If you took a look through the wiring diagrams I put in last night, I didn't show you the end of the circuit because I didn't think it applied, but on that same power feed from that fuse at the end of the circuit is the Engine Oil Pressure control valve. So, if you're having oil pressure issues this is why every single code you are getting and every single component for those codes is powered up (12v) on this one violet/light blue wire. So, it's not an oil pressure issue or a temperature issue with the vehicle. It's that this power feed is either shorted to ground or is running through a corroded connector and possibly shorting to other circuits or has a component on it that is shorted out.
Here's a little plan of attack for you: Go directly to this fuse in Diagram 2, check it for 12volts with the key On. If power is missing and/or the fuse is blown, we now know every component on that circuit, the list is on diagram 3, and you'll notice that one of those codes actually says that this will open the fuse to the Thermostat, since this is not a regular thermostat, it has a heater built in and is Pulse Width Modulated, meaning the engine ECM pulses the ground circuit to control it. Most likely there is some computer protection inside the ECM to prevent damage to it and hopefully it worked.
But with all these low voltage codes and the oxygen sensor performance codes, the oxygen sensor will not work without the heater circuit that's built-in working, it will never get up to operating temperature and that's why you got the original oxygen sensor codes.
So, this one circuit is the problem for all your codes, amazing one wire and fuse can cause so much headache. But when you are feeling better, we need to figure out why this circuit is not supplying power to these components, I would put the original thermostat back in for now. And we will start at this fuse (misc. 2 fuse 10amp) and work our way through the circuit to determine where the short to ground is and hope it didn't cook the ECM.
Glad you mentioned the oil pressure issue, I was wondering about that last night, it's the last component on the circuit.
Let us know when you're feeling better, and we'll help you figure this out without replacing any more parts for now.
Hope you get better soon.
Images (Click to enlarge)
Tuesday, November 22nd, 2022 AT 9:03 AM