Fan engages under load & engine shut down

Hello, I'm hoping for some help here. I have a 2010 International with an isx 500. The engine is tagged as a 2008, no DEF. I'm having a problem with my fan clutch coming on at higher rpm's while accelerating or pulling a hill under full power (engine temp is normal during occurrance) then the engine suddenly shuts off. Other times the fan clutch will engage & disengage constantly until the shut down finally happens after a random amount of occurrances. I've replaced the fuel shutoff solenoid to no avail. My engine to ecm wiring harness has been replaced. Same problem occurs. I had the circuit traced to the ecm pin & voltage tested at 10 volts on the ecm pin for the fan clutch. I have an Fcar code scanner & it only shows one code.
SPN 647 Engine fan clutch output device driver
FMi 4 Voltage below normal or shorted to lower voltage.
I know sometimes the ecm may need reflashed to fix the problem but this one I'm not sure about. It's got me to where i can't haul until it's fixed. Any help is greatly appreciated as this shuts down going down the road & I'm dead in the water coasting until I can restart the truck.

 

Ok, thank you for your reply. I figured that may need to happen.