hdsalinas

Last night I had to replace the right rear tire with the full size spare (all OEM). I was concern that the TPMS would pick up the signal from the flat tire inside the trunk and not the spare mounted on the car.

I went for a short drive after changing the tire to see that the TPMS gave me an error and everything seemed fine.

Now, do these full size spares (that look the same as the other wheels) have a sensor in them? Anyhow, how does the TMPS knows which tire is mounted where?

pdjv

TPMS knows which wheel by knowing where (on the car) the signal is coming from.

Domm

I believe the receiver is in the wheel well, so it picks up the TPMS based on it's proximity to the receiver. I'm not sure, but I think it also only picks up the signal when the wheels are spinning, which prevent it from picking up the signal from the flat tire.