Throttle Position Sensor Testing and Explanation

Educational video on how the Throttle Position Sensor (TPS) works and how to test for proper operation using a digital volt meter and a Digital Storage Oscilloscope (DSO).

[@Unveildoubts]

Perfect, thank you

[@Mewanrahnam575]

Thanks.

[@BOC4ALL]

How would you test a 3 wire tps? Mine is an 88 sentra with t.b.i. All I have is a cheap multi-meter. Doesn't seem spring loaded. It fits over a shaft sticking out of the throttle body.

[@DrivelineMaster]

Looks like you have a red wire that supplies 5V reference voltage. the black wire is ground and the white wire is the signal wire. The TPS itself should be slightly spring loaded so it stays in contact with the throttle shaft. Even with the cheap meter set it to measure up to 5V. Back probe the white wire as in the video and slowly open the throttle (key on) and watch for the voltage to slowly increase. If it drops down even for a second as you are opening the throttle then your TPS is bad.

[@hondaslave-kd6hi]

Thanks. When checking 5v reference, where did you hook the other connector to? One on 5v and the other to ground?

[@DrivelineMaster]

Correct. I went directly to the negative battery post on the battery.

[@hondaslave-kd6hi]

@@DrivelineMaster thanks. Electrical is my downfall.

[@cal.or7]

Hi my resistance range is supposed to be 1k ohms idle - 4k ohms wot. I get the 4k ohms at full throttle nicely, however at idle rest position my resistance is high 1.85k ohms. My problem I’m pursuing is poor throttle response, delay in response, like a flat/dead spot in the beginning of the pedal travel. Would a high rest resistance cause this?

[@DrivelineMaster]

a short answer is yes even though there are other items that can also cause these symptoms. Resistance with an Ohmmeter is not a very good way to test a TPS. Voltage should be used and of course a scope is the best way. Some TPS sensors are adjustable and if someone messed with it that could throw off your measurements. You could also have carbon buildup on the butterfly valve. If you can get in there you might try cleaning the valve and throttle body with some carb cleaner or other suitable solvent. Try searching KZbin for Throttle body cleaning.

[@Work782]

Note2Self @ 1:42 = Back Probe Pin

[@Anon_PK]

Why my tp sensor showing 2.9v at WOT. Please guide Thanks in advance

[@DrivelineMaster]

Please provide me with the year, make and model of your vehicle and I will try to give you some help.

[@Anon_PK]

@@DrivelineMaster Thanks for your prompt response. It's Honda 2005 Keinh company 3 pin tp sensor

[@DrivelineMaster]

Hi Danish, I was hoping for a little more information so I could look up your specific vehicle. 2005 Honda helps but is it an Accord? DX or LX? engine size. All this can help me to provide you with the right information. One thing you can do is unplug the TPS, With the key on very carefully touch each wire on the wire harness side. One should have 5V, two should be zero or almost zero. One wire is for ground and the other is the sensor wire. If you only have 2.9v on one wire you need to know where that wire goes into the control module. You need to test the voltage at the module. If you do have 5v then you might have resistance problems on the ground wire. If I can get some more vehicle specific info I can be more detailed.