Case IH 3163 (DTC 8633) - ECU – Engine ECU (ECU A-095 / CCU / UCM): Fan clutch solenoid ECU driver over temperature failure

The electronic driver circuit inside the control module that provides power/ground to the engine cooling fan clutch solenoid has exceeded its safe operating temperature. This is typically caused by excessive current draw in the circuit, which creates excess heat.

• MAXXUM T4E
• 240 Series Axial-Flow Combines
• Magnum Tractors
• Puma Tractors

1. 1

   Check that the battery power supply has not been connected to an external power supply (such as a high-amp jump starter)

2. 2

   Visually inspect the relevant harnesses and connectors for damage, bent or dislocated pins, corroded terminals, or broken wires

3. 3

   With the engine running, unplug the fan connector (X-811) to check the fan clutch for proper default operation

4. 4

   Test the machine's charging system to ensure it is not overcharging and sending excessive voltage to the ECU

5. 5

   Check the ECU A-095 for the appropriate software version if the fault is intermittent

1. 1

   Clear and Retest

   Disconnect any external battery chargers. Clear the active fault codes. If the fault does not return, return the machine to service.

2. 2

   Inspect Wiring

   Trace the wiring harness from the ECU to the fan clutch solenoid. Look for rubbed-through insulation causing a short to ground or short to power. Repair or replace any damaged wiring or connector pins.

3. 3

   Test the Solenoid

   Test the resistance of the fan clutch solenoid. If the solenoid coil is internally shorted (drawing too much current and overheating the ECU driver), remove and replace the fan clutch solenoid valve or the complete viscous fan clutch assembly.

4. 4

   Re-flash the ECU

   If the wiring and solenoid test good, check the ECU A-095 software and re-flash it if necessary.

5. 5

   Replace the ECU

   If the fault persists after a software re-flash and all external components/wiring are verified to be in good working order, the Central Control Unit (CCU) / Universal Control Module (UCM) has a permanently damaged driver and must be replaced.