maskedferret

iTrader: (1)

I originally started a thread about how after getting TPMS modules installed on my new wheels from TireRack, they would frequently malfunction... optional read:
https://www.rx8club.com/series-i-wheels-tires-brakes-suspension-55/wheels-tpms-tirerack-installed-%40-ntb-malfunctioning-122644/

By "frequently", I would have to estimate greater than 50% of the time (at LEAST once a day) after 10 minutes of driving the TPMS light would start to blink.

One thing customer service told me at The TireRack was that they have heard of cases where window tint causes interference in the TPMS system, and may cause the malfunction. My knee-jerk reaction to that was "BS; I'm getting the runaround because they won't take a return on these!".

I have tried everything by the book to try to fix my problem, and finally in the back of my head decided to give this window tint theory a shot. All day today I made it a point to leave the windows up. The TPMS had 4 chances today to malfunction... and it did not ONCE happen! Those of you that are having malfunction issues, I urge you to give this a try; go for a day or two with the windows UP and see what happens. I will continue trying this over the next two days to get some more consistent evidence.

I called The TireRack again yesterday about a possible return (before I tested the theory), and they asked me if I had "reflective" tint, to which I answered no; I have a 35-40% graphite-colored tint on my front windows. It may be possible that although it isn't light reflective, at a certain frequency (say, the frequency of the TPMS module transmitting frequency), the tint could be reflective somehow. With the windows down, it would thus make sense that they could cause interference with some of the modules because the windows would then roughly be blocking between the receiver and the rear modules (RF experts chime in here, please).

If the theory is correct, then my dilemma is this: do I deal with it, get replacement modules, get different front window tint, or ...? What I find interesting is that my OEM wheels with OEM modules and all-season tires NEVER malfunctioned; windows up or down. Could it be possible that these new modules are either just prone to interference in this tint because of their chosen frequency, or maybe have weak batteries / transmitting power?

swoope

iTrader: (5)

wow,
i read this before somewhere. not here.. different car.

why not just put in oem sensors.. you can find them here every now and then, or mazda dropped the price on them...

try onlinemazdaparts.com


beers

NgoRX8

iTrader: (1)

haha... wow...

maskedferret

iTrader: (1)

I decided to do the reset procedure again and drive with the windows up on my way to work... blasted light came on! I don't think I can deal with these finicky things anymore. I'm probably going to return them and try to pick up some used OEM ones off the forum instead.

CTrx8

iTrader: (2)

i wouldn't have even thought to check that. i'm shocked.

swoope

iTrader: (5)

who makes the tire rack tpms sensors??? i would have thought you just got stock mazda stuff from them..

odd.

beers

maskedferret

iTrader: (1)

I'll see if I can find out on Monday when I talk to them again; HOWEVER... I think I have found another possible source of interference that kinda just skipped my mind -- my carPC located in my glovebox. I am leaving it off for the next few days and will now watch for the TPMS light while having the windows DOWN this time. I should have realized the PC sooner.

pdxhak

iTrader: (2)

Why would having the windows down make a difference?

maskedferret

iTrader: (1)

With the windows down, they'd be more in a line of sight cross section between the rear modules and the TPMS controller up in front of the car. If they were 100% effective at blocking RF from the modules, they may be capable of keeping the signal from reaching the controller, thus possibly causing a malfunction. I know RF isn't truly line of sight, but the interference may be just enough.

But anyway - after a day with the carPC off, I have had no problems. It would make more sense with the PC, because I finally installed the hardware around the time after getting the new wheels on.

Dave Gotwisner

I have a similar problem. I replaced my wheels, so decided to keep the Mazda TPMS on the old wheels for when I get rid of the car. I got an aftermarket product that shows temp and pressure for each tire, in a cycle around the wheels.

When the shop installed everything (no tint on car), they had a lot of problems with the right rear tire measuring anything. I have a custom sound system with dynomat, which is metallic, and they eventually thought that was the problem.

The transmitters use the valve stems as antenna, and the receiver is by the rear view mirror.

They switched receivers, with no luck, and put a sensor in a tire about a foot from the rear wheel, it detected it fine. When they put that sensor in the wheel, same problem.

Eventually, it appeared to detect the sensor, so they figured it was working.

A week later, I went in for silver tints (definitely RF blocking). After this, I have gotten false positives (pressure read as high as 70PSI, and as low as 0, temp, the same range). Usually the right rear, but not always. Back wheels are more sensitive than front.

The manufacturer spent several weeks troubleshooting, but was unable to figure anything out. The installers (Mach III in SF) are going to try and do something to better enable the stems to serve as antenna.

I'll know in a few weeks when I take it back.

By the way, Mach III has installed many of these sensors, and never seen this problem before they saw it with mine (or so they said).

MazdaManiac

iTrader: (3)

That is freaky. Plausible and freaky.
Why do you want TPMS sensors, anyway? Is a tire pressure gauge too much of a commitment?

maskedferret

iTrader: (1)

I have no problems with my tire gauge that gets its fair share of use; It's the OCD in me that wants the car to work the way it was intended. Sure, I could just not use the modules and put up with the beeping. Sure, I could put a sticker over the light. Sure, I could cut the TPMS power wire. ... In all honesty, I would have been much happier if TPMS was never a government mandate! I could be $400 richer and not have to deal with this headache.

MazdaManiac

iTrader: (3)

I hear you. Fair enough.
Though, cutting the wire to the secondary power on the module stops the beeping.
I just get the light 20 minutes or 17 miles or so into a drive.

maskedferret

iTrader: (1)

BTW, thanks for blessing my thread with your avatar.

MazdaManiac

iTrader: (3)

Any time.

CTrx8

iTrader: (2)

i'm also of the OCD pack with ferret. for me, i like to have it for when i'm on the road. there are too many times where i start to hear/feel something while on the expressway or feel it pulling and don't know if it's the road, another sound, my imagination, or that there is a problem with the tires. it's just nice to have that little warning so you don't have to pull over every time that happens and know that it'll let you know if there is something wrong.

mysql101

I like the valve stem covers that push out a colored cap as long as pressure is above N psi. So as long as the cap has a color, you know you're good.