# Problem with TPMS False Negative



## mibagents (Aug 8, 2017)

Tonight, when we got in the car the TPMS said our right rear tire was at 18 psi. That seemed odd since we had just had the oil changed and the tires checked, but we pulled over and spent 1.50 at an air pump. It put a little air in it, maybe a pound, then beeped to tell me it was full. We took off, and the TPMS didn't reset, and the readout still said 18 pounds. Stopped at another station and spent another 75 cents at an air bot only to be told it was full and it did not take any air. So the tire is not losing air, but the sensor is reporting a very low tire. It keeps going down, too; when we got home it was reporting like 14 psi. It's not any other tires either, we looked and I'm sure even w/o a mechanical gauge (which I could not find when I wanted it of course) I could tell if a tire was down to 14 psi from 35. I have searched this forum and can't find anyone with a similar problem so I'm concerned, is this such a weird problem or have you seen this and is it as simple as getting a new sensor on that wheel?


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## anthonysmith93 (Jul 15, 2015)

Possible the sensor is going bad or the battery is dying in it for whatever reason, it probably is as simple as just replacing the sensor, but make sure you know which one it is.


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## Rivergoer (Mar 30, 2017)

How old is your car? TPMS batteries start to fail around 5-6 years.


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## mibagents (Aug 8, 2017)

It's a 2013


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## ChevyGuy (Dec 13, 2014)

mibagents said:


> We took off, and the TPMS didn't reset, and the readout still said 18 pounds. ... It keeps going down, too; when we got home it was reporting like 14 psi. It's not any other tires either, we looked and I'm sure even w/o a mechanical gauge (which I could not find when I wanted it of course) I could tell if a tire was down to 14 psi from 35.


I'd still get a gauge and check the tires. If you have a full-sized spare, check that too - just in case.

From the symptoms you're describing, I think a tire is going flat. But the car wasn't reset after the last tire rotation, so it's showing the wrong tire.


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## Rivergoer (Mar 30, 2017)

mibagents said:


> It's a 2013


Depending on build date the tire pressure sensors on your 2013 could be 5 years old. Like @anthonysmith93 said, make sure you identify the CORRECT wheel having the issue and try replacing the sensor. 

Note if your tires were rotated and the TPMS sensors were not reset your Driver Information Center (DIC) will not be synced with your current wheel locations. So your DIC may show a problem with your right rear tire but actually the problem could be another tire. 

So be sure to check ALL your tire pressures, not just the one showing low on the DIC.


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## obermd (Mar 3, 2012)

And buy a 12v air pump. Then you don't have to worry about finding a station with an air pump.


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