Questions and Answers
TPS Testing
Q. Hi Vincent, I have a 95 1.5L Mazda Protege. The manual I have gives very nice directions on how to adjust the Throttle Position sensor. Unfortunately, it's completely wrong (A haynes manual for 93-97)! It claims that the TPS should have no resistance across two of the terminals when the throttle is closed. After completely removing the TPS I checked the different conditions. With resistance between the end terminals and the center pin changes from about 300 ohms to 2k (or so... can't remember off the top of my head). I've done a lot of reading and checking about, but I can't seem to find a description on what resistance I should have when the throttle is closed.
Thanks very much for any help!
TomA. The values are not as important as the fact there is a resistance. My TPS tester and adjustment tool has two LEDs. One that indicates the idle contacts are closed and the other indicates the full throttle contacts are closed. Anything else in between they are both off.
With the throttle closed, there should be continuity between the center and one of the other contacts. Off idle, and there is a spec for this, check your manual for it, there should be no continuity between any of the contacts. At full throttle the should be continuity between the center contact and the other contact. If there is any continuity between any of the contacts off idle and below full throttle, then the TPS is bad and should be replaced.
Generally the idle contacts should open at about 900 - 1000 rpm, depending on the car.
