06 dodge diesel and python 1401

Got everything installed and it works great using Virtual Tach.

I read that VT may not be the best for a diesel, and the CHALL I used provides the Tach signal, so I switched the unit to Tach mode.

It starts just fine, but as soon as the motor automatically starts to idle up in cold weather, the unit shuts down.

I have not done a diagnostic, but assume it is over-rev that is shutting it down.

Anyway to program it to not shut down, or am I better off just leaving it on Virtual Tach? Don't want to use the pure voltage sense either, as the truck continues to use a grid heater that pulls the voltage to 12 or less for 10-20 seconds at a time until warm.