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Home > Knowledge > China VI C878 Fault Code Repair Guide (Full Diesel Version)

China VI C878 Fault Code Repair Guide (Full Diesel Version)

Author:F-Diesel Date:October 11, 2025 2:38 AM Tag:[ ECU DPF signal inspection , DPF sensor wiring harness test , Diesel particulate filter sensor , DPF differential pressure sensor ]
This knowledge base introduces or describes the This guide explains the function, structure, and troubleshooting of the DPF differential pressure sensor used in diesel engines. It covers diagnostic trouble codes (DTCs), technical parameters, operating principles, wiring inspection procedures, and voltage signal thresholds to help identify DPF clogging, sensor faults, and ECU communication issues.

Table of contents

1、DPF Differential Pressure Sensor

2、Basic Information

3、Code Logic

 

1. DPF Differential Pressure Sensor

 

DTC                Description

P245264       Unreliable DPF Differential Pressure Sensor Signal

P244BF0       Excessive Deviation of the Learned Value of the Differential Pressure Sensor

P244B00       Excessive Pressure Differential Across the DPF (DPF), DPF Clogged

P226D09      The DPF is Removed or Failed

P245212       The DPF Differential Pressure Sensor Voltage Signal Exceeds the Upper Limit

P245211       The DPF Differential Pressure Sensor Voltage Signal Exceeds the Lower Limit

 

2. Basic Information

 

The Engine Control Unit (ECU) measures the differential pressure across the DPF using the DPF differential pressure sensor to calculate the accumulated carbon particulates and ash.

 

2.1 Technical Parameters

• Power Supply Voltage: 5V

• Operating Temperature: -40°C to 130°C

• Measuring Pressure Range: 0 to 100 kPa (Differential Pressure)

2.2 Operating Principle

The DPF differential pressure sensor consists of a sealed elastic silicon chip and a corresponding bridge circuit. A standard 5V voltage is applied to one end of the bridge. When pressure changes, the silicon chip deforms, the sensor resistance changes accordingly, and a 0 to 5V voltage signal is output to the engine control unit (ECU).

Wiring Harness Link and Actual Location Diagram

 

 

3. Code Logic

 

P245212: The DPF differential pressure sensor signal voltage is greater than the set threshold.

P245211: The DPF differential pressure sensor signal voltage is less than the set threshold.

DPF Differential Pressure Sensor Control Circuit Inspection

3.1. Turn the ignition switch OFF and unplug the DPF differential pressure sensor wiring harness connector.

3.2. Turn the ignition switch ON and measure the status of each pin on the DPF differential pressure sensor wiring harness connector.

3.3. Power supply line: The voltage between pin 1 and vehicle ground is normally 5V.

3.4. Ground line: The voltage between pins 1 and 2 is normally 5V.

3.5. Signal line: The voltage between pin 3 and vehicle ground is normally 5V.

Detailed Inspection: Use a multimeter to measure the resistance between pins 1, 2, and 3 of the DPF differential pressure sensor wiring harness connector and pins A21, A40, and A10 of the ECU wiring harness connector to see if it is ≤2Ω.