Do these tire caps read pressure?

Hi all,

I have a new-to-me 2011 Tacoma. Dealer didn't know all the aftermarket parts on it during the sale, so I'm slowly uncovering more and more. Recently I noticed there is a TPMS app in my Joying head unit. The TPMS app seems to pretty accurately report my tire pressure, so clearly it's linked to something. Recently my dashboard lit up the TPMS light, so I'm trying to diagnose which wheel has the bad sensor. I instantly turned on the TPMS app and realized it can connect to all 4 wheels, which lead me to believe that the app is taking measurements from something other than the in-wheel TPMS sensors. Then I noticed these tirecaps. They're large and marked with front/back left/right.

Am I right? Do the tire caps report pressure to the TPMS app in my Joying head unit? Or, does it pull from the original TPMS sensors in the tires?

Thanks! Any advice is helpful.

 

No. The sensor is inside the tire, on the end of the air stem.

 

Have you ever linked the OEM TPMS sensors to the Joying unit? Trying to figure out if I can rely on the fact it's not showing back left wheel pressure to replace that TPMS sensor Thanks!

 

@comradeshrek I don’t have a Joying unit. My ScanGauge is supposed to be able to read them, but I’m too cheap and lazy to send it in for the update. I just check at the beginning of every month with a pressure gauge and the idiot light in the dash, old skool, but it’s worked so far. If you don’t have a light, the sensor is working for the OEM system.

 

Take one or more of the caps and put them far away from the truck. Like in your house. Then go for a drive. You’ll know shortly if they are TPMS Caps

 

https://www.amazon.com/gp/product/B07B2S9MJC?ie=UTF8

 

I personally don’t like the caps. They keep the shrader valve open and you are then relying on just the cap to keep the air in the tire. Which isn’t really how the valve was designed to work.

 

How about if you try moving the caps around and see if the readings change. Put maybe 36 psi in one tire and leave the rest at the 27-29 psi they are at. Drive a bit, see if the app shows the new pressure, then change the Capps around and see what the app shows. If the 36 psi tire changes position, then you know the caps are reading the psi.

 

yep

 

Lol so simple yet I didn't think of it. Thanks! Turns out yes, they read TPMS