So I took my 2016 SR5 4WD in for an oil change and a day after driving it home, suddenly I'm seeing the check engine light, 4LO is blinking, and the Trak Off light is illuminated.

I'm not sure it is the dealer's fault or anything untoward is happening.

Shifter is stiff.

I live in Wisconsin and about one block from a large river watershed and it fogs up a lot an night and then it freezes on your vehicle. I think my range sensor is corroded probably.

I'm guessing I have a similar issue to those described here.

So I took it to auto parts store for the sensor and P0705 pops up.

Guy mentions it may just need a new battery. To see if that is what it was, I disconnected the battery and kept if off for a few minutes. All lights were off upon ignition after re-hooking battery up. Drove it around and now only the 4LO light is on and blinking. Re-disconnect battery for 10 minutes or so, all codes and blinking lights off, shifting better.

Though I think I should probably swap the sensor discussed here. Aftermarket they appear to be generally under $100.

My question is, where on the transmission is it located? Do I need to get under the truck and take off any skid plates?

Unable to located a video for 4Runners on Youtube to do it.

If someone could kind of give me a general direction, that would be helpful. Will I need to remove skid plates, what tools I might need though it sounds like it is mostly just some elbow grease and grit to get the part off of the transmission housing.

I did find this video and it appears he is working under the vehicle since light is coming from above in the engine. https://www.youtube.com/watch?v=IeUNtUkLBwM

Thanks in advance.