2014 Tacoma-Trac Light- ABS Light-Tire Pressure Light-Will Not Shift Out Of Prk

Trac-ABS-Tire Pressure lights on & will not shift out of park.
2014 Tacoma 4cyl Automatic
Tow brake control for small camper mounted under dash.

Sequence of events:

TRAC LIGHT:
Came on & stayed on.
Toyota Service diagnosed & re-calibrated the module (their words) & the light went off. $$$
Trac light showed ON again after a tire rotation about 11 months later.

TIRE PRESSURE LIGHT:
Light shows on all the time. My tire pressure is OK. I've checked it many times.

WILL NOT SHIFT OUT OF PARK:
Could not shift out of park, but eventually after fiddling with the steering wheel position & applying the brakes I got it to shift. Happened twice. I researched & changed out the brake switch as that seemed the most likely culprit. I also learned about the hidden switch located on the gear shift area that can be manually depressed to signal the shifter that it's OK to shift out of park.
All OK for several months.. but recently it's happened again..the shifter will not shift out of park...so changing the brake switch was not the culprit.
I now have to depress the hidden switch every time to shift out of park.

ABS LIGHT:
ABS light is on.
The ABS light will usually go off when I manually depress the tow brake control under the dash, but the ABS light eventually comes back on. I tested to see if this was only when towing, but happens when I'm not hitched or connected to the camper.

While each problem separately could be an individual problem & failure of a dedicated part to that specific problem, with all of these things happening in a somewhat domino effect it seems to my mechanically uneducated brain it could be a failure on a 'central control sensor or ????
Looking for things I can do to troubleshoot these issues myself & determine if it's all a connected issue & ask that you please be respectful in your responses & don't just say "take it to the shop".
I know I can just start replacing parts such as tire-wheel sensors or whatever in hopes that something works.
That seems to be the way the 'shops' do it & charge you for every 'guess' but I prefer to go about it in a more informed way & if I eventually need to take it to a repair shop at least I'll be informed to lessen the chances of being taken advantage of.
Thanks in advance!

 

It would help if you can give us the ABS codes.
You’ll need a scanner to pull the codes.
My suspicion is the towing converter since the light goes off when you mess with it?

 

I can look into purchasing a scanner. But, can the ABS issue, since it happened last, be connected to the Trac Light, the Tire Pressure Light & the Gear Shift issue?

 

I suspect the TPMS light is unrelated, does it flash at first and then stay on?

Do your brake lights work?

 

It could yes.
Depending on the code, it can cause 1 or all of those lights to come on.
You don’t need to buy a scanner. Go to your local parts store and ask them to scan the truck.
Most have scanners now than can pull ABS codes. Just make sure their scanner can pull them.

 

Being the shift interlock isn't working either I'd suspect something in the brake circuit.
If your comfortable doing it the codes can be flashed out on the light using a jumper wire in the DLC.

 

Yeah, fooling with the tow converter makes the light go out.
Which the converter is connected to the brake system.

 

Yes, my brake lights work.