Hello, I need help ASAP. I wanted to see if any of you have possibly had this issue. I was testing my tps sensor and the resistance readings I was getting are out of whack. I figured it was the sensor itself, so I went out and purchased a new one. Yet, to my surprise I am getting the same readings.
I am using “LCEngineerings” page for my testing. According to their specs I should be getting 0.47k-6.1k resistance on terminals VTA/E2 with a 0.0197 feeler gauge. My meter shows 5.9k. Good. This is where it gets strange. The terminals that require testing next are IDL/E2 and should measure at 2.3k ohms or less when a 0.0303 feeler gauge is installed. Mine tested at 5.9 even when I maxed the adjustment out on the sensor. Both my old and new sensor are doing the same thing and I feel like I’m losing my mind.
My question is, is there an adjustment on the throttle body or plate to give the sensor more room to rotate the internal terminals? Or is there something I can do to compensate for the lack of movement required to get to these specifications? I don’t know what else to do and appreciate any information. Thank you

 

It is always a good idea to include as much info about your truck as possible. Year, engine, etc.

As far as the TPS, you've just tested it, or you've attempted to adjust it? I've never read LCEngineerings write up about it, but when my TPS didn't read within spec. I adjusted it using the instructions on 4crawlers site, specifically the 10 steps outlined by "Frankenyota".

Should pop up with a Google search.

 

Theres no more adjustment available than the two screws on the TPS. Did you properly setup the TPS before doing all these measurements? 4crawler has a very easy to read adjustment guide that is for idle/e2 that requires precise movement because a little turn on the TPS does alot to the reading.

Look below the TPS value specifications chart for the one labeled TPS adjustment.

https://www.4crawler.com/4x4/CheapTr...dex.shtml#Adj1

 

Welcome to YotaTech.

I am always amazed at how worked up people get about the TPS adjustment.

First, rather than horse around with somebody on the internet who thinks they know how Toyota wants you to adjust the TPS, I would just refer you to Toyota's Service Manual. http://web.archive.org/web/201108151...93throttle.pdf No "googling" required.

But more importantly, ALL you are adjusting is the switch that opens when you come off idle. What makes it slightly tricky is that open/closed requires definition when there isn't a lot of pressure on the contacts, so Toyota just says "above 2.3kohms it's open, below that it's closed." Next, "idle" requires a little definition (because of vibration), so again Toyota just says "at 0.8mm or more it's off idle, 0.5mm or less it's AT idle."

Assuming your "5.9" is 5.9kohms with no feeler gauge, your switch is not closing. That's all there is to it. So hook up your ohmmeter, and adjust the TPS so it is reliably below 2.3kohms with the throttle closed (and you wiggle and bang on it), and more than 2.3kohms when you open the throttle just a little. You can then double check with feeler gauges, if you want.

Last, with a new TPS this shouldn't be an issue, but older TPS can fail in the resistance trace. Measure VTA to E2. The basic measurement has a wide spec, but what you need to worry about is that the resistance increases smoothly as you open the throttle. If the resistance suddenly jumps up then drops again, you have a bad TPS.

And as 5 Fists suggests, you ought to tell us what you're working on The TPS adjustment is the same between the 22re and the 3VZE, but the 3VZE is more difficult because the direction the connector points.

 

scope told you about all you need to know but ill throw in my 2 cents because I did this last week. the LCE instructions are pretty much as per the service manual, so no issue there. as are 4crawlers. if you have a new TPS, you really only need ot be concerned with the first reading and the other will be within spec. I was also seeing weird reading on the second two checks so I decided to test run it after setting it to the first spec and its running great. be sure to check timing after.

 

Rather than start a new thread on this ancient topic, I'm hoping to go a little deeper into the TPS and code 41 in this one since it has a good start so far.

Truck: 1992 22RE 5spd 4x4
Problem: code 41. Sets immediately after clearing computer, KOEO. Will not show CEL while running but will puke 41 when in diagnostic mode.

I have done all of the static checks per the LCE procedures and things check out. When I do the dynamic resistance test between E2 and VTA there is no linear readout. It skips and jumps all over the place. However, when I take a reading by backprobing VTA voltage at the computer, I get a nice linear reading from 0.45 - 3.85 VDC. How could this be? I set my meter to record max/min VDC while driving around and its always within that range. Can IDL problems set code 41 also? When I backprobe the IDL pin at ECU it shows 0V until slightly pressing the pedal which creates 12V so that appears to be ok. Additionally, I checked continuity of all 4 wires and also checked continuity to ground looking for shorts. Any thoughts?

