Auris tyre pressures

[Chriss27]

Hi I have had constant issues with the tpms since the cold weather arrived. Checked the tyres and they are all around 38ps but tpms remains on. I went to Toyota dealer a couple of months ago as thought had a puncture but said no that tyres were slightly under inflated and resolved it for a couple of weeks by adding more air but now Tpms came back on so Put a bit more air which sufficed for a couple of days but back on again. Dealer said it’s probs due to tyres now being over inflated and so recommended to put them all at 34ps. Done that but no difference and have done numerous tpms resets. Now my journey to work is not long and around 15 mind and know tyre pressures fall in cold weather so do you think tpms only on as tyres not had chance to warm up. Remember once had the issue but after around 30 mins tpms turned off. Thanks and any advice much appreciated.

[FROSTYBALLS]

See

 Tyre pressure monitoring systems can show warnings in cold weather due to air contraction and the effect on the radius of your wheels/tyres. Some tyre pressure monitoring systems judge differences in tyre pressures by comparing the radii of one's tyres.

Often corrected after running the car for a few minutes, when the tyres have warmed up, and the air in the tyres have expanded.

What pressures do your tyre pressure labels on the car recommend?

[16_Auris_HSD]

I've been ignoring mine since it came on when the proper cold kicked in last week. Another unnecessary and expensive answer to a question that nobody asked.

[FROSTYBALLS]

Unfortunately tyre pressure monitoring systems became compulsory on cars first registered from November 2014. So they may be an answer to a question no-one asked, but we have them, like them or not.

[Chriss27]

They recommend 34psi

[Devon Aygo]

To prevent the cold weather giving false warnings Toyota recommed:

During driving the inflation pressure increases due to tyre warm up. While parking mainly in winter, tyre pressure may decrease due to low ambient temperatures ( tyre pressure decreases by approximately 10 kPa ( 0.1 kgf/cm2, 1.5 psi ) for every 10℃ ( 50°F ) drop in the ambient temperature ). Therefore, the tyre pressure warning system is more likely to indicate a warning if the tyre pressures are not adjusted appropriately. If the daily temperature variation is large, add enough so that the tire pressures are suitable under cold conditions (*). As a result, unnecessary tire pressure warning operation should decrease.

* HINT : After initialization, add 10 kPa of pressure on top of specified value.

 

10 kpa is 1.5 psi so for ease of reading on the average tyre pressure guage say 2 psi, adjust your tyre pressures 2 psi below your desired pressure then reset the TPMS by switching ignition on > pressing and holding TPMS switch until it flashes then add the additional 2 psi to the tyres, this way when the tyre pressures drop due to the cold it should not trigger the TPMS warning

[16_Auris_HSD]

Isn't the warning also getting triggered when there's too much pressure?

[Devon Aygo]

No the sensor only reports a pressure below the threshold set when the TPMS button is pressed 

[16_Auris_HSD]

Oh, I didn't know that! That's a good idea then.

[Chriss27]

Thanks for the advice but this failed to work however a bit milder weather today and managed to reset tpms today without it immediately coming back on again. Cold weather it is then.

[tavy]

Then must be at least one pressure sensor damaged, or their Battery depleted. 
I inflate my wheels with nitrogen, in this way there's no difference in pressure between warm and cold weather.

[Chriss27]

Dealer now told me to take car in for reset for me to monitor. I wonder if this means they can reset tpms a different way rather than by the tpms reset button in glove compartment?