Code P1604 -- Strangest Code Ever

I was playing with a new Innova 5610 RS scanner. It has "enhanced mode" for various mfgs. to include Toyota. Generic OBD2 stuff, ABS, SRS, etc - all clear.
Get into enhanced mode and I get the P1604. On a few occasions, the truck has burped during startup, but that was more than likely me letting go of the key a hair too soon.
I cleared the code with the scanner. Will check for this code again down the road.
Truck always starts up fine, runs great.

 

I have '14 Tacoma automatic and since September, I have had my truck not start when I turned the key. Nothing, zip. So I get under the hood and rattle the wires and fuses in the fuse box, get in and it starts up.
Three weeks ago the same thing and I put on my OBD2 and no codes except misc misfire P0300. I replaced a relay in the fuse box.
Then today the same thing and I put on the OBD2 and the P1604 comes up. In between all of this and before the truck has been running well.

 

Interesting code P1604!! I had that and P1603, P1605, P0300, P0125, P144D, P2714, U0124 with ABS and Traction control and a airbag light without a code.
Now Hear this! Likely an easy repair!

I am a bit of an odd thing... a professional mechanic of some years past and a retired military physician. I have a 2017 Tacoma... and it stops running.. spins, no run. Changed out the C/OP relay for the second time, last 23 Mar... had starting issues. Sometimes start and go, and sometime.... no. Changed the relay, only aftermarket, and again... wife was over an hour away, stranded... Got on video stream with her took her to the fuse relay box and tapped on that relay.... it ran!!! did so for nearly a week... and died again... tapping.. and it will start.. and chug to a death.... looked online for about 2 days... was hearing that the dealer on another case could not figure it out... so kept at it. Now it would start and run, IF the C/OPN relay is tapped but still with a Christmas tree of lights, but no CEL..

Finally found it!!! Another relay with greater resistance, just a bit, when load leads tested at 200 ohms. replaced that relay, not sure which one... tested all of them and replaced as needed. AND started and no lights!!