Fan Control Circuit engine shutoff

[snailexpress]

(11-05-2020 )INTERPRO Wrote:  Hopefully i can find the problem tonight. If i end up replacing the ECM, what would be the correct procedure to back it up and flash the new ecm with the @m*m^2 tune? Even if the ECM is not the problem i would like to have the ability to have a way to back it up or have a spare ECM. Both of my brothers are truck drivers with no electrical and computer experience.

(11-05-2020 )Signature620 Wrote:  If the trucks have the same type of accelerator and fan setup (preferably the same make and model truck) then just fit the ECM and go for a quick drive. You may run into fault codes or notice differences in driving. You are only checking that it doesn't shut down.

I would check OEM wire harness first. If wire from FAN CONTROL pin has shorts with other wires in harness or bad ground on solenoid or relay ( I don't have your truck schematic) it will create a lot of strange things.
Go to cumminsquickserve there is procedure to test. look into truck schematic for shared ground connections.