 

41 is loss of VTA signal ?

You pin is dirty, your connector is loose, you have a broken wire, a intermittent short or you have a failing tps or ECU. Start with the free and easy stuff first, make sure everything is clean and tight.

 

Good diagnostic work. Code 41 is "Open or short detected in throttle position sensor signal (VTA) for 0.5 sec. or more. IDL contact is ON and VTA output exceeds 1.45 V" http://web.archive.org/web/201211190...85diagnosi.pdf I'd say you've done what can be done at the TPS. So now I would move to the ECM and back probe there. (Well, after checking that the connector is good, as suggested by Co_94_PU) A broken/shorted wire between the TPS and the ECM will throw that code.

 

How certain are you you're not getting 51 which is IDL not set (or ac on) while in diagnostics mode

 

Oh that's a new one, or something I've forgotten, I don't recall the VTA voltage over threshold while IDL is set.

 

Good info fellas thanks. Never knew there was a normal and test mode for retrieving DTCs.

I've confirmed that the wiring is good- the only thing that seems to be weird now is the fact that the resistance readings (E2-VTA) as I sweep the TPS are far from linear (all between 3.1-12.1 kOhm however) while doing the same test backprobing the connector at the ECM with KOEO, shows linear voltage and no dropouts. Makes no sense to me. Is 3.8V at WOT too low? (I would think it should be closer to 4.5V - yes the throttle opens all the way to the stop)

I could not duplicate the immediate 41 setting after clearing like I saw the other day but when I drove the truck it came back. I also have a pesky 52 for knock sensor sig which I wont pollute this thread with but its making troubleshooting more difficult because when I'm driving I don't know if its setting a 41 or 52. I usually show both codes after a trip. Anyway back to business- I feel like my idle is a little higher and unstable than it was before having this problem and also a little sulphury smelling so maybe a revisit to the TPS angle is due or there is still a connection issue. Back under the hood.. i'll come back here when I learn something. Im going to remove the ECU and double check all the pins and give them a good cleaning. I hit all my grounds last year so I feel pretty good about that part at least.

 

Yes VTA should be above 4 volts at wot.

 

Had some more time to check things recently.

I pulled the computer out of the truck and cleaned the contacts and harnesses with electrical cleaner and also cleaned the mounting screws and mounting area to make sure the computer was well grounded to the body. Cleaned all connections at the TPS. It feels like the pulsing/hesitation at 1/4 throttle is less and the pedal response is better. However, I'm still getting code 41- sometimes setting immediately after clearing before starting, then other times when I check after a trip.

Tested TPS IDL adjustment and static tests once more with success although it still seems like it's not reaching WOT. The VCC resistance is 5.85k and WOT VTA is 5.15k. Seems consistent with the 3.8V while backprobing at ECM. Definitely short of spec.

Now for the dynamic tests. Ohming VTA is all over the place-far from linear. Anywhere between 2k to 30k ohms. Riddle me this though.. why would I get a perfectly linear voltage backprobing with power at the computer when the resistances are so random at the TPS? That's the only thing keeping me from splurging on a new TPS.

 

Installed a new OEM TPS and the response is much better- no more of that hesitation and uneven power delivery, like getting bullied around by gusty winds on a highway.

The thing that's still stumping me is 100% of the time now it immediately sets a 41 after clearing (no CEL, just shows up on retrieval). Everything is adjusted to spec and I've cross-checked the specs at both the TPS and the ECM. Vcc is a rock solid 5.0V no matter what. But..

What I'm not 100% on is the closed (0.60V) and WOT (3.84V) readings at the ECM. Co_94's screen shot above indicates I'm shy of WOT but another manual I have states that 3.2-4.9V is the WOT range. Which is it? Is my computer toast if it is getting the correct signals and still choking a 41 before I even start the engine? There are a couple more unsolved mysteries my truck has been up to lately that are starting to point to a bad ECM. Not sure where to go to do more diagnosing on this TPS code before sourcing a computer to try. All 3 ECM bat inputs are getting full voltage and the Exx.. grounds all show no resistance.

*UPDATE*

I had two things going on: a dying TPS and likely a bad connection at the VTA pin to the computer. I replaced the TPS with OEM new and adjusted it to spec and noticed better and smoother response. To solve the code 41, a suspected connection issue, I de-pinned all 4 related TPS connections from the ECM harness, cleaned them, and stuck a needle into the female pins to pry on the 'spring' contact in there for more tension to squeeze the ECM pin. Good to go!