salukidude

iTrader: (3)

So I start up the car yesterday and I get the low tire pressure display. Of course it doesn't tell you which tire, so I get out and check all four. They looked good. I drove to a nearby gas station and checked the pressures. The right front was about 26-27 psi, which is low but not that bad. The other three were at about 29-30 psi. I filled each up to about 31 psi. I got back in, started it up, and the display was still on. I said F it and hauled *** around a corner and the warning went away. Was one of the sensors just loose or something. Also, it was raining (it never rains here) and was a bitterly cold 45F so I wonder if that is a factor. Thanks!

02-Lancer-Es

iTrader: (21)

On my Gf's 08 Lancer the warning comes on randomly and go's away randomly also , i notice it does it more when its colder .

brads09lancerGT

iTrader: (7)

I put my 16" winters/steels on my car on tues and I didn't put the tpms in them. My tire pressure sensor didn't come on till this morning. I drove it for approx 260kms before the stupid warning light came on That is really reassuring to know that the light takes days to come on with no sensors in the tires but keeps coming on whenever it feels like it when your tires are almost fully inflated.

John83

iTrader: (1)

your tires are cold and when you drive around, tires warm up, air expands, pressure goes up, light goes off. this is common at this time of year when it starts getting colder, your tires loose pressure because of this.

also, if you put different tires/wheels on, it takes like 3 start-ups or a certain distance and THEN the light goes on.

/thread.

salukidude

iTrader: (3)

I live in LA. It's no less then 45 degrees here in late December. Are you telling me Mitsu cannot calibrate the sensors to account for cold(er) temperatures? I mean wtf do people in the Northeast do; drive around with the tire pressure warning on all winter???

Joe's Evo X

iTrader: (4)

ummm when its cold the pressure in your tires are low. Fill the tires up. When its hot let the pressure out. Case closed.

SpaceMonkeyAndy

It isn't a question of calibration. The tire pressure monitoring sensor monitors pressure in the tire - no more. When it is colder, the density of the air increases, and the pressure decreases. Remember the ideal gas law (PV = nRT); if temperature is decreased, while volume remains constant, number moles remains constant, and the gas constant... remains constant, pressure must decrease as well. The next logical step would be to monitor temperature as well to estimate what the current pressure will be when in an approximately steady state. However, this adds extra complexity and problems.

jebus27

iTrader: (8)

Just refill them with nitrogen..... the change in pressure is very minimal compared to regular air, during high and low temperatures... saves gas too

salukidude

iTrader: (3)

WTF people, I understand thermal dynamics including pv=nrt. Once again, I live in LA. It was 45 degrees Farenheit when the tire pressure warning showed up. Why aren't people from much colder climates complaining of this? Unless someone with a similar situation has something to offer, please keep your post count to a minimum. Thanks!

SpaceMonkeyAndy

Being difficult isn't a good way to get answers, but I will give you a pass on this one. Most likely the system operates in such a way that it can be triggered by absolute pressure as well as relative pressure. If the pressure of any tire drops below a preset limit the indicator will come on, signally a critically low tire from a a leak or blowout. Additionally, the sensor will probably be activated by a relative low condition based on the pressure difference between tires. You said that three of the tires were at ~30 psi, while one was at ~26 psi. All wheel drive systems are very particular about rolling radius. A lower pressure tire will wear more quickly as well as roll differently compared to a filled tire. Thus, the TPMS is most likely trying to protect the differentials in your car. As far as it not going off immediately, the system probably requires some limited time to ensure proper function and recalibration of the sensor. I had a tire blowout (grrrr trucks that shed debri into my car) and the TPMS sensor didn't go off for about 10 minutes (on my subaru).

Is that helpful?

628

iTrader: (1)

I live in LA as well...and it's the same thing.

I have to get air at least once a week now because of the weather.

People in colder climates aren't complaining because they simply understand the concept of what's going on here and know to fill up their tires with air..

And yeah, the display will still be lit up after you fill up with air and start driving...takes about half a mile for it to detect the change.

Enjoy your Evo...while keeping your post count to a minimum.

KPerez

Northeast experience: Been down here in the 20's F, never touched the tires since delivery and no TSP light. So what you guys are seeing is not related to low temp. but perhaps pressure differences as suggested earlier.

Later, Ken

murlo26

iTrader: (9)

It finally got above 10 degrees here, was negatives for like a week or so. I filled up once this week, but the light would come on normally on startup and upon driving it would go off due to the tires warming up a bit. Eventually it was low enough and cold enough out where it didn't matter and I had to fill up with air finally.

And yes, its temperature related, its not rocket science man. It happens every year and thats why people always end up in ditches and have ****ty traction because they don't know to keep their tires inflated for snow/ice traction. It is a little surprising that it came on at 45 degrees, but it's most likely because you were under inflated to begin with, my light comes on at around 25-26psi. If you understand the equation, i don't see why you still have a question.

melnor

Check your spare, it requires 60psi. Mine was at 40 psi when my tire pressure warning came on. Filled it back up to 60 and never saw the warning again.

John83

iTrader: (1)

i guess this might be a surprise if this is someones first car with TPMS even though this is nothing new when it comes to tire pressure.