94x4runner

My 340E automatic won't shift into overdrive. It would shift into overdrive after about 10-12 miles of highway driving so I decided to change the fluid and the filter. Took it for a drive and it seemed to fix the problem. Then it slowly started taking longer to go into overdrive and then this morning I drove to work and it did not go into overdrive at all over a 15 mile drive. Overdrive solenoid? Anybody know which one it is and if it just unbolts and you can bolt up another one? I looked this up on NAPA auto parts online and they just list a automatic transmission shift solenoid. I can get another automatic from a member here but if I can fix this one I would rather go that way. I'm sure it is the overdrive because I can hit the overdrive button and the rpm does not change. When I got it to work I could hit the overdrive button and it would show the increased rpm.

4runnerx3

There is a temp sensor on the motor that tells the tranny computer when it can go into OD. There are 2 shift solenoids, and a torque convertor lock up solenoid.

94x4runner

So what do you think I should look at first and what to look for?

Team420

First... before you tear anything apart on that tranny... try unplugging the cruise control ecu... it is under the drivers side kick panel. Worked for me....

94x4runner

Is there just one ecu in this area. Not sure what I am looking for. I'm not with the vehicle right now so I am not sure what it looks like. Also would this make it intermitent. It worked a couple of times before and after I changed the fluid and filter.

94x4runner

Pulled the connector on the cruise box and no help. There are two boxes in the kick panel area. One is an alumminum box and the other is a green colored plastic box. I unplugged both of them and no help.

I guess the next step would be to do a manual shift check with the solenoid cable disconnected? Or should I disconnect the temp plug?

4Crawler

iTrader: (3)

Shifting into OD is enabled by a temperature sender in the engine. If that sender is bad or the coolant level is low or the t-stat is too cold for the engine (or stuck open) than the engine will not appear to be warm enough for the A/T to engage OD.

zlathim

If that is the case, would it be possible to use a jumper wire to complete the circuit in order to diagnose it? If you jump the terminals and it works ok, you know you have it narrowed down to the cooling system side of things. Just a thought...

Astralplane

I was having a similar problem last winter.
Changing the t-stat fixed my problem.
On a side note, I'm still having other issues with my transmission that I'm too cheap have it looked at by a pro.
I checked for codes and had none.

94x4runner

I think I will do the manual shift test first and see if I have a transmission problem or an electrical problem.

94x4runner

Ran the manual shift test and thank god the tranny works fine. Pretty weird driving the runner manually. Should I just change both the temp sensor and thermostat or try the temp sensor first. I'm sure there is a way to test the sensor anyone have that information?

4runnerx3

You should be able to test it with an ohm meter. The FSM should give the readings for different temps.

94x4runner

I think I'll just check the thermostat and put in new coolant and see what happens. I noticed my temp stayed around the 1/4 range so it sounds like a stuck thermostat.

94x4runner

No wonder I had a problem. I bought this runner two weeks ago and can't beleive some of the things I have had to do. I pulled the thermostat and all that was there was the face the whole body was gone. I didn't find it in the block so I am guessing the previos owner or his mechanic took the body off to make it flow wide open and I think he was running straight water or hadn't had the coolant changed in forever. It was pure rust coler. Drained,flushed,replaced the thermostat and serviced with new coolant. Runs like it should and I have overdrive back. Thanks everyone for your help.

STEVE_R

i currently have the same problem now, well until later this after noon. toyota is notorius for having this problem, the selenoids or connectors can become corroded after only 40,00 mi. i bought a selenoid kit, it comes with everything you need: tranny filter, gasket (you choice of cork or silicone) selenoids with new connectors and brackets along with complete instructions.forget about going to your local auto store, they charge an arm and a leg for it, i ordered mine on-line( i'll have to do some digging to find out where i got it from) it was about $125 cheaper! if you do decide to do this on your own, keep in mind your going to want to drain the touque conv. also, no sense in half ass'n it. my father-in-law is a mechanic and has a vacuum i guess.------ nevermind, didn't read rest of the posts.sorry!