synystergates

I had my rear wheels replaced at Costco about a week ago and since then I've been having problems with the TPMS light coming on every so often. I've checked the tire pressure on all tires including the spare and they're all fine and up to pressure. No leaks as far as I can tell. Any idea what causes the TPMS light to keep turning on?

MeatRocket

have you ever used fix-a-flat??? just asking, i ruined one of my sensors by using the non sensor safe stuff lol. do you know if they took any sensors out?

SquallLHeart

there's no sensors in the wheels for an '05 man.. and that was silly to check the spare as well... that has nothing to do with the TPMS.

re-initialize the TPMS system... RTFM for that.

dingus

I'm having the same problem except I haven't changed my tires. I checked all the pressures and they're fine I keep resetting it but it'll come back on after 20 mins of driving or so. Also some Toyotas do have a TPMS sensor in the spare.

sciontastic

^^^some Toyota's with full size spares do have sensors. But all Scions have donuts without sensors as far as I know.


You replaced just the rear wheels? Are the rear tires and wheels a different size from the front wheel and tire?

DJ08tC

^^scions do not have a TPMS in the spare.

he has an 05 so there is no TPMS inside the wheel, like squall said he need to try to re-initialize the system

sciontastic

I remember when I had my donut on my right rear my tpms light would turn on 5 miles down the road. figured it was because of the size differences because that how tpm systems for '05 and '06 scions worked. It monitors each ABS wheel speed sensors. If one or more wheel speed reading does not match the other wheel speed sensors or vehicle speed sensor, it will think that the tire is rolling deflated, hence the different size of the spare donut. The small donut spare spins faster than the other bigger wheels and tires

dingus

I have an 05 to, and I have no idea if this is true but one of my mechanic buddies was telling me that there are batteries in the TPMS sensor that eventually die but i know he does a lot of BS'ing so for now I'll live with the light.

tc-guy

05-06 - no sensors.
07-09 - has 4 sensors, no sensor in spare.

if your tires are new in the rear and the front ones have less than half tread, it could set the tire light off on 05-06 models.

dahuisurfer

if you find something that works, do share. i have an 06. got all four tires switched out about a year ago, tried doing everything to make that darn thing stay off, but it keeps coming back. i learned to just live with it, but it would be nice to have it off without having to disconnect it.

SquallLHeart

how many times do i have to say.

RE-INITIALIZE the TPMS...
and if people didn't get the hint.. it's not the same as reseting.

the info is in the owner's manual.. and YES, i'm making people look up that info for themselves instead of just saying the answer.

dahuisurfer

i've tried that. it worked for about ten miles and came right back on.

synystergates

I haven't used fix a flat or anything like that.

I just had 2 tires replaced. Both on rear of car.

How do I re-initialize the TPMS? And, I'm sorry, can someone explain how the TPMS system works on the 05 tC?

rangerryda

iTrader: (1)

We were all noobs at one time, whether it be about cars or forums. Yes the search function is very useful and keeps repeat threads out of the mix but try to help the guy, then flame some.

On the 2005-2006 tC's, the cars computer monitors wheel speed via the ABS sensors on each wheel. Since our cars are equipped with 4 wheel ABS, it can determine if one wheel is spinning faster than the rest because of deflation using these sensors. It's simple geometry and physics, a smaller diameter wheel/tire (deflated) will have to spin faster to keep up with the 3 other properly inflated tires on the car. The car recognizes this and throws the light.

I recommend you go through the Re-Initialization process like previously stated and if that doesn't work, you may have a problematic ABS sensor on one of your wheels assuming ALL 4 tires are very close to the same height. If two on the back are new and two on the front are old, they may spin at different speeds. This isn't really dangerous if they are all in working order and properly inflated but to get rid of the light, they ALL need to be nearly the same height. Pull one tire off the rear and one off the front and compare height next to each other. If a noticeable size difference is apparent, disregard the ABS sensor issue but otherwise, if you are still in over your head, take it to the dealer.

SquallLHeart

btw, if you reinitialize the system properly.. the light should NOT come back on..
because you basically reset it to what the tires are at currently.. then the system will monitor changes from that point forward..

so even if all your tires are messed up and the pressures are all wack.... you can still re-initialize the system....
thus it is IMPORTANT that you check your tires and pressures prior to doing so.

the only point where it may not work is in the '07+ where the actual sensors may see a dramatic underpressure reading, at which then the ecu will not allow you to re-initialize the system.

and since some of you are too lazy to go pull out the manual and find it.. i found the pdf for you to read over yourself..

this procedure does apply to all years..
http://scionlife.org/Scion_Docs/2006_Scion_tC_om/17.pdf

and WHAT DO YOU KNOW! it says to do so
"After replacing or rotating tires or wheels"

what a novel concept! giving people who purchase a vehicle a manual that has information in it!

tc-guy

it may just be because of the rear tires having more tread causing them to spin slower than the worn fronts.

Derrickfernlea

^you mean the rear spins slower than worn fronts.

squallheart... what if someone had staggered wheel fitment in the rear and normal size in the front. can you guarantee that intializing it in that condition will completely clear the light? just wondering.

tc-guy

i stand corrected. edited my post.

rangerryda

iTrader: (1)

As long as the tire height is the same and/or pressure inside the tire (depending on year) then staggered shouldn't matter but as finicky as they can be, who knows. Best fix for the stupid light if you don't care is to take apart the gauge bezel and put electrical tape over that square opening above the circuit board LED.