Can Bus Comm Issues?

I forgot to mention
I also measured 61 Ohms at the OBDII
Thanks
Wes

Youre undoubtedly on the right track Sounds like you ve traveld down a pretty long bumpy road woth it so far but great job that said ...The clicking your hearing is most likely not the bcm it being a solid state unit I believe on this model (no relay inside) although there may
a problem there its pretty unlikely at this point
..
There is a relay or two right near it though that could be clicking i believe one is the lock relay .. can be a loose ground hence the locks acting crazy.. ..theres 2 ground points that can get loose or corroded one is way up under the dash lower left corner of the windshield near the speaker cover ? Sorta ?...and the other is down below behind the driver side kick panel just under the left foot plastic Cover id check those i believe they ground the relays and the Bcm.so they .can raise hell .with the bcm. And others also for what its worth
You had alot of codes in the list its abnormal to get that many at once especially right after resetting it as I believe you meantiined.. unless there are bad grounds hiding somewhere thats why it points to the grounding points designation points (g200 and g201 ) they usually have maybe 4 grounds going to each the most likely one would be the one by your left foot onder the plastic cover there more moisture dow there a.d it get kicked alot over the years so stuff gets loose amd corroded lucky its easiest to check though so thats a good place to start .so i compleatly agree with what you where saying about it seeming like its a ground issue..good luck hope this help at least a little.

Oh and and on the model yiu have the body ground point designation (G218) for the bcm grond wire if you want to check that ? pull of the plastic windsheild A pillar cover then pry up the vent cover i think youl see it down there at the almost down where it meets the bottom of the windshield somewhere there in the lower corner screwed to sheet metal there thats the ground for the bcm it gets corroded there lots of moisture from the windshield being righ above i guess its kind of a bad place to hide it. Anyway best of luck to you .

On that bcm ground ..They put out a bulletin that basically say its k ow to chase many phantom issues with the bcm glitches cuasi g multiple code amd flickering ..and so on ..says its due to the position and factory paint and such..say clean all surfaces with sand paper to a giod ground amd reassemble it ..it the problem was there you should be goo to go good luck

I will look for and clean ground under plastic at foot you mention. I did clean both grounds at each side under dash, cleaned ground on driver side frame and at back above spare tire. As earlier mentioned ground at battery has already been replaced.

Some more info,
I did a continuity test from ground through my multimeter to X7 pin 13 to see if my Park Position Switch was good. It kept a solid ground signal until I would lift the lever so this switch is good. I also turned on the accessory mode while keeping my meter connected and the Park Symbol stayed highlighted where before it would go off and on. I questioned if I was providing a ground with my meter? 2 other things to note for this test, when I applied the brake I would loose continuity from ground to the Park Position switch going to ground...? Unsure why this happened and when I cranked the engine the Park symbol started again going Highlighted to Un-highlighted as before.

With my meter removed from circuit.
When cranked I mentioned before but listing again, there are issues and things happening at the same time "P" Park position goes from highlighted to un-highlighted on the dash which are, Stable track light appears and disappear, The door locks go up and down, I also noticed the Daytime running lights go on and off, The switch to move the pedals in or out only works when the "P" park position is highlighted, the switch to open or close the lift gate only works when "P" is highlighted.

I did one more test, my High Speed GMLAN Serial Data 1 voltage at the OBDII as mentioned was low when in off mode.... It depends when I check if all modules are completely asleep but I believe I've measured between 1.34V on both to around 1.69V... but should see around 2.5V. I decided to disconnect X6 from the BCM and back probe pins 23 & 24. With X6 removed from the BCM I measured 2.5V. This makes me lean toward the BCM is my whole issue but I need to confirm for sure by checking grounds, like why did I loose ground from the park position switch when pressing the brake pedal?

I will do some more checks today.

Ok theres one more place ti check i forgot this is the number one spot that cuases this problem on this vehicle tell me if you checked this spot ok " there's acually two spots and given the code your getting it migh be reaking havoc on the can bus and all the moduals based on the perticular set of codes you see when there's bad grounding and the vejicle will often retreat into limp mode .
Please check these"
There are two grounding points outside in the elements underneath on the bottom of the vehicle just behind the two front wheels below the passenger seat and drivers seat areas on this vehicle its a big issue becuase every dirty wet roadscumy thing known to man clings to it down there and corrodes the ground wire eyelets youl proba bly find it all rusty on each side after digging through all the mud clinging to it cleann those as best you can and and the vehicle side too there most likely will be a big improvement becuase the codes given are indicating grounding can bus comunication and also moduals grounding problems and possibly power issues due to these grounding issues.this set of codes is super common on this vehical when the sort of one big issue with the grounding and these grounding areas we've gone over are the biggest reasons for this happening on this vehicle if you clean these really good you might solve many of these problems in one go" once youre done and its all clean earase the codes reset the ecu completly. run the car take note of what's changed ..run it fir 20 mins or so and see if any came back my guess is you won't see a whole lineup of codes anymore it will settle down and if there are any codes at all there might be one or two if you get it to the level out and calm down then youre pretty much out of the dark and if any codes appear they will be more definitive that would be great and probaby for smaller issiues easier to fix ..but for now I'd say dont worrie to much about any small stuff and just keep forging ahead with the grounding of the system you've come a long way feels like your alot closer now .Great job keep up the great work ...good lu k hope thus helps ..let me know. Thanks

Just a small side note Keep in mind alot of these issues with minor voltage changes will get back under control as this ground problem is solved. Becuase when its not properly grounding the power distrebution relays moduals and things all around the vehicle ..it gets all confused some dont turn on/off at the right times ..and it protects all the components by putting it into limp mode wich is a good thing once there's a healthy dround network again it will be safe to come back out of limp mode again and many things return to normal...best of luck to you

Also one thing that seems to be over looked alot is simple its the door jam buttons theyre important to be funtioning properly so id check those too" becuase just opening the doors wakes up the bcm activates interior lighing security moduals and enables and alot of other things around the vehicle and since there only the two for obvious reasons the drivers side is the most likely to break first since it gets way more use push in and out to see if interior lights come on without flickering or anything strange its just asimple on off switch but it can rais hell when broken on many vehicles good luck