Hey all, I'm starting this post because i have been trying to find the source of my p1694 code for about a week. First the background information.

Friday 4/10/2020
I finished a fresh rebuild stroker. Around 8PM I am able to start my jeep first few cranks and proceed to do ~20 minutes of varied RPM for cam break in. After this i change the oil and button up one or two minor leaks before going for initial test drive around 9PM. Pull out of my driveway with all systems a go oil pressure great, voltage great, And coolant temps normal. I drove about 10 minutes before i lost power. Loss of power included engine shutting down and a NO BUS message on the dash accompanied by a CEL. I coast a few hundred yards managing to get it started about 3 more times before she wont start again and i was in a decent spot to wait for a tow home. tow the Jeep home and park her in the driveway overnight.

Saturday 4/11/2020
I begin diagnosis, first give it a crank and notice fuel pump is working but no visible CEL. No start, I remember reading that when installing the flexpate it is possible to mess up the CPS so i pull it real quick and notice the tip of the sensor is mildly damaged from what looks like scuffs on the flexplate, I did the simple ohm test and it failed that no big deal just a $100 mistake.replace CPS with a new NAPA Echlin one. Crank and no start, oh crap something major is wrong. I proceeded to check wiring on the main engine wiring harness. I found a few wires that had melted on the exhaust manifold due to poor routing (I'd blame my help but i should have double checked his work) The wires that melted were both the CPS supply, CPS signal, and 2 O2 Sensor wires. They were all kind of melted together and probably shorted between all of them. I fixed these wires one at a time so there was no accidental crisscrossing using those nifty self solder heat shrink butt connectors. Crank no start.
I think now is when i first checked for codes and came across P1694 the first time I found This Thread and began following every troubleshooting step posted in that thread as well as the factory service manual trouble shooting for P1694. Every test was passing, If you want me to post voltages and resistances as we troubleshoot I'm ok running back through them as i didn't write any of these down at the time. Saturday evening i noticed i was getting infinite resistance to the TCM on the CCD Bus + & - so i started running through the wiring harness and the Factory service manual checking every module and every splice in the CCD Bus System for resistance back to the PCM. I didn't finish so i stopped for the night.

Sunday 4/12/2020
I decided I would start today by removing my entire engine wire harness and rebuild all of the wire looms and inspect for any hidden damage from the melted wires. I found one or two minor issues but nothing related to the Bus system. I checked signal voltage to all major engine sensors. Throttle position sensor, Crank position sensor, Camshaft position sensor, and i also checked for signal to the coil pack while cranking. All sensors had to appropriate supply voltage ~5v DC all sensors had good grounds with ~0 Ohms resistance and i checked the signal outputs and they were within range as far as could tell without a DRB3 or an oscilloscope. At some point during this i had pulled the harness all the way back for the TCM to verify that there was no issue and it seemed that I was just getting a bad connection with my multi meter when it was under the dash. I checked the entire length of wire and wiggled the wire all over while checking for resistance. It was getting on in the day so i called it quits for the day.

Monday/Tuesday
I went back through most of the work I had done before and i still wasn't seeing anything different. I'm at the point where I think something weird happened in the PCM during the short circuit that I can't diagnose but I don't want to just replace it if i'm missing something. The TCM is blamed in the FSM after all trouble shooting steps are followed for P1694 in the FSM on page 47 of the transmission section. It didn't make sense why the TCM would have failed in this situation to me though.

Thanks for reading all of that, I just wanted to be as informative as possible before asking for help and before I started replacing computers all ***** nilly. I appreciate any help and am more than willing to repeat any diagnostic steps to help form a baseline

 

short circuiting the sensor or injector wires connected directly to the PCM is a known way to fry it, so as you have identified, after extensive troubleshooting (and finding that situation), replacing the PCM is stated as the next step

 

Ok thanks. I'm hoping I can find one locally and test it out. I'll be sure to post back for any future readers.

 

So I was a bit delayed on my reply. But I got it figured out and she's running good now! So after all of my troubleshooting I replaced the PCM with a good junkyard one but this didn't fix the issue. It ended up being a bad crank sensor even though it seemed to be testing out just fine. I realized I must have smoked it when I replaced it before fixing the short in my harness. I also ended up replacing the cam sensor. First I replaced it with a Napa premium sensor, which immediately threw a code. I bought an OEM sensor and that code cleared.
Just to repeat what everyone else says, ALWAYS CHECK YOUR CRANK SENSOR, and only use OEM sensors. Period no questions asked, I learned my lesson the hard way.