My vehicle ('03 Impala LS 3.L V6) alerts me when there is a change greater than 12 PSI in my tires. I have gone to Wal-mart to have flat repair done and told them I think I have the TPMS on my car and they said no I don't. My car is not like a caddy, it does not tell me the exact pressure in my tires. Just a change (deflation) greater than 12psi. Is this an actual TPMS or is this something else? I am going to be putting new tires on my car and I want to make sure when I take it into them that they do no mess it up, if they can. They charge 2 different prices for putting on tires that you bring into them. A price for tires w/o TPMS and a price for tires w/ TPMS. I am also looking at having the valve stems replaced too just so I know they are new. Please, if someone can help me on this, I would be grateful. I don;t want to take my car in and have tires and valve stems put on and then have my TPMS or whatever it is messed up because I did not let them know about the TPMS or I was not sure on it. The town I am in is small so there is really not much choice in putting on tires. The "Big O Tires" here has been known to mess up peoples rims/tires/cars. I have heard no complaints on our Wal-marts TLE. If I do have it, where is it located on the car for it to monitor that change?

 

You don't have TPMS. What the car does is use the ABS system to check the rotation of the tires as you drive. When one tire is low it will pick up the tire that has to rotate more & throw the 'check tire pressure' on the dash. You don't need anything special, just regular tires & valve stems. If I'm wrong I'm sure someone will correct me.

 

That sounds about right. My dad had a 04 Impala that he put new Michelins on and he never had to worry about any TPMS. BTW go Michelin or go home

 

I talked to one of the mechanics at Wal-Mart today he basically said the same thing, just not as technically detailed. Thank you so much for explaining how that works. This helps me out big time. Thanks!

DeHartShadow

 

No problem, glad I could help. Good luck.

 

heres the explanation.
on these- the car uses the ABS sensor to detect the wheels rotation. How many rotations per minute for example.

You have 4 tires all the same size. so to travel the same distance- they all turn at the same rate.

If you take 2 circles- equal size they spin the same rate to cover the same distance.
Now take 1 circle and make it smaller. in order for the small circle to travel the same distance as the larger one- it has to make more turns.

apply this to the tire--- as the tire loses air-- it becomes smaller. around 10-15 lbs of air- it is significant enough to cause the tire to get small enough to have to turn more times.
The sensor notices the faster rate of rotation- and alerts the driver.

Off topic.... but youll get the idea...
But youve seen the ice skaters on ice... theyre spinning at a certain rate... as they move their arms closer to their body they begin to spin faster and faster...
If you look at the skater from the sky-- imagine their body and arms as a circle... as the circle gets smaller.. it spins faster.

 

Top notch analogies

 

Indeed! Very good way of making it super easy to understand. I couldn't have said it better myself. Thanks Guys!

 

Thanks Richard, as always an insightful post. This is the forum in action. I always learn somthing new here. Makes it worth my time and effort.