TPS code

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Joined
Feb 14, 2004
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74
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1,052
Location
Sandia Park, New Mexico
The other day I went to start the car and all seemed normal. I went to back up and when I pressed the throttle, nothing happened. To make this short, it only would run when the gas peddle was mashed to the floor. I went to Autozone to get the code pulled and it was the throttle position sensor.
After looking into this, it seems that there is another sensor that is most likely the culprit. I think it was called the throttle motor control. (part # 22060-500-11 C-Dan’s price $189+ tax)
Has anyone replaced this before and were your symptoms the same as mine?
I think this is going to be a plug-n-play part (no setup required).

I also would like to know what code readers you all like to use $45 and up for the dealer to pull the code is crazy. If you have a link, please post.
Thanks,
Dean
 
I haven't replaced that sensor yet. I bought the Innova Equus 3100 code reader (Checker Auto had them for $130.00 less $30.00 mail in rebate)

http://www.iequus.com/item.asp?cid=10

and a Radio Shack multimeter to diagnose a CEL on our Avalon. It turned out to be the EGR position sensor. Following the diagrams in the FSM made the diagnosis and repair fairly easy- a definite learning curve for me, as I'm not an electronics guy.

I think you can test the resistance of the TPS and throttle control motor before you replace anything to diagnose a malfunction, if you haven't already.

The one thing about the code reader- the instructions definitely say to consult your FSM when you get a code for a specific part of the engine, as it may not be the sensor that is bad- it could be a relay, fuse, short, loose connection, etc.

Good luck with your problem.
 
Hank, thanks for the reply. I noticed you are selling your LC, are you going to replace it with a newer one? And if not, want to sell me your code reader &/or FSM?
Code checkers are a good tool, but very limited in what they can do.
I found this datalogger/code checker (http://www.autoenginuity.com/index.html). I use a similar one for my car, but it is only specific for my Mitsubishi and its obd1.
The auto enginuity will check and log a ton of stuff that obd1 cant. It has the ability to check ¼ mile info so you can see if your new mod gives any gain/loss (IE larger tires). I read that it can detect alcohol % in the fuel & Octane rating. I find this to be interesting. I tried to call this am, but they are not opened yet. This feature may not be useable on our cars. The price is not too bad at ~$230 bucks, it lists a lot of other stuff that my not be needed. They have bundled offerings that are quite expensive and software and hardware enhancements as well. I’m not quite sure what’s going to be needed yet. I hope it’s not all the stuff listed, as it will get quite expensive.
Dean
 
Dean, there are two sensors, throttle position sensor and accelerator position sensor. Not the same thing. These were a know fault in the 98/99 years. The truck goes into limp mode and you were supposed to get 25% throttle. Scared the #$*($& out of me the first time it happened. Normally when cold out. I replaced both and did not have the same problem since. I believe the accrelerator position sensor is the one that causes this. The movement side (where the cable attaches) is decoupled from the piece that moves the throttle plate. Somehow the electronics in this gets messed up and it does nor register the cable has pulled the mechanism, so the throttle plate does not open.

It is a really dangerous situation and I believe it should have been a recall, however it never was. Maybe a TSB. Hell if Cevy recalls the cables on the tailgate of the new pickups because the might corrode, you would think that this should have been one as well. Not sure how Toyota gets away with it.
 
DMX84 said:
Hank, thanks for the reply. I noticed you are selling your LC, are you going to replace it with a newer one? And if not, want to sell me your code reader &/or FSM?
Code checkers are a good tool, but very limited in what they can do.
I found this datalogger/code checker (http://www.autoenginuity.com/index.html). I use a similar one for my car, but it is only specific for my Mitsubishi and its obd1.
Dean

There is a definite improvement in capabilities of OBD I and II cars. All the OBD II readers in the US have a common plug in - no matter who made the vehicle. They began requiring them in 1997, I believe. Many of the codes are the same for all vehicles, and then manufacturers had the option of increasing the number of codes they implement in their computer system. These are increasing as time goes on. For simple diagnostics, I like the Equus, but a FSM is needed to follow the diagnostic charts.

I had heard the same thing Christo said about the TPS sensors failing, and I tend to agree that replacing both at the same time would be a little extra insurance.

BTW, I pm'ed you.
 
Yea, the accelerator position sensor is what I am going to replace. But for some reason the dealer/parts guy’s call it something different. The guy at American Toyota, explained that the one sensor talks to the other, but only the AP sensor will cause it to go into limp mode. The code showed TPS. I don’t know why, maybe the FSM would explain this?
I was not planning on replace them both, unless needed. The TPS is only ~$64 from C-Dan. The other sensor is the expensive one.
Dean.
 
This thing gave a code again (PO120 & 121) looks like I need to replace the TPS sensor.
Hank/Anybody, would you mind checking your manual on these codes for me? The TPS sensor is only 60 bucks form C’Dan. If this is the part that needs to be replaced, than can someone tell me what pin to ohm out and what reading it needs to be set at? Thanks
Dean
 
PO 120 - Throttle/Pedal Position Sensor/Switch "A" Circuit Malfunction

Trouble Area: Open or short in throttle position sensor circuit, Throttle Position Sensor, or ECM

PO 121 - Throttle/Pedal Position Sensor/Switch "A" Circuit Range/Performance Problem

Trouble Area: Throttle position sensor

Dean, I'll scan the FSM (6 pages) for you.
 
