I doubt it. My scanner will hook up to the obd port and read active codes with the truck off..So got home from work today and started to investigate with my scan tool. Haven't been driving the Tahoe because of the issues and have a spare vehicle. The battery was dead so I hooked my battery charger up to it. As soon as the battery had power my scan tool turned on even though the key was off. If I'm not mistaken I shouldn't have power at the obd2 port unless the key is on. Could that be a bad ignition switch and could that explain the stumble on highway?