Transmisson question - won't shift into lock up

Hi Guys, Just recently my 05 Pre runner 4.0 started not going into lock up and seems to be holding shift points longer before it shifts. I was going to take it to get a scan but was wondering if there is anything obvious I should look at before I do. 165,000 miles, trans drain and refill at 103,000 miles, all stock. Thanks!

 

You could try gently tapping the brakes at highway speeds to feel if the converter is truly not functioning .
There are many reasons why this occurs and is completely computer controlled .
Transmission temp sensor , throttle position sensor , lock up solenoid , faulty brake switch , engine temp sensor . Its easier to scan rather than guess .
https://www.tacomaworld.com/threads...th-pics-for-second-gen-4-liter-trucks.289913/

 

Thank you for the reply gearcruncher. I will read that link also. Thanks!

 

Well I tried tapping the brake on the way home from work, it's not locking. I'm turning 2500 rpm's at 60 mph, I think it should be lower then that. I'm taking it to Toyota in a couple days.

 

Toyota dealership may be a great place to check for codes but they dont do much for transmission work .
Have you considered an aftermarket reputable transmission shop in your area ?

 

I currently don't know of one. I'll do a little research on it then see what the dealer says.

 

Well the dealer said everything is fine, no codes. I forgot to mention in my original post this issue starts after I drive the truck for awhile (1/2 hour or so). I don't think they drove it that long. It still was acting up on my way home today. Time to find a tranny shop.

 

Even a AAmco would know more then Toyota Shop jockeys.