Case IH 3780 (F-519697-00) - ECU – Engine Control Unit (ECU): Torque limitation due to high differential pressure on particulate filter

The engine's Diesel Particulate Filter (DPF) has accumulated an excessive amount of soot or ash, causing a severe exhaust restriction. The differential pressure sensor detects that the pressure is too high, triggering an engine protection mode that actively derates the engine (limiting torque and power output).

• VESTRUM CVX
• Farmall 85A
• Farmall 95A
• Farmall 105A
• Farmall 105C
• Farmall 115A
• Farmall 115U
• Magnum
• Puma

1. 1

   Check the DPF differential pressure sensor and the metal tubes/hoses connecting it to the exhaust for blockages (soot buildup), melted hoses, or physical damage.

2. 2

   Use a diagnostic tool (such as CNH EST or Jaltest) to monitor the differential pressure sensor values with the engine running to verify if readings are erratic or incorrect.

3. 3

   Review the regeneration history, soot load values, and ash accumulation levels using diagnostic software.

4. 4

   Inspect upstream engine systems for underlying issues causing excessive soot production, such as EGR valve faults, turbocharger boost leaks, or failing fuel injectors.

1. 1

   Attempt a Forced Regeneration

   Connect your diagnostic tool and initiate a stationary 'Forced Regeneration.' If the restriction is purely soot, this process will burn it off and lower the differential pressure.

2. 2

   Remove the DPF

   If regeneration fails or ash is high, remove the tractor hood, air intake components, and surrounding heat shields. Disconnect the exhaust gas temperature sensors and the differential pressure sensor lines from the DPF housing. Mark the orientation of the DPF sections, unbolt the exhaust clamps, and carefully remove the DPF unit.

3. 3

   Clean or Replace the DPF

   Send the DPF to a certified facility for pneumatic/thermal ash cleaning, or replace it with a new/reman OEM unit.

4. 4

   Reinstall the DPF

   Reinstall the DPF in the reverse order, ensuring proper orientation. Torque all exhaust V-band clamps to OEM specifications to prevent exhaust leaks.

5. 5

   Reset the ECU

   Use a diagnostic tool to tell the Engine ECU that a new or cleaned DPF has been installed. Reset the soot/ash accumulators to zero and clear the 3780 fault code.