TPMS Sensor

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Feb 18, 2011 | 10:35 AM

mandyfig

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From: GA

TPMS Sensor

Question for the experts:

Does the TPMS sensor activate the TPMS light if you have your tires running at 35+ or higher psi?

We know it sends a low pressure signal if it falls at a certain psi. Maybe 28 psi?

How about the opposite way? One would think not.

Anybody in the know?

Feb 18, 2011 | 12:31 PM

VVTiBob

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From: CA - San Diego

sent you a PM, but it did not include one part: you can register two values, one for each set of tires you might use. The rest is in the PM

Feb 18, 2011 | 01:15 PM

mandyfig

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From: GA

Thanks Bob.

I know about the 2 set up values used for summer and winter modes. This is related to the frequency in which the sensors are transmitting the signals. TPMS must have the same color codes (which means they transmit on the same frequency). I think there are 5 colors (types) for Toyota.

Feb 18, 2011 | 01:28 PM

mandyfig

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From: GA

So from what I understand here's how the TPMS works:

1. TPMS sensors will send signals via rf spitting out equivalent psi readings. All 4 sensors do.

2. Processor will ID the psi and make sure it is within the minimum psi (maybe 28...this is unknown but not important) no maximum psi given. This signal is sent periodically do not know how frequent. But I believe it is not minutes but hours on end. It took my SC 2 hours running before realizing that it was not getting signals. It turned on while we were on the road but shortly after I went into the garage, the TPMS turned off.

3. When processor sees a delta between the last signal (for example 32) and the latest signal says 26...or less...the processor triggers the TPMS light to turn on.

4. Or maybe a battery is out and 1 signal is lost...TPMS light is activated.

Anybody else have an input?

Feb 19, 2011 | 09:36 AM

scdroptop

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From: Tx

I don't think the max psi would trip the light...I'd chase the battery issue after you check your psi of course!

Also, dramatic changes in weather here in Dallas (similar climate to you guys in ATL) sometimes make my TPMS on all three of my cars go nuts.

Feb 19, 2011 | 05:52 PM

OBP

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From: NJ

Mandyfig, on the min PSI to trigger the TPMS warning light, its value is set by the dealer. I know because I had to get my winter tires' TPMS registered once and the dealer told me they set my winter tires' TPMS to trigger at 27 PSI.

Feb 20, 2011 | 06:11 AM

mandyfig

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From: GA

Thanks good info. There are 2 sensors in the TPMS. 1 for air pressure and 1 for temperature. The temperature sensor side is face down close to the rim. The air sensor is located on a small hole.