Tyre pressure warning.

[Max_Headroom]

My tyre pressure warning light was on this morning i assumed because it was a lot colder than it has been of late, when i got into it tonight after work the light stayed off (18c sunny day) but it came on a few hours later when we took it out again to go to the shops, all the tyres looked ok so i took it to the garage where i found the rears were down to 28 psi  (should be 32) and the fronts were 32 psi (should be 33) i can only assume the previous owner had got the rear pressures wrong, the light has stayed out so i am hoping there is no slow puncture.

My main question is do you have to do the reset thing this guy suggests in the video or can you simply blow the tyres back up to recommended pressure and if the light stays out ignore it?

 

[MikeSh]

41 minutes ago, Max_Headroom said:

My main question is do you have to do the reset thing this guy suggests in the video or can you simply blow the tyres back up to recommended pressure and if the light stays out ignore it?

If this is the first time you've adjusted the pressures since getting the car then it's possible the trigger point has been mis-set previously. I'd recommend getting them to their correct cold pressures and doing a reset immediately (don't drive it as that will increase the pressures). It's not hard ... once you find the button.

[Derek.w]

Some cars MFG they reset if you put the tyre up to correct pressure others donot and you have to go through the reset procedure then one you have drive it that day or the next and it will then reset. If next day make sure your tyre is still inflated as you may have a slow puncture.

Its can also change by year/model.

[YarisHybrid2016]

The Gen.3 says to reset it "any time the pressures are changed". I used to do the tyres (when cold), then hit the reset button.

Procedure:

* Switch off the car
* Adjust tyre pressures
* Switch on the car
* After all the lights go out after starting, press and HOLD the TPMS reset button (under/to the right of the driving steering wheel column).
* Hold the button until the TPMS warning light starts slow blinking. Release when it starts blinking
* Wait 5 minutes
* Switch off the car
* Wait a few seconds
* Start the car, and start driving. The light should remain extinguished.

The tyres on the GR Sport (215 40/R18) seem to be quite sensitive. I last did the tyre pressures at +28 deg. C, and when I checked them today (+18 deg. C) they were about 1 psi too low. A bit more of a change than I was expecting (approx. 3 psi drop).

[Max_Headroom]

I cannot do them cold as I have to drive a couple of miles to the garage. 

[Bernard Foy]

1 hour ago, Max_Headroom said:

I cannot do them cold as I have to drive a couple of miles to the garage. 

They will still be cold enough to set. 

[TonyHSD]

You can buy a good quality pressure gauge and check before you drive off, have an air compressor and adjust pressure accordingly. 
This is the best way to do it and most accurate.

[Basil-BarryC]

16 minutes ago, TonyHSD said:

You can buy a good quality pressure gauge and check before you drive off, have an air compressor and adjust pressure accordingly. 
This is the best way to do it and most accurate.

That’s how I would set tyre pressures, purchase a good quality pressure gauge though as I have found that the internal gauges on cheap to moderate compressors can be very inaccurate.

[Max_Headroom]

1 hour ago, Bernard Foy said:

They will still be cold enough to set. 

The light didn't come on this morning so as it ruled out a slow puncture I have set the pressure using the hidden button

[Cyker]

If you inflate them back to what the car wants them to be, you don't need to reset it - The reset is just to tell the car "Oi! Car! Forget what it was set to before - These are the pressures I want the tyres to be now!"

I've noticed now and then with track videos, where they deflate the tyres before going on track, the tyre pressure warning light is on for the first few laps then goes out as the tyres heat up and their pressure increases  (And then comes back on as they cool again!)

 

 

[Derek.w]

12 hours ago, Max_Headroom said:

I cannot do them cold as I have to drive a couple of miles to the garage. 

Just wondering are you paying for your air all our local garages now charge you?.

[Max_Headroom]

19 minutes ago, Derek.w said:

Just wondering are you paying for your air all our local garages now charge you?.

Unfortunately yes £1:50 for 5 minutes. 

[Cyker]

Ahh, remember when they used to offer Free air!  

I keep a foot pump in my car at all times due to my propensity for picking up punctures so never needed to use a garage.

Worth picking one up during a sale! Even an electric one! (I don't like them because I found them unreliable - often breaking after a few uses - and also noisy and slow, but better than nothing!)

[Mojo1010]

53 minutes ago, Max_Headroom said:

Unfortunately yes £1:50 for 5 minutes. 

Buy a pump, this is what I got, store under driver's seat. Electric pump a very good one. Get yourself a digital pressure gauge too. 

[TonyHSD]

This is a good idea. Even a short drive can off set the pressure and cause wrong readings. 

[Mojo1010]

Same pump cheaper at £19.09. Had this for a few years, it's an excellent sturdy pump, double cylinder which pumps up quick. 

[Derek.w]

I am using a air inflator with its own power via a Battery pack.

[MikeSh]

The cheapest capital outlay option is to buy a decent pressure gauge. Then inflate a few psi high at the filling station and when at home, having let the tyres cool off {eg. overnight), use the gauge to drop them to the required pressure. Reset the TPMS if needed, and you're good to go.

From what I've seen digital gauges can be hit and miss, so I got a decent analogue gauge with a button to release pressure as needed. I use a Michelin footpump with a gauge to add air a tad high and then check/drop it with the separate gauge.

I have an electric pump too but it's really more time and effort than the foot pump, what with frigging round with the wires, etc, so I haven't used it in years.

[YarisHybrid2016]

I use Halfords cheap-and-cheerful double foot pump! Cost £5!!

As above - I over-inflate (slightly) using the foot pump, then set to the correct pressure by releasing air and using an accurate gauge.

[G L J]

15 hours ago, Max_Headroom said:

Unfortunately yes £1:50 for 5 minutes. 

That's inflation for you 🙂.

 

[Big_D]

I am lucky enough to have my own air compressor in my garage. I've had one for 20 odd years and still wonder how I managed without one. I use it for all sorts of things, including inflating the car tyres. I usually check tyre pressures once a month and use a digital tyre gauge. As @YarisHybrid2016, I also overinflate and then release air to set the correct pressure.