New Holland ENG 3787 – Engine Control Unit (Engine ECU): Diesel Particulate Filter (DPF): Signal range check flow resistance of the particulate filter - very high

The differential pressure sensor has detected that the exhaust flow resistance across the DPF has exceeded the maximum allowable threshold, meaning the filter is severely restricted by an accumulation of soot or ash (DPF Soot Load Overload).

• L225
• L230
• C232
• C238
• B95C
• B110C
• U80C
• T4.75
• T4.85
• T4.95
• T4.105
• T4.115
• T4.80F/V
• T4.90F
• T5.95
• T5.105
• T5.115
• TK4 series

1. 1

   Check soot load levels and live differential pressure readings using an OEM diagnostic service tool

2. 2

   Inspect the DPF differential pressure sensor and its connecting hoses/lines for blockages, melting, or physical damage that could cause a false high-resistance reading

3. 3

   Check for related fault codes, such as 3789 (Regeneration duration exceeds maximum allowed duration) or 3796 (DPF pressure sensor hose line error), to pinpoint if the issue is a sensor failure versus a genuinely clogged filter

4. 4

   Inspect the exhaust line for any other physical restrictions or damage

1. 1

   Attempt Forced Regeneration

   If the system allows, command a forced regeneration via the instrument cluster interface or a diagnostic service tool.

2. 2

   Remove and Clean/Replace DPF

   If the soot load is too high (Level 3 overload) and regeneration is inhibited or fails, the DPF must be removed from the machine. The DPF must be professionally cleaned to remove compacted ash/soot, or replaced entirely if damaged.

3. 3

   Reinstall Components

   Install the cleaned or new DPF assembly.

4. 4

   Reset ECU Parameters

   You must use the OEM diagnostic service tool to reset the DPF soot load parameters and self-learning values in the Engine ECU after replacement or cleaning. Failure to do this will cause the ECU to continue operating as if the filter is clogged.

5. 5

   Retest

   Run the machine and monitor the exhaust differential pressure to ensure the code does not return.