• If you currently own, previously owned or want to own an Avalanche, we welcome you to become a member today. Membership is FREE, register now!

TPMS sensor failure

speedysteveabz

Full Member
Joined
Dec 28, 2012
Messages
95
Hi,

one of my tyre sensors has gone crazy, reading randomly between 90 & 5 psi Im guessing the battery is on the way out.

Can the battery be replaced or do I need a new unit ? I've seen them online for about $30 but obviously it needs the tyre removed to fit it.

Ive called around a couple of tyre places with various answers from "no we dont change them" to "sure we can do that for $200"

Seems like a lot of money to change a $30 part, is it worth trying this myself if I buy a Harbour freight tyre changing tool ?

SS
 
Same here, I bought a new one at a GM dealership in Canada. Purchaseprice $ 35,= CND.
Way cheaper than in the Netherlands. Still got to replace it with the old one, but since I have a shop of my own it wouldn't be too hard.

 
Go into the tire shop and see how much they charge for a tire patch (not a plug) they have to remove and re balance the tire to do it. When they tell you $15 bucks (what I have found to be average charge) tell them you need a new valve installed instead!!!!
 
forgot to ask, as one sensor has gone out ( its a 2007 avy ) are the rest likely to do the same soon ?

Has anyone tried the harbour freight tyre chaging machine ? is it up to the job of doing our size tyres ( I think they are 17" and the machine spec says 16" max ) I dont mind investing $40 if im gonna use the machine a few times.

SS
 
Just thought Id let yall know that I bought the HF wheel changer for $35 worked great no problems breaking beed of tyre, you can get enough access to change the sensor without removing the tyre, breaking the beed is enough, changed out the sensor with an Ebay sensor ($30) reinflated tyre drove around for 10mins to "activate" the sensor, did the relearn procedure by bleeding air out of tyres in order and its worked perfectly !
Gonna try digging out the battery from the old sensor ( see U-tube ) and replacing it in anticipation of the next sensor die-ing.. given they were all original equipment its very likely the rest of them will start failing soon. Basically saved myself a bunch of cash vs having the dealer or a tyre shop do the work & now have a wheel changing tool for next time.
Its an easy job !!
SS
 
That's great....and thanks for the info.  (y)
 
TPMS battery removal, well that was a bit more challenging than expected or than the U-tube videos suggested, on a corvette the potting compound that is used on the sensors is apparently soft and can be dug out with a screwdriver unfortunately thats not the case with our sensors.. the potting compond is rock hard and bonds the entire battery and circuit board along with connectors, I managed to wear it away enough to remove the battery without ( I think ) damaging anything else, I still have the connectors sticking out and they are in good shape but had to cut away all of the potting compound around the battery, unfortunately this process has completely removed any identifying marks on the battery so working out the exact specification of a replacement will be a challenge.. its 20mm diameter, 4mm thick and is currently putting out 2.85v so im guessing it used to be 3 or 3.5v before it discharged. Gonna go to Batteries plus store and see what they have.

Does anyone know what the spec should be ?

SS
 
Went for CR2032, a little bit smaller in thickness and I suspect wont have a very long life ( still hoping for a couple of years though ) but easily available and seems to fit OK, soldered the connectors on ( as quick as possible so I dont cook the battery ) then cover up in DEVCON to hold it all together gonna change out another sensor ( which went out this week ) for the "refitted" one this weekend and see how it goes... hopefully this will work out and if I repeat the process on the other wheels it will be a complete change of sensors for a little effort and no money  :D

 
pic of sensor showing terminals and groove for the battery after dremeling off the original epoxy type coating
 

Attachments

  • tpms.jpg
    tpms.jpg
    32.9 KB · Views: 70
bit of an update, ebay sensor still working good & have now cut open "repaired" and replaced 2 additional sensors as above, one seems to be working fine the 2nd worked for a couple of days but has started acting up again, the 2nd one I did have some problems getting the solder to stick and I may have pushed too much heat into the battery, gonna pull it out and have another go at it.

As suspected all the original sensor seem to be dieing more or less at the same time so I guess the battery life is pretty consistant..

At least im now an expert at popping the tyre beads  :rolleyes:
 
sure enough the dodgy repaired sensor solder had split from battery and was giving an intermittent contact, split off the devcon ( much easier than the original encapsulation ) replaced the battery with a fresh heavily cleaned and sanded one, used the smallest solder wire I could find with an electronics sized soldering iron, recovered in devcon, let it dry, installed and all has been good for 5 days... bought one of those CUB tpms sensor trigger tools from Tire Rack for $20 saves a lot of hassle with the deflate / inflate process which seemed to only work intermittently ( I know its a bit of a waste of cash but I like tools & a few of my friends have cars which this will work on to so I justified it as an investment  ??? ) so the sensor repair can be done if your willing to spend the time and effort on it.... I guess not that many people would bother for something like this but Im a Scotsman and you know the joke about  "how was copper wire invented ?".............................................. 2 Scotsmen fighting over a penny............................ :laugh:
 
I bought the reset tool for my wife's Ford Flex.  It's so I can reset the sensors when I swap from summer to winter tires and back again.  Not a waste of money at all when you figure shops want to charge $50 to do it.  It pays for itself on the first use.

I have a question regarding the Harbor Freight tool.  What do you do about balancing the tires?  I've seen that thing in adds a few times but have always shied away from it since I have no idea how I'd balance the tires afterwards. 
 
no need to balanche the tyre, as its never being moved relative to the wheel, only breaking the bead on one side swaping out sensor then reseating bead back exactly where it was
I guess technically the devcon may weigh a gram or 2 more than original encapsulation material but that amount of mass is totally irrelevant..

If you do actually pull the tyre off completely for some reason mark it before hand with a pen aligned to the tyre valve and put it back in the same place & again youd be fine.

Only time you really need a balance is if you actually change the tyre for a different one. HF do sell tyre balancing equipment which should work adequately in my opinion if its a back tyre dont bother balancing as you wont notice unless is an extreme amount out of spec, front tyres do need balanced as the shimmy isnt pleasant I would just go to a shop and say youd lost a weight they would do it dynamically on a machine fora couple of bucks.

SS
 
Back
Top