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spathiphyllum | 10:10 Mon 08th Oct 2018 | Motoring
37 Answers
So on Saturday me and the Ms experienced a flat tyre. This was due to the tyre being pinched against a curb. The tyre was totally gashed and blew. Luckily we were about 1 metre away from our drive.

I jacked up the car, got the wheel off and put the spare on. We then proceed to go to a close by garage to get a new tyre on the vehicle.

When the tyre popped and on way to the garage with the spare tyre on, the Tyre pressure monitoring light was NOT on. We get the tyre changed, and on the way home the Tyre pressure monitoring light came on.

We checked the pressure all is OK, so is the garage we went to obliged to turn this light off for us? (need to plug into a computer) or is this potentially a fault of the computer system? Could it have been damaged when tyre blew?

I want to take it back to the garage but i don't want to be charged.

any advice?
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Spath @14.00 You need to trigger the re-calibration procedure then drive for 15 minutes or so and it will sort itself out. If you say what vehicle it is (as has been said a dozen times), someone can probably find the re-calibration procedure and tell you (or you can do it yourself). Look for TPMS recalibration [vehicle model and year] or reset TPMS [vehicle...
14:35 Mon 08th Oct 2018
You don't say what car you have and monitoring systems are different on different cars. My friend, who has a VW, tells me that their system works by comparing the rotation speed of wheels - a flat tyre will have a smaller radius than a properly inflated one, so will rotate faster than a properly inflated one; a new tyre will have a slightly larger radius than an old tyre, so will rotate more slowly than an old one. If the difference in speed is significant the warning will operate. Your system will work completely differently from this but it could just be that a reset is required - have a look in your handbook.
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So does it compare the front left to the front right?
You should be able to reset the TPM from a button on the dash.
Sorry, I don't know the full detail of operation or how sensitive to speed difference it is; if you give us full details of your car someone on here might know the answer.
When my trye pressure warning light stayed on after a change of tyre I was concerned; but it sorted itself out after driving for a bit.
TYRE
Question Author
What car do / did you have OG?
Hyundai i30
Question Author
Cheers
To reset the tyre warning on my car go to settings on steering wheel ( buttons on left hand side) go to settings then tyre reset hold down button for 3 seconds tyre warning light will disappear
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Banana what car do you have/had?
Mondeo
Watch this link it may help you

https://youtu.be/bBtep0x5y6E
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thank you
Have you checked to see that the tyre that wasn't changed is at the correct pressure?
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Yes, all pressures are OK
So what motor is it?
Tyre Pressure Monitoring Systems (TPMS) are useful, but can be a pain.

The i30 appears to use a so-called indirect TPMS (iTPMS). As indicated above, it compares the rolling speed of the four tyres front/back; left/right and diagonally. So each tyre is compared with the other three.

It’s simple, cheap, does not require any specific sensors… and inaccurate.

Imagine if you are going round a circular track. The inner wheels would travel less far than the outer ones, so the outer ones rotate more often, and so the iTPMS would indicate that the outer tyres are deflated.

Second, imagine a vandal has released the pressure in one of your tires overnight. One would hope that a driver would notice, but the iTPMS takes 10-15 minutes to detect that loss, due to the nature of the system.

A third issue is that in some countries, such as Germany, most drivers replace Summer tyres with Winter tyres in October and back again in April. Those tyres have different pressures and different rolling diameters compared to the Summer tyres.

Because the system does not have a direct pressure sensor, it needs to be calibrated. That involves driving for 10-15 minutes while the various sensors (in reality the ABS sensors on each wheel) detect the rotation of the wheels and tires and do their comparisons. You are supposed to inflate the tyres correctly before beginning the calibration.

In practice, when the low-pressure warning light comes on, drivers learned to hit the re-calibration button, and that made the warning light switch off – even though the tires might be in a dangerous condition.


Vehicle makers therefore made it more difficult for drivers to simply hit a re-calibration button, and that process now has to be done by a qualified personnel. Or there is a complex set of actions you need to take, so that you cannot reset the system without thinking about the consequences.

Whenever you adjust pressures in any one of the tyres, the iTPMS system needs to be re-calibrated.

Try the Hyundai owners club message boards to see if there is a solution on the boards. This is a very common problem.

The reason the system now tells you that there is a pressure alert is that the balance between the different tyres has changed. And that’s all it knows. It does not know the absolute pressure in each tyre.

I do not know if the garage will charge you for this. It is a safety feature, so in my opinion, they should not, but that opinion is not worth much where garages are concerned.

The alternative is to fit direct TPMS (dTPMS) systems, such as the following, on each tyre


http://www.fit2gotpms.com/michelin/ 

or these 

https://www.nonda.co/products/zus-smart-tire-safety-monitor

These have the advantage that they detect low pressure almost immediately, and can give an absolute read-out.

I have the Nonda system.

Another issue is that tyres lose pressure at a slow rate as air permeates through the sidewalls, so an iTPMS will not detect simultaneous pressure loss in all four tyres. A dTPMS. On the other hand will detect that loss.

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IJKLM so in short, your advice would be, make sure all tyres are to correct PSI, drive for 15 - 20 minutes. If light is still on try to reset it, if this process involves a lot of potential issues, is too complicated or requires professional tools, go to garage and suggest as it's a safety feature they resolve it, if they disagree just pay em and get it done
You're not listening, Spath. People are asking what make of car you have. If you supply this, someone will track down the 'reset' procedure. I don't know of any car which has to have the sensors r

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