[jmr986]

When it gets cold the TPM gives me a low pressure warning. I used to check it but now I just ignore it. It only got to the low 50's F and it went off. Checked the pressures, 26.5 all around. Topped it off to 30 all around to see if that helps. I see max is 35. Don't want to go there. What's number seems to work best for everyone.

[SonicEndeavor]

Set the pressure to whatever it says in the drivers side door jamb when the tires are cold. Mine is 35psi fronts, 39psi rears.

[Gilgorm]

The TPMS measures changes in psi. It doesn't matter what the starting point is. It only measures changes compared to that starting point.
BTW, you should be setting the pressures to what is in either your manual or on your door jamb.
26.5 is very low and there should be a variance front to rear.
My door jamb recommended pressure is 35 front and 39 rear. These are not maximum but recommended pressures.
Your car ride should change radically (for the better) with these pressures.
At 26.5 the tires should be squirming around and in fact feel flat.
The pressure should only be checked when the tires are cold. The TPMS should be reset after any pressure change.
Hope this helps.

[SonicEndeavor]

Originally Posted by Gilgorm

The TPMS measures changes in psi. It doesn't matter what the starting point is. It only measures changes compared to that starting point.

Is that how the indirect systems in Canada work? The OP is in the US and our TPMS (direct) systems measure actual tire pressure and temperature at each tire in real time.

[ezaircon4jc]

Originally Posted by SonicEndeavor

Is that how the indirect systems in Canada work? The OP is in the US and our TPMS (direct) systems measure actual tire pressure and temperature at each tire in real time.

I coded my 535i to display the actual temp and pressure yet all I get is --ºF and --PSI. I do have the metal stems.....

[lsturbointeg]

Funny someone posted this as I'm having the same issues. Every morning I have to reset it. I thought cause I read some where that maybe the batteries on these TPMS are going since my car is a 2011? so now the seasons are getting a bit colder the TPMS are pretty much useless?

[Teddylongtooth]

Originally Posted by ezaircon4jc

I coded my 535i to display the actual temp and pressure yet all I get is --ºF and --PSI. I do have the metal stems.....

What are you talking about Willis? Do metal stems cause the tpms to not work correct? My tpms sensors don't work , I ordered the beru tpms for my forge stars and they learned into the car on the way to the tire store, and then after I had them put in they won't learn in anymore. And yes they learned in sitting in the box on the front seat while driving to the wheel shop. I don't get it, if I don't figure out why soon I'm going to swap the sensors from my stock wheels. If I do that I have to put my wheels at risk by the tire jockeys again, if they scratch em I'll go ape shit!

[Teddylongtooth]

Originally Posted by lsturbointeg

Funny someone posted this as I'm having the same issues. Every morning I have to reset it. I thought cause I read some where that maybe the batteries on these TPMS are going since my car is a 2011? so now the seasons are getting a bit colder the TPMS are pretty much useless?

No man, the tpms should last atleast 10 years, the reason your getting a low tire is when it's gets cold at night the air pressure drops. Cold air condenses and hot air expands which is why we get a pressure drop in the morning and not during the day, how cold does it get at night where you live? Its science

[lsturbointeg]

Originally Posted by Teddylongtooth

No man, the tpms should last atleast 10 years, the reason your getting a low tire is when it's gets cold at night the air pressure drops. Cold air condenses and hot air expands which is why we get a pressure drop in the morning and not during the day, how cold does it get at night where you live? Its science

It got down to about 37 degrees on the way home last night and even the low outside temperature warning came on. I wonder if nitrogen will work as most people now have been doing that instead of just air?

[peter91118]

Originally Posted by lsturbointeg

It got down to about 37 degrees on the way home last night and even the low outside temperature warning came on. I wonder if nitrogen will work as most people now have been doing that instead of just air?

