2006 Tacoma V6-4.0 Transmission not engaging 4th Gear..Help

Hello all, I am having an issue with my 2006 V6-4.0 Pre-runner with 194k. Recently I had a check engine like come on and now its gone, However, I now noticed that I am unable to shift into 4th Gear. I have never changed the transmission oil on it (bad on my part), what do you guys think I can do to resolve this issue.

I am think of taking the truck to Autozone to see if there are any codes that say something about what is happening

1. Add Toyota AT fluid and check overflow drain to make sure its at the correct level.
2. Perform a drain and fill on the transmission with Toyota AF Oil.

 

Lots of information out there that claims a transmission fluid change with the amount of miles you have on your truck can cause more harm than good. Look it up and take a read, then make up your mind as to what to do.

 

@Tacologist You are correct that's why I am consulting with subject matter experts like yourself. I mean all the other gears, 1-3 are shifting well, just not going into 4th.

I guess my other option is to rebuild the transmission? Is that an option for me?

 

Your transmission has lifetime fluid. Looks like it's at the end of it's life.

Just kidding, I would do the fluid drain and fill 2 or 3 times over a couple of days and pour in some Lubegard Red each time before considering rebuilding/scrapping the transmission. Maybe this will free up whatever is stuck.

 

its only a 4sp and not 5?
Sorry just googled it, the older were auto 4 speeds...and yeah, drain and refill the tranny and see what happens. make sure you MEASURE what comes out!!

 

Thanks for the advise fellas, A little update, spoke to a friend of mine who has dwelt with some transmission problems with his tundra. I was able to get odb2 reading on the taco and it came back with P2714. My friend told me that if I cleared the code it would start shifting again. So I did that and it worked. No I have figure out what to do about the code which could have been caused by manny reasons. I will inspect the truck to see if I have any leaks in the transmission hoses. and then see if the code P2714 is being cause by low fluid or some thing else. I will keep you posted.

P2714 is a diagnostic trouble code (DTC) that indicates an issue with a vehicle's transmission pressure control solenoid "D":