Hey guys,
The other day I was easing into the throttle in 3rd gear and my check engine light came on and I momentarily lost power. When I had it scanned it came back as the TP sensor. But the light went off after a couple restarts. Could my sensor be bad or possibly flaky? I do have a ported throttle body so I would prefer to not replace the entire throttle body if necessary. Is there any way to diagnose a bad TP sensor? And does anyone know the cost of only the TP sensor for a 2008 LS3?

Thanks,
Shaun

 

TP sensor is in the the electronic throttle body. Its not like the old cable driven ones you can just replace

 

can you give us the exact code you were triping?

 

Carl if you have a scan tool you can monitor the TPS voltage. You dont even have to start the car. The TPS will output 0-5vdc representing
throttle at rest to full throttle position. You can run the voltage up and down and watch for glitches or points where the voltage dissapears and
reappears. I can appreciate your situation having a ported TB. Good luck,
Leon

 

I believe there a is also a sensor on the gas pedal, and a disagreement between the two can cause a Check Engine light and Reduced Engine Power on the DIC.

Dealer replaced my gas pedal, then bypassed a wiring junction box near the battery, then finally redid some other wiring and that seemed to fix it.

Problem was very intermittant, maybe once every 2k miles. Turning off engine and restarting would clear the reduced Engine Power but not the Check Engine light.

 

I had that due to a ported TB but I only found out because the dealer told me about the code. Changed the TB and saw that it fixed it. Since it didnt interfere as bad as you I put the ported badboy back on and kept on truckin!

If it comes down to it change it and it WILL fix it OR you may be able to get it tuned out.

 

i am experiencing the same problem in my 05..worst case scenario is i will replace it. anybody have any idea how much a TPS is? thanks.

 

I think it was stated that you cannot buy it seperate BUT if my way of thinking is correct then it is the porting job that causes the two to disagree not the sensor itself. Who ported it?

 

my apologies, my TB isnt ported. it is the stock TB

 

TPS is not available seperately. All LS2, LS3 and LS7 use the same TB. Part number is 12570790 and my forum price is $327 (retail is $545) Shipping is cheap from me as well.

RICH

 

So did you get this issue resolved? I have an LS2 ported TB and I am having the exact same issue as the OP. I have tore into the wiring harness under the battery and it looks good. The connectors for the TAC module look great, the PCM is in good condition and the connectors there are clean also. All I can think it is now is the TB or the switch under the pedal inside the car. Just curious if you got your issue fixed.

Daniel

 

To diagnose the TPS sensor correctly you really need an old style analog meter (the kind that have an hour hand like sweeper). An electronic meter or scanner "may" work but they are just not as reliable to see a glitch. I have tested lots of them with a scanner where they looked fine but on an analog meter the glitch shows up.
To diagnose it hook into the power coming out of the tps with the analog meter, sweep the sensor by slowly pushing the throttle down. if bad you will see the meter just loose power all together at a certain point during the sweep. Like i said a simple scanner may work but dont call it "good" until you analog it. Good luck, paul

 

Does HP Pro kit have a selection to read the voltage for the TPS? If so I will just go out with it next weekend and see what it says.

 

I'm having the same problem. Check engine light....throwing a P0121 code...throttle position sensor. How would I check to see it's not the gas pedal. I don't want to spend $300+ on a new throttle body if unnecessary.

 

If you do have a bad Throttle Body and have to replace it, I need some old bad TB's to diesect and figure out what makes them tick.

I will pay you shipping if you arre willing to part with the old broke one. I want to figure out what goes bad and if theres a FIX for them. IF,,, I can fix yours Ill port it and send it back to you!

BC

 

Thats cool, Bill. I would love to find out if there is a fix for mine. I have an ported one already and buying a new one is going to hurt. LOL

 

If it's fixable,,,I can fix it. The last part I asked for I got and I made a self fix for it:

Check out the C5 Ignition Switch repair post that I made:

http://forums.corvetteforum.com/c5-t...ch-repair.html

 

ok guys. Sorry for not replying back lately. I have not got my problem fixed yet. My local vendor offered to check it out for me before taking it back to the dealership. They tried to blame my vararam for the TPS code..

The funny thing is, the vararam has been on the car for 18 months and the alarm just surfaced about 6 weeks ago and I have seen it 4 times in 6 weeks...

 

Let me know how it works out. Im very curious.

 

It's the ported TB. Why, I dont know, but I get a P0121 occassionally. I carry a scan tool and erase the code whenever I do get it so no big deal to me.

I, personally, think it might be the porting job (whom did it, how extreme, etc). Reason I say this is b/c I had my TB RE-ported and since have been getting the code. The 2nd time around porting the TB we went alittle more into it and really pushed the limit of what could be ported/cleaned up.

Like many have said, it doesnt effect the cars performance so either 1) buy a scan tool and clear the code when you get it 2) go back to the stock TB or 3) get another TB ported by someone else and see if you still get codes. I've never heard Spin's TB porting jobs throwing codes so maybe he has the magic hand and does it justttttt right.


Oh- and I HAVE replaced the pedal assembly once before as well. When its the pedal assembly you will constantly throw codes, meaning everytime you start the car and drive away. Once I replaced the pedal the code went away. Then the 2nd TB porting came and now its back "sometimes."