Measure your resistance. With the controller off, should have about 55 ohms across PSC/NSC with FD only, about 38 ohms with front and rear doors. How did you verify that your boards & FAST are good? You may have a bad TC.

Your other boards may be good but tool communication could be bad. Unplug Communications to Selector Board and Door Board and see if you can talk to CLC. Obviously turn power off and unplug then reboot CLC. Hope you checked power supply in car panel.

I hooked up my fast tool to car station ..I had no response from device I unplugged all connections to CLC besides the top connector and still had no response from device. I replaced CLC and selector board and still have no response from device. I did power off and reboot each time I unplugged connectors. I hooked up service tool to nearby dmc to make sure service tool is good. Car runs on inspection. What is the TC ? Traveling cable ? This all happened after piston seals where replaced

85. ohms across PSC and NSC. Power supply is good

Does PSC or NSC read to ground?
Have you tried to plug in from the door board or selector in case the plug in the COP is bad?
Check the Transorbs from PSC to NSC on the terminal strip. They should read like a forward biased diode in both directions or you can just disconnect them.
A DMC will run on Inspect without a CLC.
And your Watchdog LED on the CLC is on right?

Yes I have plugged in all ports. Toc machine room and Car panel . I read between psc and nsc. Watchdog led is steady red on clc. Selector board and door board lights are on also. Does anyone have power supply part number

85 ohms across PSC/NSC is bad. Should be around 55 or 38 ohms depending on configuration. Travel Cable (TC) may be bad. Try other suggestions that other mechanics are providing on this post, but if all else fails, if you have spare wires in TC, swap out PSC & NSC.

Its front door openings only. I. do have spares. But they are shielded. Not sure if have spares like that in tc Should I disconnect Psc and nsc in machine room and car station panel and check continuity. ?

Do they read to ground?

I will be back early tomorrow morning to see if they read to ground.

55 ohms between psc and nsc. And they are not grounded out.

Well 55 ohms sounds good with front doors only. You can measure PSC/NSC resistance to ground. With all boards and FAST disconnected, should measure 1Mohm or greater when measuring each line to ground. Also with everything disconnected, measuring across PSC to NSC the cable resistance should be about 150 ohms. If all that is good, then you still may have a board or voltage issue. You can measure the 5VDC on the CLC board on the top left corner of the board across D72. Also, you don't have old & new boards mixed? Either they're all green or all blue?

What type of FAST tool are you using?

I got communication after hooking all original boards and software back up. Now I’m trying to do learn run and getting a 10 fault on selector. Pulse count indicates out of door zone Possible my sensor board behind selector board is bad?