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Discussion Starter · #1 ·
So I'm searching for new shoes for the Acadia. Discount Tire has been good to us in the past; so I searched and found some tires. Anyway to make a long story short; as an option they will "rebuild" all my TPMS sensors for an extra $23. I honestly don't think it needs this service; although I am considering having it done. The cost is minimal; I am wondering if anyone else has had this done. My Acadia has 31K on the odometer and I haven't had any sensor issues.
 

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I would have it done. From what I've read about these, they are battery powered and the batteries have a certain lifespan. I'd hate to have new tires put on and then have the TPMS quit 6 months later.

I think I paid about $40 each for a set for the Challenger when I bought them for the new wheels.
 

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Discussion Starter · #3 ·
Batteries make sense; I guess I never really knew how the signal was transmitted
 

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Discussion Starter · #4 ·
Posting as reference; pulled from wikipedia.org:

Direct Sensor TPMS can identify simultaneous underinflation in all four tires in any combination.

Direct sensor TPMS are specifically designed to cope with the effects of changes in tire pressure due to ambient temperature changes and road to tire friction based temperature changes. Friction between the tire and road surface heats up the tire and increases the pressure in the tire. The alarm activation threshold pressures are usually set according to the manufacturers recommended "cold placard inflation pressures".

In order to transfer data from a rotating wheel, Direct Sensor TPMS may use a Radio Frequency (RF) communication channel or an electromagnetic coupling means to overcome the tire/chassis rotational boundary.

The pressure sensor devices of Direct sensor TPMS may be either battery powered or batteryless: Battery powered Radio Frequncy based TPMS have several disadvantages. Batteries eventually become exhausted and represent a maintenance cost to the consumer. Batteries are chemical systems with lifetimes that unfortunately perform very poorly in extreme temperature environments typical of North America and European climates and in aerospace applications. In order to conserve battery life and to conform to various countries communication authority standards for short range radio communications, the power levels of battery powered TPMS are kept very low . As a consequence of these very low power levels, the construction of certain steel belted radial replacement tires and vehicle metallic geometries can block the low power signal transmission paths.

Other disavantage of battery powered direct sensor TPMS are that their physical sensors are quite large and are either mounted on the end of valve stems or by a steel band around a rim's dropwell center. In both cases, these sensors affect a wheel's balance are subject to damage during tire removal and fitting procedures. Banded sensors may also damage the tire bead's air seal. So-called total cost of ownership for direct systems is much higher than for indirect systems due to battery and wheel changes and broken/damaged parts.

On the other hand Batteryless Direct Sensor TPMS overcome these limitations and have the advantage of being maintenance free. Unfortunately, these systems are not available yet on the passenger vehicle market.

AND

Automakers require a battery lifespan of between seven and ten years

So if I have new sensors installed; do I need to have the BCM reprogrammed?

Here is a good website about TPMS:

www.gmtpms.com
 

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Discussion Starter · #5 ·
For reference:

I had my GY's :mad: rotated by Discount Tire yesterday; tires seems to wearing evenly and all 4 were either 7/32 or 6/32 tread life. Service was speedy and the customer service was good. The technicians's torqued my wheels :thumb: although I hope it was set to the proper spec. I asked them if they were familiar with TPMS and relearning tire position and I got the standard yes answer. Well they didn't :-\ but that's ok because I wanted to try out the TPMS relearn procedure in the owner's manual. Everything went smoothly with the relearn and the vehicle honks after each wheel is relearned so you're not wondering if it's done correctly. Overall about 3 mins to do the relearn procedure.
 

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Based on my understanding the rebuild kit does not actually touch the functionality of the sensor or battery. It is basically the mechanism for locking down the sensor itself. I think the purpose is to prevent future breakage of the sensor when the tire is removed again for some reason.

http://www.discounttire.com/dtcs/brochure/general/tpmsRebuildKit.jsp
 

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AA/78U said:
For reference:

I had my GY's :mad: rotated by Discount Tire yesterday; tires seems to wearing evenly and all 4 were either 7/32 or 6/32 tread life. Service was speedy and the customer service was good. The technicians's torqued my wheels :thumb: although I hope it was set to the proper spec. I asked them if they were familiar with TPMS and relearning tire position and I got the standard yes answer. Well they didn't :-\ but that's ok because I wanted to try out the TPMS relearn procedure in the owner's manual. Everything went smoothly with the relearn and the vehicle honks after each wheel is relearned so you're not wondering if it's done correctly. Overall about 3 mins to do the relearn procedure.
I save the three minutes and just make note if front is really front after each rotation. Works for me. ;)
 

