TPS Question

Jason924R

New Member
Joined
Aug 1, 2005
Location
Boone, NC
Ok, so we might have finally found out why my transmission has been constantly overheating. My TPS keeps throwing a code (I'll find it in a minute) and we think this could be the problem. The guy Frank who has been working on it for the past 6 months suggested to me today that this TPS code is the malfunction. The tps is not allowing the 4runner to go into overdrive so it is running in 3rd gear and is causing the overheating. Does this have anything to do with the lockup and all that or does the solenoid take care of that?

So my options are buy a new tps for $140 or dont.

Do it?
 
The TPS is one of the logic decisions that is used to determine the converter lockup yea or nay and at what point it locks up. So yeah, the TP can be the bad guy. And we're back to that lack of lockup causing heating of the fluid in the torque converter.
 
I'm surprised you couldn't tell that it was not in OD before... at any rate, I kinda doubt that is the sole cause... if anything, running around in a lower gear, higher RPM's would help it run cooler.

But, Radioman knows more about the specifics of this trans than I do...
 
If you're talking about a Throttle position sensor, it could be out of adjustment. There is a certain voltage it must be at during a warm idle. If it's out it will run terrible.... If we are talking about the same sensor try to find the factory spec from a Toyota forum or a Factory Service Manual. Usually it is around the .5 volt range. If I'm not talking about what you're talking about then sorry and please disregard...
 
The tranny uses the processed "and" function of the processed output from the computer that comes from the raw TPS signal input plus the PTSP signal from the cable operated switch inside the tranny that's tied to the throttle arm to determine when to lock. It has to get both to determine when to shift gears as well as lock up the converter, and what it sees has to jive with its firmware or it'll do strange things like shift into 4th in the first ten feet of travel, or hold 1st forever, or maybe decide 3rd is the last gear in the box, stuff like that.
 
I don't know how mechanically inclined you are, but this is how I fixed my TPS... I took it off, moved it around some, cleaned up the little metal coilspring inside, re-installed it, adjusted it, and it has done great for the last 7 years. Just a thought!
 
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