PATS did not recognize key then mileage and MPG info was dashed out?

So, you are sure it's not the PCM? Also, why are only some of the fuses in my engine compartment getting power when the key is in the on position?

Hey Ken, sorry this took me so long. Life, am I right? Anyway, I got a scanner, and it would not communicate at all. Tried it on another flex and it worked fine, so it wasn't the scanner. Started the process of checking all of the fuses, both passenger and engine compartment. They were fine. Checked the relays for PCM, again fine. Removed windshield cowl and wiper arms cleaned out behind the firewall and the PCM area. Reseated PCM connections. Bought a brand new battery. Still no communication with scanner. All dash lights still illuminated, and rear lift gate will not open. It just gives a beep when I tried. Seemed like zero communication with PCM or computer brains. I was furious. So I discharged all current by touching the positive and negative battery cables. Then I let it sit. Bought a new odb2 reader and tried it out yesterday. It worked fine, but no codes. Tried the old one again, and it works fine now, but again, no codes. Drove it around the block, and no communication issues or dash lights popped on. Any advice on what it is/was? What I should do now? What I could do to replicate the problem for testing? And also it now has a lurching and revving when going into 4th or 5th gear (if there is a 5th). Any advice on that? And most importantly, my apologies again for the time it's taken me to get back to you, and a big that is for the help so far. Hit me back when you get a chance.

Hey Ken,

Thanks again so much for the help! I really appreciate it. Unfortunately, it happened again. No communication with ODB2 scanner, dashes for fuel level, all warning lights illuminated, and sometimes the odometer reads all dashes as well. Sometimes the odometer reads correctly. I've done the system reboot/power cycle multiple times, in multiple ways, and it's still nothing. Should I replace the PCM, or is there anything else it could be? For example, bad ground/wiring issue, bad relay, etc. I have to ask, although I'm sure I know the answer, but this couldn't just be an issue with the chip key, or the key reader? I tested the reader on another car, and it worked fine, so I figured it's not the culprit, but I just thought I'd cover my bases. Could this also explain that lurching and revving between the higher gears as I asked before, or is that a different issue all together? Sorry to keep bothering you about this, but I really appreciate it. Thanks again.

Do I need to check every single fuse, or are there any particular fuses that could be causing this? I already ran through the fuses and all interior fuses were good, some fuses in the engine compartment didn't seem to have power even with the key in the on position. Also, do you know how I can locate the ground wires for the PCM, as I have heard that can be an issue and prone to corroding?

Tried the scan, but no communication with car while this is happening, there was a time when the car communicated properly, and the scan worked but no codes were returned. Is there a way to check the cluster without shelling out for a new one?

Thanks a bunch my guy! I started tracing the grounds but it started raining so I didn't finish yet, but I thought I'd send you a couple pictures of some issues I'm not sure if I mentioned to ask if you thought this would be instrument cluster, or PCM, or some wiring issue. The first picture is of the clock on the nav panel, it will not set or allow me to set it through settings menu. The second is the error that I get when I go to the navigation menu. The third is the ODO when I turn the key to the run position without cranking, and the forth is what it shows after I try to crank it. Pats does not recognize the key in either case. The final shot is of the fuel level either in the run position or after a failed crank. With the software error and the clock thing do you think it could still be the instrument cluster, or more likely PCM? Or could it be wiring, or something else? Thanks again sir, I really appreciate all your help, and I'm sorry I keep bugging you. Also thanks for the wiring diagram, I think I found the ground for the PCM. Just let me know what you think when you have a chance.

Also, and I'm sorry to bug Ken, but do I need to have the instrument cluster programmed if I get a new one?

Thanks sir. Did you have a chance to look at my previous question and pictures?

This is the scanner I have. It says it's compatible with odb2 and can.
OBD2 Scanner Ease Setup Plug-Play: Clear Reset Engine Error Code Professional Code Reader Diagnostic Scan Tools with Freeze Frame/I/M Readiness for All Cars Since 1996 & Newer -LK11 There is no communication with the scanner when this issue is happening. It's like it's not even hooked up. I did get it to work the one time my car actually started and no fault codes were returned. Does that help? Thanks again Ken.

So it should be hot even with the car off, correct?