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Discussion Starter · #8 ·
I thought about doing that, but my wife will be driving the Acadia to Texas (by herself) in a few weeks and she didn't want to encounter a low tire warning and then fill the wrong one because I was too lazy to relearn the tire positions ;)
 

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AA/78U said:
I thought about doing that, but my wife will be driving the Acadia to Texas (by herself) in a few weeks and she didn't want to encounter a low tire warning and then fill the wrong one because I was too lazy to relearn the tire positions ;)
Kudos to your wife if she would heed the warning. I suspect my wife would just continue on driving. :mad:
 

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Discussion Starter · #10 ·
She would; then the next call would be to me and I would get a :beatdown:; but I guess that's better than ignoring it :thumb:
 

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AA/78U said:
She would; then the next call would be to me and I would get a :beatdown:; but I guess that's better than ignoring it :thumb:
Here's what happens with me - a few days later I see the light/message (my wife is the primary driver during the week) and I ask her "did you see that" - she responds "oh yeah - forgot to mention it". :banghead:
 

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Discussion Starter · #12 ·
:facepalm:

:rant:
 

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We must be married to the same wife! I get into my wife's Jeep and the AC settings are on Low,Low I ask why and was told that's the only way it gets cold :facepalm: Then I look at the message center and it states Service 4WD system. Honey how long has that been on, Oh about a month :tearhair: Oh and by the way th back door is stuck and wont open!!! :help:
 

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Insti08 said:
We must be married to the same wife! I get into my wife's Jeep and the AC settings are on Low,Low I ask why and was told that's the only way it gets cold :facepalm: Then I look at the message center and it states Service 4WD system. Honey how long has that been on, Oh about a month :tearhair: Oh and by the way th back door is stuck and wont open!!! :help:
I swear they would drive away without starting the engine if they could. :thumb:
 

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AA/78U said:
For reference:

I had my GY's :mad: rotated by Discount Tire yesterday; tires seems to wearing evenly and all 4 were either 7/32 or 6/32 tread life. Service was speedy and the customer service was good. The technicians's torqued my wheels :thumb: although I hope it was set to the proper spec. I asked them if they were familiar with TPMS and relearning tire position and I got the standard yes answer. Well they didn't :-\ but that's ok because I wanted to try out the TPMS relearn procedure in the owner's manual. Everything went smoothly with the relearn and the vehicle honks after each wheel is relearned so you're not wondering if it's done correctly. Overall about 3 mins to do the relearn procedure.
AA - Question about this procedure - the manual says to increase/decrease pressure for five (5) seconds but the chirp may not sound for 30 seconds? So do you stop after five seconds anyway and just move to the next wheel or do you have to wait for a chirp before moving to the next wheel? 30 seconds is aquite a bit to either increase or decrease pressure it seems. ??? I know I said I've been just noting front and rear and avoiding this process but after the new tire installation, they're all mixed up if you knowwhat I mean so I want to do the relearn.
 

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Discussion Starter · #16 ·
mike,

Here is what I did; I over inflated all the tires and then started the relearn process. I went to each tire and started deflating using the steps in the manual. Once I started deflating the chirp was well within the 30 second window...........in fact I would say they chirped within about 8-10 seconds. Once they all relearned; I went around and verified all the pressures were good.
 

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AA/78U said:
mike,

Here is what I did; I over inflated all the tires and then started the relearn process. I went to each tire and started deflating using the steps in the manual. Once I started deflating the chirp was well within the 30 second window...........in fact I would say they chirped within about 8-10 seconds. Once they all relearned; I went around and verified all the pressures were good.
Got it - so you waited for the chirp before stopping the deflate and moving on to the next wheel. I'll give it a shot later. Thx :thumb:
 

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Discussion Starter · #18 ·
Yes; I deflated the tire until it chirped and since I wasn't sure how much air I would lose; I started out with over inflated tires. IIRC; I set all the tires to 40 psi; once the relearn was complete; all the tires were at 35 except for one; it ended on 36
 

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AA/78U said:
Yes; I deflated the tire until it chirped and since I wasn't sure how much air I would lose; I started out with over inflated tires. IIRC; I set all the tires to 40 psi; once the relearn was complete; all the tires were at except one ended up at 35; the other tire was 36
Great - I'm off today, its beautiful out so I'll head over to the gas station with FREE air and give it a shot.
 

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FWIW, based on my experience you do not need to keep letting air out until the horn beeps. You just have to follow the manual. I think it says something like ten seconds.

I let the air out for a little over ten seconds for each tire and then quit. Three of the four times the horn beeped almost immediately after the 10 seconds. For one tire it did not but I still started to move on to the next tire and then the horn beeped. I think the horn has to beep before you begin the next tire.
 
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