Can somebody please help me! I have a 94 4runner 3.0 with an automatic transmisssion. Recently, the trans has been acting up by downshifting by itself while driving around and on the freeway. Seems like it's downshifting to 2nd gear because the RPMs picks up and the engine revs. Also, seems like the trans is shifting between gears and doesn't know which gear to driven in. Could this be the throttle positioner? I had a friend who had transmission problems and he ended up changing the throttle positioner.

 

hey man, my mom's 4runner is doing the same thing! no one has been able to figure it out. let me know if you find something out.

 

Hey Guys,

My '93 was doing the same thing. I changed out the speed sensor, located on the transfer case, and it took care of the problem. The rubber O-ring dries out and fluid leaks into the sensor. At least it did on my rig. Hope this helps.

 

I drove with mine doing this for over a YEAR it was hell. I had toyota stealership GURUS look at at, they couldn't figure it out.

Then I needed a new Battery. I bought a new one, they installed it and every since then its been normal again. I know that doesn't help much but it worked for me.

so weird....

 

Normally, the three most common items to cause this are a TPS, an output speed sensor or a range sensor (neutral safety switch).

Basically, any malfunctioning sensor that can "fool" the computer into commanding a downshift is usually at fault.

Try to have the truck scanned for codes, that may help.

-John