Can a malfunctioning TPS cause an automatic transmission to have difficulty changing gears?

I have a 2000 Honda Civic EX, recently it hasn't been starting normally. I have to press the gas pedal after releasing the key and it will sputter to a start. There's a strong gasoline smell afterwards, and unspent fuel out of the exhaust. A coworker's husband is restoring a car (so I assume he knows what he's talking about) and helped me to try and diagnose the issue. He said I'm looking at either the TPS or the IAC.

When I got home I did some research and under the symptoms of a malfunctioning TPS it read

Difficulty changing gears

Poor fuel economy

Stalling at idle

I've been experiencing all of those recently, but I attributed the transmission issue to a malfunctioning transmission (sometimes* not always, my transmission will shift hard and it will shift from first into second, and "slip" immediately into 3rd, then it transitions into 4th perfectly. This doesn't happen always and there's no grinding noises, etc). I've been entertaining the idea that my transmission needs to be replaced, but if a malfunctioning TPS could cause that, then well that's a huge weight off my back.

Any and all information is greatly appreciated.

6 Answers

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  • 8 years ago
    Favorite Answer

    The TPS can cause poor running conditions that can cause a jerking or stuttering type of motion when the vehicle is switching gears or from idle in park to drive.I'd start with perhaps removing/cleaning/replacing the TPS.Check all the vac system, vac lines/vac hoses etc and clean different sensor wire plug in connectors/connections by unplugging them one at a time and use tuner cleaner/electrical contact spray.Take some throttle body cleaner clean the throttle body , be sure to clean the areas where the TPS or IAC sit.

    Don't forget to check the transmission fluid level/quality and monitor the transmission how it shifts, especially once you fix the main problem such as the TPS or IAC etc bec the shifting or transmission problems maybe related.Note if you've not changed the transmission fluid/filter within the last 3-5 years it maybe a good idea to change them asap.

    Hope that helps and best of luck.By the way it might be a good idea to have that system scanned bec there maybe a error code/codes stored even though the engine light may not have indicated any problems. A full diagnostic scan may run a few bucks but it should be able to monitor the TPS and IAC sensors systems and detect any malfunctions.

    Note if your looking to do the work yourself or have a friend do it, plus maybe save some cash you may want to try a good U pick auto wreckers and pull not only those two sensors but maybe a few others or extras and perhaps extra vac lines,vac hoses,vac junctions/connectors.

  • 4 years ago

    This Site Might Help You.

    RE:

    Can a malfunctioning TPS cause an automatic transmission to have difficulty changing gears?

    I have a 2000 Honda Civic EX, recently it hasn't been starting normally. I have to press the gas pedal after releasing the key and it will sputter to a start. There's a strong gasoline smell afterwards, and unspent fuel out of the exhaust. A coworker's husband is restoring a car (so I...

    Source(s): malfunctioning tps automatic transmission difficulty changing gears: https://biturl.im/q9nCP
  • Dan B
    Lv 7
    8 years ago

    The problem with taking your transmission to a transmission shop is that they don't know how to FIX transmissions. The only thing they do is OVERHAUL them. The Throttle Position Switch could have an effect on transmission shifting. The transmission shifts according to the throttle position and engine load (measured by manifold vacuum).

    The starting problem and strong gasoline odor is highly unlikely related directly to the transmission. The TPS is mounted somewhere on the throttle linkage. Most cars don't need you to press the gas pedal (old school for setting automatic chokes). The computer decides how adjust the fuel mixture for proper starting. There may be a pending trouble code in the OBDII history. See if anything is there. A pending code does not necessarily set the CEL light.

  • busbee
    Lv 4
    3 years ago

    Throttle Body Sensor Symptoms

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  • J J
    Lv 7
    8 years ago

    The TPS is the sensor that tells the ECM how fast you want to go. Got nothing to do with the trans the IAC valve is the idle air control, could be the reason for the sputtering start and no doubt the stalling at idle, not the trans problem either.

    Poor fuel economy could be that smell of gas you get after starting, I'd look for that first. If you can smell it you can see it. Next thing I'd look for is a broken shift cable (runs from the throttle control to the trans) on the throttle control valve since your going to clean the IAC valve that is right there. Things should improve for you then.

  • bo
    Lv 7
    8 years ago

    yes a malfunctioning t.p.s sensor can effect transmission shifts

    Source(s): transmission man
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