txguy3312

Ok, this is long, so you can skip to my questions at the end if you want to skip a bunch of detail...

I experienced a flat tire (rear driver-side) and took it to a national chain tire shop to be fixed. They said they don't do plugs, just patches and would need to replace a part on the tire related to the tire sensor. It was a $15 part.

Immediately upon starting my Tahoe after the tire was fixed, the warning message "Service Tire monitor" displayed on the dash. It had never been displayed until after they removed the wheel to service it. I went back into the tire shop and they said, "just drive it for like 50 miles and it will reset itself." So I did. And it didn't.

I went back once and they cleared the message but it came back on within a day. Then I went back and their diagnostic device was broken and a new one was in transit by UPS, so no joy.

Finally, I went back yesterday and had my vehicle inspected and requested that the tire monitor issue be resolved. They kept me there 2.5 hours and I overheard the manager telling the assistant to "give it another 30 minutes" in a hushed conversation. (i pretended not to hear them.)

I asked if my car was ready and was told that it was still being inspected. I looked out the window and it was parked and I told him it looked done. That's when the asst manager "found" the plastic envelope on the counter next to him and said, "Oh, it was here the whole time. We scanned the system and the problem is with your FRONT wheel driver side and we are working on an estimate for you."

I got my Tahoe home and noticed that the tire stem on the front tire driver-side is silver and the rest of my wheels have black stems. I would expect the "odd-man-out" should have been the wheel they serviced the first time, the one they put a new stem/sensor on as part of the tire repair -- the rear driver wheel. I think they swapped the front and rear wheels so the problem would not be on the wheel they originally serviced.

QUESTIONS:
Can you determine which wheel sensor is defective by scanning the computer? Or do you need to test each sensor individually?

Is there a "history" of codes that could be pulled or some way to determine if the wheel had been switched? I was wondering if the wait time was them trying to get the computer to register the problem as front wheel instead of rear wheel.

Does anyone know how to determine if the silver stem is a part normally used by F___S____ stores (think "flame-rock") and, therefore would have no business being installed on a front wheel when I have only used them for the rear-wheel fix?

Thank you all for your expertise and any suggestions! I just want the issue fixed but don't want to pay for a problem that seems to have been caused during the initial tire repair. I feel I should have some proof before I approach the company rep above the store manager and request repair by a different company store location.

73shark

Welcome to the forum.

First, my wife's 2004 Tahoe came w/ the metal stemmed TPMS stems. Second, I just replaced them due to the batteries starting to fail. Service said they're good for about 7-8 years. I believe that the tool the tire stores and dealers use will tell you if each sensor is bad or good.

Do you know if yours are original?

txguy3312

Thanks for your reply. I was mistaken in my first post. The stems are all metal and gray. The stem caps are 3 black and one silver. And the silver cap isn't on the wheel that I would expect it to be.

What they tell me needs to be done now is replace the tpms sensor at a cost of $150.

The part they replaced when they repaired the flat tire was related to the TPMS system but was only fifteen dollars. I was thinking that part came with the silver stem cap?

I was just wondering if they damaged the tpms sensor when they took the tire off of the wheel to repair the flat. Would that explain why the "service tire monitor" message came up immediately when I turned the ignition key after the tire was patched? I didn't even put the vehicle into gear when it alerted. I was like, "well, I've never seen this before..."

But your question got me thinking...maybe I should take the vehicle to a different place and see if they can tell if the 3 black capped stems are the originals and the silver cap is "new." If so, the only way for it to be on the front rather than the back is if the shop moved it yesterday from the back location where the flat occurred and was repaired. And I don't see a reason to switch the wheels on that side other than to be able to say something like "the problem is a broken sensor but it isn't the one we touched so not our fault..."

I guess I will do that for now...
Thanks again for your thoughts!

tech2

the original tpm with silver aluminum valve stems come with metal silver caps. The caps can seize on so plastic caps could have been installed at any time.

Typically when the tpm light is blinking, there is a system problem. When the light is on all the time, it is a low pressure condition.

Does your truck display tire pressure through the instrument cluster?

A code can be set for the r/f tire but the bad sensor can be at any position if the tpm were not registered after a tire rotation. That is why the tech should re-register the tpm to locate the bad sensor and not go by the location determined by the dtc.

The tpm can be damaged by the bead breaker or during a tire dismount.

Each tpm has a unique number that is stored in the rcdlr module.

73shark

The metal stems are the originals and they came w/ metal caps. If they only charged $15, I'm guessing they just put a regular valve stem in.

I bought four for about $150 on ebay and paid $75 for install and register. They just broke the bead down at the stem and R&R it. No need to rebalance then.

MDTAHOE

Any time the bead is broken the balance should be at least checked. 80-90% of the time they are out of balance.

73shark

Even if they just break it at the valve stem, not all the way around?

MDTAHOE

It as a policy at my to always at least check it after. Most of the time they are out of balance. Keep in mind though any tire that has been driven on for any length of time is most like already out of balance (maybe not enough to feel it yet). It is better to be safe then sorry. If the customer feels something after they pick it up all they know is we touched it last and they have to return.