I assume the DRB3 is a dealer diagnostic tool. What do you think the odds are of a Jeep dealer having this tool as it applies to anXJ
Any Chrysler, Dodge, Jeep dealer should still have one if not something better, plugs into OBD port, hopefully you have one, with proper cartridge it should support all models, the beauty part is you can select system, cruise, antilock, passive restraint, trans, hvac etc. and then monitor inputs outputs to possibly isolate problem, it is best scan tool I ever used. Being you have MJ with newer equipment I'm sure any tech would like to help maybe during lunch as it should not take too long being problem seems to be constant