Case IH 17770 (F-7107-08) - ECU – Engine Control Unit (ECU): The supply module operating data that is reported on the PWM output signal is out of range

The Engine Control Unit is detecting that the pump motor inside the Diesel Exhaust Fluid (DEF) supply module is either drawing an incorrect electrical load, has an open circuit, or is being commanded to work beyond its maximum duty cycle (often due to blockages, crystallization, or internal pump failure).

• VESTRUM CVX
• Case IH Austoft 9900 / 9000 Series Sugar Cane Harvesters
• Case IH Axial-Flow Combines (260 series, 7230, 8230, 9230)
• Case IH Steiger Tractors
• Case IH Magnum Tractors

1. 1

   Wait for the Purge Cycle: Before performing any electrical checks, turn the ignition off and wait at least 2 minutes before disconnecting the battery or any harnesses.

2. 2

   Wiring and Connector Inspection: Check the wiring harness between the ECU and the DEF/AdBlue supply module. Look for open circuits, chafed wires, or shorts to ground/battery on the PWM signal line.

3. 3

   Fluid Quality Check: Ensure the DEF/Arla 32 fluid is clean and free of contamination. Contaminated fluid or crystallized urea can cause the pump motor to bind.

4. 4

   Filter Inspection: Check the DEF suction circuit filter and the main supply module filter for blockages.

1. 1

   Power Down

   Turn off the machine and observe the mandatory 2-minute wait time for the DEF purge cycle to complete. Disconnect the battery.

2. 2

   Harness Repair

   If the diagnostic checks revealed an open load or short in the wiring harness between the ECU and the DEF pump, repair or replace the affected harness section.

3. 3

   Replace the DEF Supply Module

   If the wiring is intact and the filters are clean, the internal pump motor of the DEF supply module has failed. Disconnect the DEF lines (suction, pressure, and backflow) from the module. Disconnect the electrical connector. Unbolt the DEF supply module from its mounting bracket and remove it. Install the new DEF supply module, reconnect the fluid lines, and plug in the electrical connector.

4. 4

   Reassembly and Testing

   Reconnect the battery. Turn the ignition on and use a diagnostic tool to clear the 17770 (F-7107-08) fault code. Run an engine aftertreatment test to verify that the DEF pump primes and builds pressure correctly without throwing the code.