: HOW TO: Test/Change TPS (99 STS)

06-09-06, 11:41 AM
Hey guys,

Been having issues with high idling, so I need to test my TPS (Throttle Position Sensor) to see if it's functioning properly...

Anyone can tell me how to find the TPS? any diagrams or links to anything would be awesome.

I already know how to test it, but any extra information would be appreciated!


06-09-06, 03:02 PM

not even a link or anything?
do you guys even know where the TPS is?

06-09-06, 03:17 PM
Locate throttle. TPS is on the side. It's held on with 2 screws and has a small round connector. Autozone or similar should be able to test it.

Don't expect immediate replies... we're slow here. Limit one question per day per customer. ;)

06-09-06, 03:20 PM
The TPS sensor is located just below the ISC motor on the left hand side of the throttle body (looking at it head on). To test is you need a digital multimeter, preffereably one that can record highest and lowest voltages. Connect the negative lead to ground, and the positive lead to the signal output voltage wire. (Dark Blue on my car which is a 98). With the key on at idle, you should read around .45v or so. While moving the throtte plate from idle to WOT, the voltage should progressively rise form .45v to around 4.9v. If at anytime, the voltage drops to 0v, or the mutlimeter read Out of Field Limit (OFL, open circuit), then the TPS is bad.

06-09-06, 04:06 PM
damn.. i wish i had some diagrams...
anyways.. thanks..

06-09-06, 08:18 PM
It is on the side of the TB in line with the throttle plate pivot point.

06-09-06, 11:18 PM
After replacing it.. do you have to do any "re-learns" or any type of calibration or whatever.. or is it just PLUG AND PLAY?

06-10-06, 02:35 AM
I believe in order for the PCM to relearn TPS position, you need to disconnect the battery for 30 second or so. You might as well finish installing the sensor and then just disconnect the battery before you hook up the electrical connector.

06-10-06, 03:14 PM
can anyone tell me if this is correct? whrn i hooked every thing back up as soon as i turn the key on i hear this popping sound. it sounds like the arm inside of the TPS isn't cathing or something. i really need some help.

06-10-06, 03:26 PM
Popping sound? Is it like a continuous, repetative sound? If so it's probably the ISC motor. There's nothing in the TPS to make that kind of noise, unless you were moving it by hand, or with the gas pedal. Perhaps you have a failing ISC motor and just didn't notice before?

06-10-06, 05:54 PM
OK i just tried it again, you can actually see the throttle moving. this is happening only after i take the battery loose and re-connected it. i don't see the ISC doing anything at all. any more tips or tricks? thanks LA

06-10-06, 07:17 PM
After the battery is connected and you shut the car off, does it do it again when you turn it back on? If not, then I wouldn't worry about it. May just be part of the idle learn process or something.