BTW, did you already replace the Accelerator Pedal Position Sensor when this first occurred? Or did the problem fix itself in May?
 
Thanks Calamaridog! So it looks like TPS needs to be replaced. 6 pages!? Oh my, I hope it’s not that hard to install a TPS. On my car, all I needed to do was adjust it to read between certain values. Are you going to post it here or you e-mailing it?

I purchased the accelerator petal sensor in May and never put it on, until last Monday as it never coded again. Last Sunday it coded like mad, and had to turn it off and restart it to get it out of limp mode. I was able to drive home and replace it. (I had the part with me incase it wouldn’t run.)

I installed the sensor & cleared the codes. I drove 275 miles to another town to see my family and it coded again about 250 miles in.
I’ll be heading back to Albuquerque today and I’ll get the TPS form C’Dan.

BTW, I purchased a code reader, the newer iequus 3030. I don’t like it very much. The cord is too short, and it seems too basic. I’ll probably trade it in for the 3100 tomorrow.
I didn’t get the computer program mentioned above yet. But I’m still interested.
Thanks,
Dean
 
Dean, here is a list of OBD2 scan tools including some reviews. I also have the Equus 3100 and it works fine but if I was to buy one again, I would consider a PDA or laptop based one since they do more. Here's their favorable review on the Equus 3100.

The whole website is pretty good if you lose your manual.
http://www.troublecodes.net/technical/
 
My 99 had the same problem a month ago. It spit out the PO121 code. TPS. It only did it once and hasn't done it since then. If it does I'll replace the TPS first, then the other sensor if that doesn't work. I've read of several with the same problem that happened once then went away. Anyone out there installed a TPS? It needs to be adjusted I know and I'd like to know if that is possible with a common meter.
 
Rule, IMO it should be doable with an ohm meter. I am one of them that said it went away. I believe that it is in fact the TPS sensor, and not the accelerator position sensor that was first described as causing the problem. The good news is that it’s only 60 bucks.
Dean
 
hoser said:
Dean, here is a list of OBD2 scan tools including some reviews. I also have the Equus 3100 and it works fine but if I was to buy one again, I would consider a PDA or laptop based one since they do more. Here's their favorable review on the Equus 3100.

The whole website is pretty good if you lose your manual.
http://www.troublecodes.net/technical/



Hoser, I like the simplicity of the scan tool, however I like the laptop version as this is what I use on my car and it can tell you tons more than a simple code reader. (IE; my water temp gage was reading a little high and was able to tell exactly what temp it was). What information do you have on PDA software? I looked into the scan tool based on your advice.
BTW, I called the other day and found out the 3030 is there best unit now, but I don’t like it because it’s too basic, however it’s easier than carrying a lap top everywhere!
LMK,
Dean
 
Dean,

I'll scan the pages Fri. afternoon and email them to you.

On my Tacoma, I replaced the TPS and it was bolt-on, no adjustment was needed. Don't know if they come pre-adjusted or not?
 
Thanks, I got the TPS today and would like to fix it this weekend. I will be taking it to Texas on Wednesday.
As far as bolting it on and not setting it up, I believe that it could work ok, however the performance may suffer too some extent. It’s possible that it “hit” the parameter that it likes to be in too.
Dean
 
Dean, from what i'm reading it sounds like the tpps is going bad. And if I remember, they are on the passanger side of the throttle body(sorry it's ben a while since I have done one). If it is the tpps, its not that bad of an install. Just be careful of the screws, they are tight and do get stripped out easy. If it's the tps sensor(would be on the driver side) it's a little more complecated. You have to set the sensor to a certain percentage(think it's between 7-14%). Only way I now of doing it a work is by using the Lexus hand held diagnostic tester, going into user data you can see the percentage for the tps. There was a easy way of remembering the codes and what sensor went bad, but cant recall what it was.. Hope that helps.
 
OK, here’s what I did. I removed the sensor it’s a tight fit, but was able to remove it with out undoing the water hose that ran in front of it. After looking over the FSM sheets that calamaridog sent me. I determined that trying to read the setting was not going to happen. (On my other car you can read voltages or ohm readings when it’s properly adjusted.)
So I called American Toyota and talked to a mechanic, he was real cool. :cheers:
We determined that the range is such that installing it somewhere in the middle will probably work. He said to put it on and drive it down and he would read it on his scan tool, which I did. I basically put in on with the same amount of “space” showing in the slot, as the old one had. He scanned it with his tool and said it looked good.

I have the newer scan tool (Inovoa 3030) but it’s not able to read the functions of specific sensors, just if it’s coding or not.
I’m thinking of getting this one (http://www.autoenginuity.com/index.html).
If I used that one, I would’ve set it to the proper setting without guessing.
I thinking I’ll get the PC version but not sure yet. I have a Palm Tungsten E, which is not supported.
Anyone using a good program/datalogger yet?
I hate my scan tool. :rolleyes:
Dean
 

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