456 fault code indicates an issue with the Diesel Particulate Filter (DPF) Differential Pressure Sensor Circuit. This sensor monitors the pressure difference across the DPF to ensure it is functioning optimally. An intermittent or erratic signal may suggest that the sensor is malfunctioning or that there is a wiring issue affecting the signal transmission.

What are the symptoms of the P2456 code?

When the P2456 code is triggered, you might experience:

• Illuminated check engine light on the dashboard
• Poor engine performance or reduced power
• Increased fuel consumption as the engine struggles with emissions regulation
• Unusual exhaust smoke or odors due to improper DPF operation.
• Possible limp mode activation to prevent engine damage.

What causes the P2456 code?

Several potential causes can lead to the P2456 code:

• Faulty DPF differential pressure sensor
• Damaged or corroded wiring or connectors in the sensor circuit
• A blocked or clogged Diesel Particulate Filter
• Exhaust system leaks that affect pressure readings
• Engine performance issues that impact emissions control.

How to fix P2456?

To resolve the P2456 fault code:

• Start by using an OBD-II scanner to confirm the code and check for additional codes that might provide more context.
• Inspect the DPF differential pressure sensor and its wiring for visible damage or corrosion.
• Replace the sensor if it is determined to be faulty.
• Check for any blockage in the DPF; if clogged, a professional cleaning or replacement may be necessary.
• Ensure all exhaust connections are tight and free from leaks before clearing the code.