Case IH 3788 – Engine Control Module (ECM) / EDC: Diesel particulate filter (DPF) : Diagnostic fault check for incomplete regeneration of particulate filter

The engine attempted an active regeneration of the Diesel Particulate Filter (DPF) to burn off accumulated soot, but the process was interrupted or failed to complete successfully. As a result, the soot mass inside the filter did not decrease to the expected threshold.

• Farmall 75C
• Farmall 85C
• Farmall 105C
• Farmall 115C
• Farmall 115U
• Quantum series
• Magnum series
• 5140

1. 1

   Review operating habits for excessive idling, short trips, or low-load operations that prevent passive and active regeneration

2. 2

   Check DPF differential pressure sensor readings with a diagnostic scan tool for abnormally high pressure at idle or out-of-range voltage, which may indicate the sensor or its pressure tubes are clogged, melted, or faulty

3. 3

   Inspect the EGR valve to ensure it is not stuck open (which increases soot production)

4. 4

   Verify that the fuel dosing system is operating correctly to raise exhaust temperatures

5. 5

   Check for secondary codes related to the turbocharger, EGR, or exhaust temperature sensors

1. 1

   Perform a Forced Regeneration

   Park the machine in a safe, well-ventilated area away from combustible materials. Initiate a 'Forced' or 'Manual' parked regeneration using the in-cab DPF switch or a CNH diagnostic scan tool (EST).

2. 2

   Monitor Temperatures

   During the forced regeneration, monitor the exhaust gas temperature (EGT) sensors to ensure the system reaches the required temperature to burn off the soot.

3. 3

   Replace the Pressure Sensor

   If the forced regeneration fails to initiate or aborts due to implausible pressure readings, replace the DPF differential pressure sensor and blow out the sensor lines with compressed air to ensure they are not blocked with soot.

4. 4

   Clean or Replace the DPF

   If the DPF is severely restricted and forced regeneration is inhibited (or if the filter is saturated with non-combustible ash), the DPF must be removed from the exhaust system and sent to a specialized facility for pneumatic/thermal ash cleaning or replaced entirely.

5. 5

   Clear Codes

   Once the repair or regeneration is complete, use the diagnostic tool to reset the soot mass accumulator and clear the 3788 fault code.