Case IH 19796 (DTC F99F) – Engine Control Unit (ECU): SCR Inducement: Warning, triggered by Reagent Consumption fault

The system has detected that the engine is not consuming the expected amount of Diesel Exhaust Fluid (DEF/AdBlue) relative to the engine's load and fuel consumption, triggering a driver warning and eventual derate.

• MAXXUM T4E
• Magnum
• Steiger
• Puma
• Maxxum
• Optum
• Farmall
• Axial-Flow 5140
• Axial-Flow 6150
• Axial-Flow 7150
• Axial-Flow 8230
• Axial-Flow 9230
• Patriot series
• Titan series

1. 1

   Connect the CNH Electronic Service Tool (EST) and check the failure memory for other active root cause faults (e.g., pump control errors, pressure relief valve faults, or temperature sensor faults)

2. 2

   Inspect DEF level and quality — ensure the tank is full and use a refractometer to verify 32.5% urea concentration

3. 3

   Perform a visual leak inspection on the DEF suction lines, pressure lines, and backflow lines. Look for leaks, kinks, or a cracked suction tube in the tank that could draw air

4. 4

   Check the backflow line and connector (throttle) to ensure they are not blocked, frozen, or damaged

5. 5

   Remove the DEF injector (doser) from the exhaust stream and inspect for severe crystallization buildup blocking the nozzle

6. 6

   Use the diagnostic tool to run a DEF pressure build test and a dosing quantity test to isolate whether the pump is failing to build pressure or the injector is failing to spray

1. 1

   Resolve Fluid/Filter Issues

   If the DEF is contaminated, drain the tank, flush the system with distilled water, and replace the DEF main filter.

2. 2

   Clean or Replace the DEF Injector

   If the dosing test fails and the injector is caked in white urea crystals, clean the tip with warm distilled water. If it is electrically failed or physically damaged, replace the DEF doser injector.

3. 3

   Replace the DEF Pump (Supply Module)

   If the system cannot build or maintain the required 9 bar (130 psi) of pressure, and no line leaks are found, the DEF pump has likely failed internally and must be replaced.

4. 4

   Clear Inducement Lock

   Once the physical repair is complete, clear the fault codes using the CNH EST. Because this is an inducement code, you must run the system's 'Validation Mode' or perform a full power restart / drive cycle to prove to the ECU that the consumption fault is fixed.