# Is there a way to test the TPS?



## johnny's90sentra (Dec 30, 2009)

I have a 90 Sentra with just over 70,000 on the clock. It has been a good car for the 5 years I have owned it, but in the last year, the mileage has taken a crap on me. I've changed the coolant temp sensor, the plugs wires cap and rotor, and the air filter, I am now going to clean the AAC. While I'm at it, I'd like to test teh TPS if it's possible. Is there a way to do this? Thanks, John


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## novastar (Mar 14, 2010)

There's a decent guide on eHow, that should help you out.
How to Troubleshoot a TPS sensor | eHow.com


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## bob89sentra (Sep 15, 2005)

The TPS is on the passanger side of the TB or on the left looking at the engine from in front of the car. There are 2 plugs going into the TPS, one has 2 wires coming out of it that go into a grey plug. This is the throttle switch, and if you unplug it and take a OHM meter to the sensor plug you should have continuity only when the throttle is closed. The other plug is black with 3 wires, and has one of those wire clips holding it on, that is the posistion sensor. You can take an OHM meter from the center lead to either top or bottom lead. You should get ~10,000 OHMs one way, and as you open the throttle the OHMs should drop smoothly down into the 100 OHM range. Between the center and the other side it should start at the ~100 OHM range, and go smoothly up to ~10,000 OHMs.
If the TPS were bad, or intermittently faulty you would only notice that rapid changes in throttle, and small amounts of throttle when crusing that the car would tend to buck, or sometimes even bog with slow throttle response.

As for your mileage you can test the O2 sensor functionality really easy. Slide the passenger side seat all the way forward, and access the computer from behind. There is a POT (looks like a flat tip screwdriver turns it) and two LED's with the engine running and warm, turn the POT clockwise till the LED lights flash twice, then turn the POT counterclockwise. when the engine is running the red and green leds should be going on and off at least once per second. If they remain off it is too rich, and if they remain on it is too lean. If you have someone watch those LED's while driving they should be blinking on and off to show the O2 loop is working.


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