1998 Jeep Wrangler throttle position sensor voltage too high?

My '98 Wrangler has been having an issue for several months and it's slowly getting worse. It started out that it would only happen when I had been driving on the highway for about 50-60 miles, but has progressed to where it's happening from the moment I start the engine and as I drive around town. What's happening is that the engine will "buck" very hard, almost as if you are alternating between pushing the gas pedal and brake pedal rapidly. As I am cruising down the highway I can slowly push the gas pedal in or let it out, and it seems that there is a single "bad spot" in the travel of the pedal. When it hits that spot it will start bucking and trip the check engine light. A friend of mine runs his own car repair shop and has a scanner that he hooked up to read the error codes and it's saying "TPS voltage too high". According to him the throttle position sensor is only a resistor and is incapable of generating a voltage that should be too high, so he thought it could either be the MAP sensor or the computer. We replaced the MAP sensor but this did not cure the problem.

Given the information provided, do you think it would be worth another $40 to replace the TPS before delving into a horribly expensive computer problem?

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  • 8 years ago
    Favorite Answer

    The TPS is in fact a variable resistor with a 5 volt input so the PCM is always expecting something less than 5 volts. If the TPS is somehow getting shorted out internally then the PCM can get the full 5 volts which would probably be interpreted as a high voltage. Also according to the wiring diagram in my Hanes repair manual the Battery Temperature sensor can play into how much voltage gets back to PCM. I have no idea what that is all about, but it is a third leg in that circuit.

    Source(s): 2000 TJ owner
  • Anonymous
    8 years ago

    Your friend has the tool but no Idea in the world how to interpret what it is trying to tell him. A simpleton but we'll let him slide for his good nature. The TPS is indeed a resistor and what does it resist kiddies? Fish, Harsh language, STD's, or Voltage? Stop screwing around and replace the TPS Dumas!

  • holle
    Lv 4
    3 years ago

    without a wiring handbook on your Jeep, i provides you you a wager - The 'commonly used' thank you to twine the TPS sensor is to take everyday vehicle voltage & feed that into the sensor. The 12 vac then is going by using the sensor, that's in undemanding terms a variable resistor, & into the computing gadget. the computing gadget reads the voltage & estimates how a ways the throttle physique is open. appears like the TPS is going south on you.....

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