2012 Tacoma Neutral Safety Switch Wiring Harness Problem

Replaced the NSS checked most of the wiring and seemed fine. Couldn't figure out what was wrong with it. Its has a p0705 code. Has all the symptoms for a bad NSS like PND42L doesn't light up on dash. Only R and 3 lights up. 4x4 blinks also. Decided to take to a dealer for them to look at and they first told me it was a bad NSS, but it wasn't. They ran a voltage test on the NSS wire and said there is a open circuit in the wiring harness to the junction block. They told me ill have to take the cab off to replace it. Is there another way to replace it without taking the cab off? or should I just run a jumper wire? Could it also be something else causing this issue? Also when i got the truck back my Neutral lights up now but only when i have the shifter in Drive. Before I brought it to them it would only start in N and P, but now only starts in P

 

For 1 it sounds like the switch is faulty or mis-adjusted.
How handy are you with a test light and multimeter?

 

I first replaced it with a duralast one then the dealer replaced it with an oem one. I’m decent with one. Just don’t know how much voltage or ohms require for each wire.

 

Ok you can check all the signals except the starting circuit from the switch backprobing connector PB on the junction box behind the glovebox.
Each pin should be at battery voltage with the shifter in the respective position, the rest should be at or near 0v.

Pin 5 (Green/Black) Park
Pin 6 (Red) Reverse
Pin 8 (Blue/White) Neutral
Pin 2 (Blue/Black) D & 4
Pin 1 (Yellow) 3
Pin 7 (Red/Yellow) 2 & 1

 

Okay I will try this out thanks!

 

It’s an open Circuit park and D&4 would you possibly have a full wiring diagram for that. I’m just gonna run a jumper wire

 

Are you sure it's and open wire and not just a bad or misadjusted switch?
Did you check them at the switch?
Transmission wiring attached below.

 

I haven’t tried to pull the wires to make sure they’re in good, but yes I traced the wires I best as I can it all looked good and I replaced the NSS and then also the dealer replaced one as well

 

Hi Joshua.....what did you end up doing to repair your 2012 Tacoma ?
Because I am having the same problem.....I think I have Broken Wires in my NSS harness.
Installed new oem switch and P does not illuminate on the dash and if I jiggle the harness after reaching on top of the transmission the neutral light flickers. Also truck won’t start in any position.
Your experience may help me decide which direction to go to repair my 07 Trd sport l!