Case IH F-518151-31 - ECU – Engine Control Unit (ECU / ECM): ECU Internal failure - Post injection efficiency failure

The engine's control system has detected that the post-injection event is failing to achieve the expected efficiency or temperature increase.

• MAGNUM AFS Connect
• 240 Series Axial-Flow Combines
• Austoft 9900 Sugarcane Harvesters
• Farmall series
• Magnum series
• Steiger series

1. 1

   Clear the fault code memory and operate the vehicle under load for a short distance to see if the error returns

2. 2

   Inspect the engine oil for fuel dilution, which indicates a failing injector or rail leakage causing poor post-injection efficiency

3. 3

   Check battery voltage, alternator output, and wiring harnesses for high resistance or defects that can trigger false ECU internal failure codes

4. 4

   Verify the plausibility of the DOC upstream and downstream temperature sensors, as well as the SCR/DPF differential pressure sensors

1. 1

   Perform a visual inspection

   Perform a visual inspection of the engine wiring harness, specifically checking the connectors at the ECU and the fuel injectors for corrosion, pushed pins, or moisture.

2. 2

   Test the exhaust aftertreatment sensors

   Test the exhaust aftertreatment sensors (temperature and pressure). Replace any sensors that are reading out of range or failing plausibility checks.

3. 3

   Check the fuel system

   Check the fuel system for proper rail pressure and ensure the injectors are functioning correctly without leaking into the crankcase.

4. 4

   Force a manual regeneration

   Force a manual regeneration (if the system allows) using a diagnostic tool to monitor exhaust temperatures and verify if post-injection is physically occurring.

5. 5

   Replace or Flash the ECU

   If all wiring, sensors, and fuel system components are verified to be in good working order, and the code immediately returns after clearing, the ECU itself has suffered an internal hardware or software failure and must be replaced or reprogrammed by a dealer.