Transmission shifting

Skydvvr, pretty sure that's the thermostat.

Kywoodsrider, yeah, that's the one that the parts guy gave me the number for.

Roundrocktom, I checked the cable by letting it go from the the tranmission when it was really had to get into drive. With the cable disconnected, it was a free as anything - hooked it back up to the linkage, could barely get it into drive. It's definitely not the cable in my case.
I'm betting on the NSS. My plan is to get it off and take it apart, hopefully get it cleaned up and blocked with lube.

 

Roundrocktom do you have the schematic for the neutral safety switch on the 3rd gen.?

 

We need the snow for the snowmobiles... asphalt and dirt tears the crap out of them.

 

Wow, thanks, that's very much appreciated. Looks like the only thing the switch is NOT connected to, is the muffler!
Just to confirm, the side view showing the location is for the 3rd gen. Taco?

 

Correct. I'm looking at 2021 documents.

I was a tech way back in the day (Points/Carbs). I'm older than dirt, hence still fond of documentation for any vehicles I own. Slowing down as it took me 1.5 hours to install the tailgate remote lock and my hip has been bugging me since! Maybe I should drive a 1972 Gran Torino.

 

Points/carb... 8 wires plus a coil wire, those were the days! Full disclosure, dirt was invented after my 3rd b'day.
I too miss the days you could diagnose a problem in the driveway with just a probe light and a beer.
I've got the service manual for my last Taco ('07 SR5) - looking like I might need it for this one as well.
I installed the lock in my tailgate as well. Combined with the solid folding cover, it makes a nice secure space.
Many thanks again for your help.

 

When the range sensor ( Neutral safety switch ) starts messing up , they get very stiff followed by code P0705 if you have a scanner .
Usually the illumination of what gear you are in also drops out .
Seen this question every other day on the 2nd gen forum and slowly , we are starting to see the issue popping up with 3rd gen trucks .
What do you expect when Toyota installs a printed circuit board under the truck . These things are not sealed well which means water intrusion and corrosion from continuous exposure to the elements .
As your truck gets older , look forward to other printed circuit boards under the truck doing some wonky things .
The front ADD for locking your front axle into 4x4 and back into 2 wheel drive
The transfer case shift motor used for range selection ...2 high, 4hi and 4 low
If your truck is an off road , you also have the printed circuit board for the locking diff .
If you take your truck swimming in the deep end of the pool , I highly suggest dropping a nice silicone bead around all the seals where the wiring mates with the device .
Disconnect battery , Take the key out , make sure your truck is in park .
Go under the truck and replace the range sensor .
Once replaced , verify the truck only starts in park and neutral . The transmission will have zero issues going through the detents after you replace the range sensor

 

So is the range sensor different than the Park Neutral Switch or are we talking about the same thing?
If it's different where is it located?

 

Thanks gearcruncher, I've been looking at this as a mechanical issue mimicking an electrical issue, in that it's coming and going, not becoming progressively worse. Your comment about the water intrusion has me thinking that the NSS is getting wet internally on mild, wet days and then freezing when the weather turns colder later in the day, being impossible to get into gear in the morning. It's eventually drying out with the heat of the engine, exhaust and transmission itself and shifting fairly decent after making several trips.

I was out this evening, -4C with a wind-chill of about -15C and it shifted fine, so it doesn't appear to be just a 'cold weather only' issue as I initially thought. I've never considered a connection with wet conditions preceding a cold snap, something to watch for.

Hopefully I'll get in the garage this weekend and get it out on the bench to seal it up and save $285 (+HST)!!

 

You nailed it with everything you explained above .
In my opinion , you gotta catch these issues before they occur .
Its a printed circuit board and there is 5 volts of direct current travelling through 7 different circuits inside that critter depending on which gear you are in . The circuit board burns black just like you see inside an overheated computer motherboard but then add in the corrosion factor from the water and outdoor elements .
What I am trying to say is chances are you may need to replace it .

Also check and clean the wiring pins carefully
Here is what happens when water gets into the pins at the wiring harness.
We call it green death in the transmission trade.
Water will leak into the pins and then into the switch causing some nasty issues .
The first thing you see is loss of connection and a code is triggered .That nice green light on the dash doesnt illuminate when you are in drive
All that green crap prevents the pin ( wiring ) from a proper connection .
If you catch it quickly and clean the corrosion and re-seal , you may get lucky but its a massive pain in the @ss to work on the range sensor while its in place .
That green crap doesnt clean up like new . Usually takes out the male and female portion of the pin and the wire . Believe it or not but baking soda is best for cleaning this . Rostra makes harnesses if you want to save from buying OEM. Get ready to solder and heat shrink for hours .
These are the issues that occur with printed circuit boards being placed under the truck . General motors started this mess . Toyota followed in their footsteps . Ford as well as chrysler also suffer from these issues. Funny how they last until the warranty is expired ????

 

That connector pin corrosion, "green death" as gearcruncher described it, is not unique to automotive connectors and was/is an occasional problem with aviation electrical, especially on aging aircraft. It can be prevented with a liberal application of silicone grease/dielectric grease on the connector. Packing some grease into both sides of the connector will coat the contacts and fill the voids where water could/moisture could collect. It will also lubricate the rubber seals on the "weatherproof" style connectors with rubber seals and keep them in good shape longer plus make them easier to disconnect later. It is becoming a standard practice in Aviation to do this where it's allowable and I have been doing this for years on my vehicles whenever I have connectors apart that are exposed to elements.