These are the last two issues I had been delaying in addressing. Tested at the rear hatch and nothing wrong back there so I figured it's in the harness. I already replaced all the temperature sensors. The ones in the dash, ones on the front bumper, and up in the headliner with no success.
While going through the engine the past couple weeks, I use the 2 gauge cable to put an extra ground on the block straight to the battery, utilizing the top posts that weren't being used on my battery it also has the side posts. I also went from that top post down to the front frame rail with the 2 gauge wire. Just wanted to make sure I had a hundred percent good ground. I was surprised to discover both the above warnings have disappeared.

 

are you missing the ground strap from the block to the firewall thats beneath the hood latch lock area that goes from the rear of the engine to the firewall on the drivers side?

 

No, it's there. Cleaned the connection several weeks ago and reinstalled.....mmmm....only other possibility was I had the battery disconnected for 3 weeks while working on the engine. But I've had it disconnected a couple times for a weekend, and never changed the ice or ajar message.

 

So taking a look at the ground point at the left front of the vehicle by the tow hook, there's one wire which is the ground for the headlights and such. Then there's a ring terminal with about a 10 gauge wire on it going into the harness. This heads directly to the PCM. Looking at the wiring diagrams there's no reference to that.... But it looks completely OEM. My battery cable should have a second lead that attaches there.. but my negative battery terminal has no such lead. Apparently in my decision to go crazy with grounding, I inadvertently recreated the way it's supposed to be wired. It appears the previous owner replaced the negative battery cable with the wrong one, missing that extra lead down to the frame rail. So I suppose that means that the frame was grounded through the connection from the block to the body, and then from one of the body grounds to the frame rail elsewhere. I can only assume that the one small wire from the body to the frame that was carrying the entire negative load, must be corroded or loose. By properly grounding the frame straight to the negative battery terminal, that little wire is not carrying that load anymore. Considering I've cleaned all the grounds along the frame rail, I must have one of the interior ones such as at the b pillar that need to be cleaned that I haven't got to yet.

The good news, the vehicle has sat for 2 days with the alarm set and it has not gone off. It's never been able to do that since I bought it last February. And the ice possible warning that would come on every time you turn the key on has now disappeared.