Case IH 17640 (F-3251-11) - ECU – Engine Control Unit (Engine ECU): Differential pressure sensor: Digital Signal Processor (DSP) fault

The sensor that monitors the exhaust pressure difference across the Diesel Particulate Filter (DPF) has suffered an internal electronic failure within its digital signal processor.

• VESTRUM CVX
• Austoft 9900 Sugarcane Harvester
• equipment utilizing FPT engines with exhaust aftertreatment systems (DPF/SCR)
• machines utilizing the MTA CCM & APH Stage V MR on-board diagnostics system

1. 1

   Inspect the electrical connector at the DPF differential pressure sensor for moisture, corrosion, or pushed-out pins.

2. 2

   Check the wiring harness leading to the sensor for chafing, shorts, or breaks.

3. 3

   Verify that the sensor is receiving the correct reference voltage and ground from the Engine ECU.

4. 4

   Inspect the physical pressure hoses/tubes connecting the sensor to the DPF. Ensure they are not melted, cracked, or clogged with soot, which can sometimes cause erratic sensor readings.

5. 5

   If the wiring and hoses are in good condition, the internal DSP fault confirms the sensor must be replaced.

1. 1

   Turn off the engine, remove the key, and allow the exhaust system to cool completely.

2. 2

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

3. 3

   Disconnect the electrical harness connector from the sensor.

4. 4

   Carefully mark the high-pressure and low-pressure hoses to ensure they are not swapped during reassembly, then disconnect them from the sensor.

5. 5

   Remove the mounting bolts securing the sensor to its bracket and remove the faulty sensor.

6. 6

   Install the new differential pressure sensor and tighten the mounting bolts.

7. 7

   Reconnect the pressure hoses to their correct ports.

8. 8

   Reconnect the electrical harness connector.

9. 9

   Connect the Case IH Electronic Service Tool (EST) to the machine's diagnostic port. Clear the inactive fault codes and run the differential pressure sensor reset/adaptation routine so the ECU recognizes the new sensor's baseline values.