Case IH 3793 – Engine Control Module (ECM) / Electronic Diesel Control (EDC): Diesel particulate filter (DPF) : Conditions non plausible for DPF emergency regeneration

The engine management system is attempting to perform an emergency (forced) regeneration of the Diesel Particulate Filter to burn off accumulated soot, but the required operating conditions (such as exhaust temperatures, pressure differentials, or sensor plausibility) are not being met, preventing the regeneration cycle from executing.

• Puma 130
• Puma 145
• Puma 160
• Puma 170
• Puma 185
• Puma 200
• Puma 215
• Puma 230
• Magnum series
• Farmall tractors

1. 1

   Check for accompanying sensor codes related to the Intake Air Pressure Sensor (Codes 3794, 3795) or the DPF Differential Pressure Sensor (Codes 3796, 3797, 3798)

2. 2

   Inspect DPF Pressure Sensor hoses for blockages, melting, or leaks which can cause implausible readings

3. 3

   Check fuel delivery system for inlet/return restrictions, air ingress into the fuel supply, or poor performance of the gear supply (lift) pump

4. 4

   Verify if an ECM software update is available to resolve known frequent regeneration monitor defects

1. 1

   Read DTCs

   Connect a compatible diagnostic scan tool to the tractor and read all active and stored Diagnostic Trouble Codes (DTCs) from the EDC/ECM.

2. 2

   Inspect DPF differential pressure sensor and hoses

   Visually inspect the DPF differential pressure sensor and its connecting hoses. If the hoses are cracked, brittle, or blocked with soot, replace the hoses.

3. 3

   Monitor live data and replace sensor if necessary

   Monitor the live data for the DPF Delta Pressure Sensor and Intake Air Pressure Sensor. If the pressure sensor readings do not change under load or read out of range, replace the DPF Delta Pressure Sensor.

4. 4

   Perform fuel pressure test

   Perform a fuel pressure test to ensure the high-pressure pump and lift pump are delivering adequate fuel without air bubbles. Repair any fuel leaks or restrictions found.

5. 5

   Update ECM software

   Flash/update the ECM with the latest software calibration from Case IH to resolve any logic errors preventing emergency regeneration.

6. 6

   Clean or replace DPF filter

   If all sensors and fuel systems are functioning properly, the DPF filter itself may be face-plugged or overloaded beyond the threshold where emergency regeneration is permitted. In this case, the DPF must be removed and professionally cleaned or replaced.

7. 7

   Reset soot load and verify operation

   Once repairs are made, use the diagnostic tool to reset the DPF soot load values and command a stationary forced regeneration to verify the system operates normally.