texian

Yesterday morning, I got my first diagnostic light...tire pressure low.

The tires looked ok, so I began to drive it in to a shop. After about 15 miles or so, the light went out.

I got it into the shop. They said one tire was about 2 lbs shy, but they didn't see a leak or anything, so they reset it and said it should be fine.

The same exact thing happened again this morning.

Anyone have any ideas what this may be?

Thanks.

O.R.A.

Has it been significantly cooler in the mornings were you live?

If so, the cooler weather will affect (lower) the pressure on the tires. As you drive the car, the tires warm up and the pressure increases. You might be at that threshold level for the sensor to trigger.

This is just my guess...

TreknMazda

Yesterday morning the temperature was in the nippy 40's. I started up for work and got about 500 feet when the TPMS light and buzzer came on. Did a quick visual on all the tires and they looked okay. Pulled back in to my parking spot and got the gauge out. Every tire was 28lbs, 4 lbs low. (The last time I checked them they were 32lbs) Using the handy Mazda air compressor I added enough air to get them back near 32 lbs. Drove to work, no light, no buzzer, no problem. Did a quick check of one tire and it was 34lbs (after a 26 mile commute and speeds up to 80) All tires were 30-31 lbs at ambient temperature when I left work for home again. It was even colder this morning (high 30s) but TPMS did not light.

Gord96BRG

It sounds like it was just doing it's job. Pick up your own tire pressure gauge, and if it lights in the morning again, get out and check all 4 tires' pressures. You might have a slow leak in the one tire, or it could just be the colder morning temperatures are causing a drop of a couple psi.

Regards,
Gordon

Visa

My brother had a problem with 2 of the valves within the first 2 weeks of getting his...

Though I don't think he had flats but something went wrong with 2 of the valves instead. This is in Houston in August, also, so not exactly cool weather by any stretch...

Haven't had any problems with mine after only 2 weeks, crossing fingers

Haze

I have a feeling that the tire pressure sensor is going to be a constant annoyance for the life of the car. I love the government. Why they think that they know how to design cars is beyond me.

DisneyDestroyer

I had this happen to me, it only takes about 2 pounds to go off.

After a while it started happening more frequently, eventually it would be 6 pounds every morning after just sitting over night. It turned out that I had a faulty valve stem that was leaking. Watch that tire carefully, from my experience it's the tire not the sensor.

zoom44

always check the pressure in the morning before driving. adjust the pressure as soon as possible to bring it to 32. if you have to drive remember that your tires have now warmed up so add (or subtract) enough to cover the difference when you first checked. if it was 30 when you first checked add 2 pounds. dont drive to the air pump and read it again at 31 and just add 1 pound because in the morning, when the tires have cooled, you will get the warning light again.

mikeb

I'm glad I havent had to see that light come on

lefuton

i had this come on for me last thursday, i had checked the weekend before and all the tires were 29.5-30psi cold...then i got had teh same experience, 500 feet out of my cul-de-sac and it came on. i ran around the block and back home and all 4 tires were between 23-25psi. was strange =p anyhow $0.50 of air took care of that =)

RX8-TX

Texian, the weather has been kindda cooling off for us here in N.Dallas. I could not assure you anything, but its very likely that the TPMS saw one (or all four) of your tires drop in pressure due to the cool temperatures. If you were to drive for awhile with the TPMS ON, Im sure you would have see it go away due to the temperature raising at the tires.

Use the compressor that came with the car, and check their pressure yourself before you go out, or early morning. Make sure they stay put at 32psi (220kPa)

That should get them at 34~35psi after driving your car on a commute and not below 32psi after a long period of non-driving.

As the manual says, you should check the tire pressure every season (ha!) or everytime there is a drastic ambient temperature change (the case now!)

Good luck, and don't panic, I seriously doubt its a malfunction. Oh! last thing, try to always use the same device to check your air pressure...if the compressor's is not practical for you; you can get one at Super Target or any other store. Don't trust the pressure reading, but use it to compare pressure levels from time to time. If you notice a big difference....unpack the compressor.

Cheers!

danRX8man

Are the tires supposed to be at 32psi after warmed up or when cold?

RX8-TX

Nothing is specified, so Im assuming 32psi is ambient temperature pressure.

zoom44

it is not specified but like i said if you bring the tires to 32 when warm then when they are cold they could be below 32 thus giving you the light. it's best to take them to thr proper pressure when cold.

r0tor

iTrader: (1)

Happened to me this morning - there was actually frost outside!


Anyway, I just whipped out the air compressor in the trunk and I found every tire was down 20kpa (whatever that is in psi). Blew them back up to 220kpa (whatever that is in psi) and everything is right in the world again.

Edge

This has been happening to me for the last week. I've had 5 false lights so far. Our temps are ranging from 65 at night to 95. I've had the light at 95 and at 65. I drove less than a mile to a gas station, checked the tires and they are all at 32 psi or 32.5.

Seems like I may actually have a failure. Originally it seemed connected with driving through large puddles, but the last one when I actually checked pressure instead of just kicking the tires was dry and in the morning (temp less than 70).

Ideas?

eccles

A couple:

• Don't ever rely on gas station pressure gauges. They get knocked around, run over, and generally abused in every possible way. Invest a few dollars in your own personal gauge. The type with the calibrated slide-out stick is more accurate and rugged than the dial type.
• If you insist on using the gauge at your gas station, try pumping them all up to 34psi on their gauge and see if that resolves the problem. If the light is coming on only when your tires are cold, chances are good that your pressures are borderline low, and I would believe the onboard sensors before a gas station gauge.

P00Man

what if some of them are 32.5 and some 32, wouldnt that discrepency trigger the light?
________
Free Vaporizer

eccles

No, the system doesn't care how disparate they are, only whether one or more are above or below certain preset limits. It appears that the low limit is somewhere around 30psi, and the high is somewhere around 45psi - I get a light whenever I pump mine up to 46 for an autocross.

VividRacing.com

My light hasen't come one yet. If they were a little low then that would make sence that the light goes out after it's warmed up. It only takes a 1-2 miles to bring the temp of the tire up enough to raise the PSI level in the tire.

Edge

sorry, should have been more explicit. i drove to the gas station for easy access to free air. i used one of the calibrated slide out stick stick guages to check, so i'm pretty certain i was reasonably accurate.

if it continues, i'll just pump 'em up to 35 when cold and see if it continues. if it does then i've probably got a failing sensor.

sohcpunk

I've had the tire pressure light come on after 15 mins of driving and I keep the pressure at 32 psi all the time. Been back to the dealer for the 3rd time and after they test drove the car the whole day, they are gonna have to order me a new tire pressure module. Hopefully, it will be here as soon.

zoom44

no they may not have to. the tpms has a low and a high set point. perhaps once you drive around for awhile your tires warm enough to pass the top set point. they should be able to go in and set that point higher.

sohcpunk

No idea, I'll just let the dealers handle it, I think they called the Mazda tech support because they don't know whats going on.