mikes19984x4

can someone please help me out. i need to check my TPS with a volt/ohm meter, b/c i am getting a CEL with the code saying "Throttle Positon Sensor - Circuit A" or something similar to that. What i need to know is if someone has a link to the website or writeup on the instructions of how to test the TPS on the 3.4 V6. i have saw it on here before, but can't seem to find it now. Any help is greatly appreciated....

toyota_mdt_tech

Save your time, replsace it, the code means its seen the fault. A new OE unit is around $60 and it goes on easily, no tricky set up like older models.

mikes19984x4

yeah, i know. but i saw where someone on here posted a link to an article about how you can test the TPS on the 3.4. i am doing this b/c and compare the readings from the testing with the specs, which were also on the article i am talking about, to see if the throttle is opening like its suppoed to...this has been discussed on another post of mine about rev limits of the 3.4. but please, any more help is needed.

toyota_mdt_tech

I doubt you will see any trouble. Its u sually just an quick intermittent open or short. The OBD-II system sees it, but now its probably working fine, you will see a perfectly good working TPS with your meter.

fortinbras

Just wanted to point out that you really want to use an oscilloscope with a variable resistor such as a TPS. If it were a switch, then a meter would do. The reason is that you will not catch minor glitches along the variable resistor with a meter. However, by graphing the voltage level change over time you would usually see spikes or drops. Of course, there are instances where you will have intermitent problems. I would also second toyota_mdt_tech's recommendation. Although I commend you for wanting to thoroughly investigate the problem. Who knows, perhaps the signal/input voltage is the problem. Maybe a ground... I doubt it though ;-)

toyota_mdt_tech

Ah, not quite so (catching a glitch on a meter) we use either a Fluke 87 or a Fluke 88 (have one of each) but the Fluke 87 has a 100 milli-second (Fluke 88 is only 10 milli-second, not quite a fast at catching a glitch) hold/record feature that would catch it. It also have a digitial bar graph on the bottom. We all know looking at a sweep with a digitial gauge is almost worthless, just see a numch of numbers bouncing all over. Thats were the Flukes bar graph comes in nice. But of course, the scope is the ultimate, and it a Fluke 99 etc would have a hold/record feature also. Not a tool aht avarage DIY would have. Ever price a Fluke 99, NUTS!

MTL_4runner

X2

If it were mine I'd replace it if a code was thrown since you rarely get false TPS error readings.

mikes19984x4

thanks for the help guys. i guess i'll be saving up for a new TPS. but still, i want to find out where the article/diagram came from that someone on here told me about. it showed what the resistance should be in the TPS when you ohm it out, b/c as quite a few of us dicussed on my post about my 3.4's rev limit problem, you can supposedly compare these readings with the stock specs to see if the ECU is "seeing" the throttle as wide open or only a certain percantage of wide open. i understand i'll need to just get a new TPS, but i want to do this to the old one first, as i am still trying to solve my 4000 rpm rev limit problem. so thanks again for the help so far, but if anyone knows of the article i'm talking about, please let me know...

j-man

just a thought, go over to TTORA and search throttle position sensor and youll get a million articles - mostly from dennisdawg - he has done a lot of research on the TPS sensor and its probs. Most have probs with supercharged trucks cause they run hotter. And as far as i know, you cant just replace the sensor, you have to buy the whole throttle body, unless you can fix the sensor you have.

mikes19984x4

thanks for that info j-man. i'll definitely check it out.

MTL_4runner

I think this is what you're looking for.......it's straight out of the 1998 4runner FSM.

......and no, you don't have to replace the entire throttle body, the TPS is sold seperately as Toyota_mdt_tech mentioned.

mt_goat

Sounds like you're talking about the drive-by-wire throttle problem on the newer 5VZ trucks (2003-2004)?

mikes19984x4

thanks mtl, that's exactly what i was talking about. i really appreciate it! now i just gotta find time between classes to go test it...lol! but once again, thanks for all the help guys...

j-man

oops, forgot that little point. Yeah, i was referencing the throttle by wire TB's, forgot the older ones werent. my baaaad............

Andrey

you have to replace the entire throttle body (kind of of) in '01-'02 4Runners since Toyota doesn't sell the TPS separately. However, when I ran into a very similar problem, I found the entire TB on the wrecked 4Runner, took the sensor from it and things were good.

toyota_mdt_tech

TPS, you bet you can get is seperately. It retails for around $60.