[991.1le]

Originally Posted by Vtor_ZL1

Sure it's not just dead or near dead battery ?

Yeah tried a couple different know good batteries with the same result.

Originally Posted by ctrlz

A couple of links which may help. There is a note about one of the sensors shorting to ground and causing all the other modules which rely on a 5V reference to go "off-line."
https://www.underhoodservice.com/ecm...cation-issues/
https://rustyautos.com/obd-wont-connect-to-ecu/

Thanks for the links! I’m thinking it’s gotta be something along those lines. Right now I have it narrowed down to all devices on the high speed GMLAN. All of the modules that communicate on the low speed network are talking just fine.