From: SMS on
My TPMS warning light came on this morning. It also happened to be one
the rare sub-freezing days we get in Silicon Valley. The tires are fine.

Is it best to ignore the light, or add air to compensate for the lower
pressure caused by the cold weather?
From: C. E. White on

"SMS" <scharf.steven(a)geemail.com> wrote in message
news:4b1e7b10$0$1641$742ec2ed(a)news.sonic.net...
> My TPMS warning light came on this morning. It also happened to be
> one the rare sub-freezing days we get in Silicon Valley. The tires
> are fine.
>
> Is it best to ignore the light, or add air to compensate for the
> lower pressure caused by the cold weather?

I'd add the air. Be sure to check the spare as well. Both my SO and
Sister had the light come on becasue the spare was low.

I was under the impression that the warning light only came on if a
tire was around 10% to 25% underinflated.

Some interesting information on the Toyota system at
http://www.toyotatpms.com/index.htm

Ed


From: Ray O on

"SMS" <scharf.steven(a)geemail.com> wrote in message
news:4b1e7b10$0$1641$742ec2ed(a)news.sonic.net...
> My TPMS warning light came on this morning. It also happened to be one the
> rare sub-freezing days we get in Silicon Valley. The tires are fine.
>
> Is it best to ignore the light, or add air to compensate for the lower
> pressure caused by the cold weather?

I would check all of the tires, including the spare, with a tire pressure
gauge and inflate to at least the pressures indicated in the owner's manual
and on the driver's door or glove box door.
--

Ray O
(correct punctuation to reply)


From: JoeSpareBedroom on
"Ray O" <rokigawa(a)NOSPAMtristarassociates.com> wrote in message
news:hfm54g$flk$2(a)news.eternal-september.org...
>
> "SMS" <scharf.steven(a)geemail.com> wrote in message
> news:4b1e7b10$0$1641$742ec2ed(a)news.sonic.net...
>> My TPMS warning light came on this morning. It also happened to be one
>> the rare sub-freezing days we get in Silicon Valley. The tires are fine.
>>
>> Is it best to ignore the light, or add air to compensate for the lower
>> pressure caused by the cold weather?
>
> I would check all of the tires, including the spare, with a tire pressure
> gauge and inflate to at least the pressures indicated in the owner's
> manual and on the driver's door or glove box door.
> --
>
> Ray O


How do you eliminate this silly thing entirely? Just replace valve stems
with normal ones?


From: SMS on
Ray O wrote:

> I would check all of the tires, including the spare, with a tire pressure
> gauge and inflate to at least the pressures indicated in the owner's manual
> and on the driver's door or glove box door.

All the tires were fine. The light went out by itself. They were all
29.5 to 30 psi, taken with a high quality dial type pressure gauge. It
says that they should be 32 psi, and I have no idea what the range is
before the light comes on. Maybe it's 10% and one of the tires was at 28
psi early this morning.

I recall renting a Chrysler minivan last year in Utah and when we were
up near Yellowstone in high elevation the TPMS light came on when there
was nothing wrong. I mentioned it when I returned the vehicle and they
said that it was a common occurrence in higher elevations (and they gave
me one day of the rental free just for telling them about the problem!).

It appears as if the TPMS systems don't correct for altitude or temperature.