Case IH 19787 (DTC F49F) - ECU – Engine Control Unit (ECU): SCR Inducement: Level 1 (Torque reduction), triggered by DEF/AdBlue dosing interruption fault.

The system has detected an interruption or failure in the DEF (Diesel Exhaust Fluid) / AdBlue dosing (injection) process. Because the aftertreatment system cannot properly reduce emissions without DEF, the system triggers a "Level 1 Inducement." This is a forced engine torque reduction (derate) designed to protect the system and force compliance with emissions regulations.

• MAXXUM T4E
• 240 Series Axial-Flow Combines
• 7230
• 8230
• Magnum 250 CVT
• Farmall 115U
• Puma
• T7 Series
• Case CE Wheel Loaders
• 621G
• 721G
• 1121G

1. 1

   Verify Root Cause Codes: Look for accompanying codes (such as E-1757-03 or DTC 31E) that indicate specific electrical shorts or catalyst efficiency drops.

2. 2

   Temperature Sensor Check: Turn the key on without starting the engine (cold engine). Navigate to the info/engine screen on the monitor and check the exhaust inlet, outlet, and intake temperatures. They should all be within a few degrees of each other. If one sensor is reading wildly out of range, a bad temperature sensor is throwing the ECM off.

3. 3

   Inspect the DEF Dosing Module: Check the DEF dosing module (pump/injector) for crystallization or blockages, which is highly common if the machine has been sitting idle for long periods.

4. 4

   Check for Freezing: If operating in winter, verify that the DEF tank heater has not failed, which causes the fluid to freeze and interrupts dosing.

5. 5

   Wiring Harness Inspection: Check the DEF system wiring harness for chafing, corrosion, or 'shorted to high source' conditions, which frequently cause dosing interruptions.

1. 1

   Resolve Electrical/Sensor Faults

   If the diagnostic check revealed a faulty exhaust temperature sensor or a shorted wiring harness, replace the affected sensor or harness first.

2. 2

   Clean or Replace Dosing Components

   If the wiring and sensors are intact, the physical dosing interruption must be addressed. Inspect the DEF metering valve, mixing chamber, and ignitors. Clear the muffler of any blockages.

3. 3

   Replace the Dosing Module

   If the dosing module is internally blocked or has failed electrically, remove and replace the DEF dosing module/injector.

4. 4

   Clear Codes and Run a Regen/Load Test

   After replacing the faulty components, clear the fault codes. The engine exhaust must reach over 450°F to normalize the SCR catalyst efficiency. Run the machine under a heavy field load (or on a dyno) to bring the temperatures up. Once the system verifies that DEF is dosing correctly and NOx levels drop (from ~500 PPM to under 200 PPM), the Level 1 torque reduction will be lifted.