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?

Update:

Bluto - I posted it in two different categories, one specifically for Jeeps and the other for general maintenance in order to reach a larger crowd.

2 Answers

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  • 8 years ago
    Favorite Answer

    The TPS uses a 5 volt reference signal. The operating voltage is .5 to 4.5 volts DC. If the TPS has a short and the PCM sees 5 volts, the light comes on. Test and diagnose it. If it's bad, replace it.

    Source(s): Master Certified tech, 14 years experience
  • Anonymous
    8 years ago
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