How to detect if the Cummins 24v VP44 ECM has been enabled for high idle? It not to hard to check to see if you have high idle software present. The only thing you need is a resistor that is a 39k ohm or greater up to no more than 100k ohm resistor. The other requirement is to have a cold engine. Engine coolant temperature must be below 140*F for this test to work properly. Just unplug the IAT sensor and take your resistor and fold the legs over and insert into th