On-board Tire Pressure Sensor

[Noloc]

Question: If I replace my stock GrandTrek AT20's with another set of tires ( let's say Bridgestone Revo's) what happens to the on-board air pressure sensor. I was reading through my manual and it mentions that the valve stems themselves contain the module for the air pressure. Is that true or did I mis-read it?

 

[NoDak]

i think in your case since your only replacing the tires, your ok.

page 187:

b. keep the same wheel with air pressure sensor and replace only the tire.


only thing i could find was a notice:

when tires must be replaced, replace the grommet for air pressure sensors as well.

i remember seeing a picture of the inside of a wheel and it having a black sqaure box attached to the center hub.

as long as you dont replace the actual rims you should be fine. if you replace the rims, then you have to go out and buy new sensors and have the new id codes programmed into the TMS.

 

[Noloc]

Thanks for the info !!! I was worried I'd lose the functionality if I replaced the tires. SWEET!!!!

Dunlop AT20 :50cal:

 

[my04runner]

NoDak, how is it the computer reads the sensors? I am working on getting new rims for my truck. Do you know the cost of the new sensors and does Toyota need to put them on?

 

[NoDak]

the sensors have a radio transmitter in them.

price would have to found at a dealer.

page 185 of manual:

system malfunction

1. electric devices or facilities using similar radio wave freq. are nearby
2. a radio set to similar freq. is in use
3. a lot of snow or ice covers the vehicle, in paricular, around the wheels or wheel housings
4. tires not equipped with an air pressure sensor
5. snow tires or tire chains are used
6. non genuine toyota wheels are not used

so 3rd party rims may cause your TMS to report erratic tire pressure depending on the type of metal used in the construction of the rim, if i read that correctly.

 

[my04runner]

Thanks for the info. I will check with them, I had forgotten about those sensors. I hope I can get my new wheels by summer time.

 

[Jim]

as long as you dont replace the actual rims you should be fine. if you replace the rims, then you have to go out and buy new sensors and have the new id codes programmed into the TMS.

if you replace the rims, can't you just move the old pressure sensors to the new rims? am I missing something?

 

[NoDak]

im not sure, but in order for those sensors to stay on at say, 100mph, thats gonna be some sticky stuff to keep it on the rim hub. i imagine if you removed them, the sticky backing will stay on the hub. hence the reason you would need new sensors. im just guessing.

 

[Jim]

NoDak, I just looked in the service manual to confirm my memory. The pressure monitor is part of the valve stem which is attached to the wheel with a washer and nut on the outside. The grommet that you mentioned in an earlier post is the seal around the valve stem and mounts on the inside of the wheel. So you should be able to move the sensors to new wheels and retain the functionality. It would be a good idea to replace the grommet to assure a good seal on the new wheel.

FYI, each pressure sensor has a non-replacable Li ion battery to power the transmitter.

 

[leftyrb]

Toyota sells both a grommet kit as well as new sensors. If all you are doing is replacing tires, advise the shop of the sensors under the rim.

I am using non-sensored equipped valves on 4 wheels, with only the spare having the sensor. The system has worked fine for about 2 months.

 

[NoDak]

thanks for the clarification on the sensor. i remember seeing an actual sqaure unit that attached to the rim hub, but im not sure if this was a toyota TMS or not (i dont quite remember).

in my case, this wont be an issue until i replace the tires, since i gave up on aftermarket rims after my '91 toyota cressida, and just stuck with factory rims.