+1 for nitrogen

[r33_RGSport]

TPMS battery life is 10 years on the shelf, but once installed and pressurized, the battery life is 4-5 years.
It has tolerance 25%. So unless it gets really cold very much, then it will give you a low tire pressure message.
The best solution is to run nitrogen or check your tire pressure frequently and reset the tpms to memorize the new pressure.
That way it will only give you warning after it dropped 25%.

[DDD31]

Damn you Gay-Lussac's Law...

[lsturbointeg]

Originally Posted by r33_RGSport

TPMS battery life is 10 years on the shelf, but once installed and pressurized, the battery life is 4-5 years.
It has tolerance 25%. So unless it gets really cold very much, then it will give you a low tire pressure message.
The best solution is to run nitrogen or check your tire pressure frequently and reset the tpms to memorize the new pressure.
That way it will only give you warning after it dropped 25%.

Appreciate the info!

[ezaircon4jc]

Originally Posted by Teddylongtooth

What are you talking about Willis? Do metal stems cause the tpms to not work correct? My tpms sensors don't work , I ordered the beru tpms for my forge stars and they learned into the car on the way to the tire store, and then after I had them put in they won't learn in anymore. And yes they learned in sitting in the box on the front seat while driving to the wheel shop. I don't get it, if I don't figure out why soon I'm going to swap the sensors from my stock wheels. If I do that I have to put my wheels at risk by the tire jockeys again, if they scratch em I'll go ape shit!

Metal stems are supposed to indicate a TPMS that will read the pressure and temperature.

Originally Posted by lsturbointeg

It got down to about 37 degrees on the way home last night and even the low outside temperature warning came on. I wonder if nitrogen will work as most people now have been doing that instead of just air?

Air is 78% nitrogen...... Does the other 22% make that much of a difference? Just asking....

[Gilgorm]

Originally Posted by SonicEndeavor

Is that how the indirect systems in Canada work? The OP is in the US and our TPMS (direct) systems measure actual tire pressure and temperature at each tire in real time.

Sonic,
You are of course correct that the TPMS measures actual pressure and temp BUT it will only give a low pressure warning if the actual pressure is lower by ??? % compared to the reset value.
i.e. if the TPMS was reset when the tire was at 39 psi and the reading subsequently fell to (say 25% less) 29 psi then the warning would let the driver know the tire pressure was low.
I had TPMS on an E60.

All Canadian F10s do NOT have TPMS but have FTM (Flat Tire Monitor) which is a useless, cheaper system that only tells the driver when the tire is critically under-inflated or almost 0 psi. FTM is particularly ineffective with run-flats since they don't change their shape as radically as a 'normal' tire.
FTM must also be reset when tire pressures are changed.
Thanks for allowing me to clarify.

[peter91118]

Originally Posted by ezaircon4jc

Air is 78% nitrogen...... Does the other 22% make that much of a difference? Just asking....

This is a good read.

[ezaircon4jc]

Originally Posted by peter91118

This is a good read.

Yes it is...

The other issue is checking the pressure when cold; which means driving less than, IIRC, 2 miles or waiting at least 3 hours. Kind of hard to do anywhere except home...

[cityjohn]

Hats off to any motorist who can keep each of four wheels at 36.6 psi

[lsturbointeg]

So here's what mine looks like...no temp, no psi...just yellow = boring! Is that a coding u guys do to get the additional info displayed?

[ezaircon4jc]

Originally Posted by lsturbointeg

So here's what mine looks like...no temp, no psi...just yellow = boring! Is that a coding u guys do to get the additional info displayed?

Yes, but I am one of the few (according to the coding forum) that the temp and pressure doesn't register....

[Alcenos]

Originally Posted by DDD31

Damn you Gay-Lussac's Law...

PV=nRT

[HighlandPete]

Originally Posted by lsturbointeg

Funny someone posted this as I'm having the same issues. Every morning I have to reset it. I thought cause I read some where that maybe the batteries on these TPMS are going since my car is a 2011? so now the seasons are getting a bit colder the TPMS are pretty much useless?

Something must be wrong if a reset doesn't cope with a few degrees change in ambient temperature during the day.