Case IH 17642 (F-3251-12) - ECU – Engine Control Unit (ECU): Differential pressure sensor: sensor reports an internal fault.

The engine's Engine Control Unit (ECU) has detected an internal failure or implausible signal from the Diesel Particulate Filter (DPF) Delta/Differential Pressure Sensor. This sensor measures the exhaust pressure before and after the DPF to calculate soot accumulation. An internal fault indicates the sensor itself is failing to process or transmit the correct voltage signal, rather than just detecting a clogged filter.

• VESTRUM CVX
• Farmall 40
• Farmall 45
• Farmall 50
• Farmall 105C
• Farmall 115C
• Steiger
• Puma

1. 1

   Check the wiring harness leading to the DPF differential pressure sensor for continuity, high resistance, or short circuits.

2. 2

   Verify that the sensor is receiving the correct reference voltage (battery defects or alternator issues can sometimes trigger sensor faults during cold starts).

3. 3

   Check the physical mounting of the sensor and inspect the two pressure hoses connecting the sensor to the exhaust pipe. Ensure they are correctly installed, not swapped, not melted, and free of blockages or leaks.

1. 1

   Power Down

   Turn off the machine and disconnect the battery to prevent electrical spikes.

2. 2

   Locate the Sensor

   Locate the DPF differential pressure sensor, typically mounted on a bracket near the DPF/exhaust aftertreatment assembly.

3. 3

   Disconnect

   Unplug the 3-pin electrical connector from the sensor.

4. 4

   Remove Hoses

   Carefully remove the high-pressure and low-pressure hoses from the bottom of the sensor. (Note their orientation so they are not reversed during reinstallation).

5. 5

   Dismount

   Unbolt the sensor from its mounting bracket.

6. 6

   Replace

   Install the new OEM differential pressure sensor.

7. 7

   Reassemble

   Reconnect the pressure hoses securely and plug in the electrical connector.

8. 8

   Clear Codes

   Reconnect the battery, turn the key to the ON position, and use a diagnostic tool (like the CNH Electronic Service Tool) to clear the 17642 (F-3251-12) fault code. A manual DPF regeneration may be required to recalibrate the system.