Not trying to teach you to suck eggs but you have done all this with a fully charged battery, even a small drop in voltage will upset things....?

And have you checked all the ground points you can find....?

Just a couple of free things to check....  Pete

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2014 L405 Autobiography SDV8 4.4 Loire Blue Ebony interior
2011 L322 Vogue SE 4.4 TDV8 Baltic Blue. Parchment over Navy Interior. Sold
2012 L322 Autobiography 5.0 Supercharged Ipanema Sand, Jet Interior. Sold
2002 L322 Vogue 4.4 V8 Epson Green, Ivory over Aspen Interior (Fatty Offroader) Sold
-Click for Project Fatty off roader-

btbtbtbt318 wrote:

I have picked up a little oscilloscope for some more deep diving into the CANBUS operation, and what I think I've learned is that the bus reading short circuit to itself/ground when the system is "awake" is normal when just checking with a multimeter?

Checking the bus with the oscilloscope is telling me that it is at least functioning somewhat as expected, with CAN HI and CAN LO showing opposing signals centred around 2.5 volts. The signal seems very busy/messy but that might be a limitation of the cheap scope I'm using. Looks like this: