Case IH 19796 – Engine Control Module (ECM) / Dosing Control Unit (DCU): SCR Inducement: Warning, triggered by DEF/AdBlue Consumption fault

The system has detected that the amount of Diesel Exhaust Fluid (DEF / AdBlue) being consumed by the Selective Catalytic Reduction (SCR) system is outside the expected parameters (typically too low) relative to the engine's fuel consumption and load. Because the system cannot properly reduce NOx emissions without the correct amount of DEF, the computer triggers an "SCR Inducement" warning. If left unaddressed, this warning will escalate into a hard inducement, resulting in severe engine derate (torque reduction) and eventually forcing the machine into "creep mode".

• Tier 4b
• Steiger
• Magnum
• Puma
• Optum
• Maxxum
• Axial-Flow 7230
• Axial-Flow 8230
• Axial-Flow 9230
• N-Series Loader Backhoes
• Excavators

1. 1

   Check DEF System Pressure using the Pro700 display or CNH EST (normal is 130-150 psi)

2. 2

   Inspect the DEF pre-filter for clogs causing pressure drops

3. 3

   Check the DEF dosing injector and pump for white, crystallized DEF buildup

4. 4

   Inspect the Coolant Control Valve (CCV) to ensure it is not stuck open and boiling the DEF

5. 5

   Visually inspect all DEF lines for leaks or pinched hoses

1. 1

   Clean the DEF Filter

   Disassemble the stainless steel inline DEF filter. Clean it thoroughly using only warm, deionized water to dissolve any crystallized urea. Reinstall the filter and check if system pressure returns to the 130-150 psi range.

2. 2

   Clean the Dosing Injector

   If the filter was clean but consumption is still low, remove the DEF dosing injector from the exhaust pipe. Soak the nozzle in warm deionized water to melt away crystallization. Do not use harsh chemicals or wire brushes.

3. 3

   Replace the DEF Pump/Module

   If the lines are clear, the filter is clean, and the system still fails to build adequate pressure (or the pump motor has failed), the DEF supply pump module must be replaced.

4. 4

   Replace the Coolant Control Valve

   If you found the DEF tank was overheating due to a stuck-open CCV, replace the heater valve to prevent the new DEF from degrading.

5. 5

   Reset the System

   Once repairs are made, the SCR system may need to be reset. On some Tier 4B machines, the system will clear the fault itself once it detects proper pressure. Otherwise, a technician must use the CNH EST laptop tool to clear the inducement timers and perform a forced SCR dosing test to verify the repair.