Case IH 3426 – Engine Control Unit (ECU): Diesel Particulate Filter (DPF): Level 1 of Particulate Filter Overloaded

The system has detected that the soot accumulation inside the Diesel Particulate Filter has exceeded the normal threshold for passive regeneration, causing an exhaust restriction.

• Farmall
• Puma
• Magnum
• Steiger
• Skid Steer / Compact Track Loaders (SSL and CTL)
• Austoft Sugar Cane Harvesters
• Combines

1. 1

   Check for related fault codes such as 3427 (Flow resistance low), 3428 (Pressure sensor plausibility error), or 3429 (Pressure sensor hose line plausibility error)

2. 2

   Inspect the differential pressure sensor hoselines for melting, cracking, blockages, or leaks

3. 3

   Verify the DPF Delta/Differential Pressure Sensor is functioning and its electrical connector is secure

4. 4

   Use the Case IH Electronic Service Tool (EST) to check the actual calculated soot load versus the measured soot load

1. 1

   Visual Inspection

   Inspect the exhaust system, specifically the hoses running from the DPF housing to the differential pressure sensor. Replace any damaged hoses.

2. 2

   Perform a Parked Regeneration

   If the hoses and sensor are intact, the DPF is legitimately overloaded (Level 1). Initiate a manual/parked DPF regeneration using the operator display or the EST diagnostic tool to burn off the accumulated soot.

3. 3

   Sensor Replacement

   If the regeneration fails to initiate or the pressure readings remain implausible, replace the DPF Differential Pressure Sensor.

4. 4

   DPF Removal/Cleaning

   If the sensor is functioning correctly but the filter remains restricted (or if the code escalates to a higher severity level), the DPF must be removed. It will either need to be sent to a specialized facility for professional ash cleaning or replaced entirely.

5. 5

   System Reset

   After replacing the sensor or the DPF, use the EST to reset the DPF soot accumulator values in the Engine ECU and clear the fault codes.