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My question relates to the warranty status of a problem with the TPMS that started very early in the life of the car. The dealer has looked at it a few times but has adopted the position over the last year or more that they cannot do anything about it. The issue is that the problem is unresolved and the 3 year warranty period will end in September this year. Does the dealer have warranty obligations for issues they do not fix during the warranty period after the warranty expires? The background to the issue is that the TPMS has frequent false alarms - about every 500km over the last 4,000km. The false alarms nearly always take place on gravel or soon after leaving gravel. I travel on gravel frequently, often with 5 adults in the car and a full boot. The dealer has suggested the TPMS is too sensitive and that is something they cannot fix, but it may be they do not want to give me or try a later version of the TPMS "card". I believe there are later versions of this card. They have blamed me for running the tyres at 40psi (which I need to do when fully loaded according to the nameplate on the car) instead of their recommended 36psi (for light loadings). I have tried using 36psi for periods and the false alarms have not gone away. A tyre specialist also recommended 40psi saying tyre life would be better; I have followed this for the second set of tyres and after 18,000km of use the wear has been significantly less than the first set of tyres that were set 2 to 4 psi less (I measure the tread depths every few thousand kilometers and record the measurements in our computer). Further it appears from the fuel consumption computer that better economy is achieved at the higher tyre pressures. I believe I should be able to set the tyres to 40psi and that the TPMS is the problem, not me. I understand this is a minor fault in an otherwise very good car, but it could get worse with age and when "out of warranty". I am also very practised in the TPMS resetting procedure. We have the diesel limited version of the car with 225x55x19 tyres.

While I agree with the dealer insofar as the tyre pressures should be set to factory recommendations, this shouldn't cause a problem such as this.
Unfortunately, these systems are often affected by rough metal roads with pot holes and corregations. This system works by measuring different wheel rotations from the ABS sensors, so as you can appreciate, a sudden loss of traction on one wheel, as can be the case on a gravel road, will activate the system.
However, I believe Mazda may have some updates for this issue, so if you are getting no help from the dealer, you can contact Mazda and their technical support people will try to find a solution for you.

Thanks. It is very helpful to receive an independent expert view. The alarm is is loud and penetrating and my wife does not like it. I assume our passengers must wonder about it too. I will discuss it again with Mazda in the context of the warranty expiry and see if they are prepared to install an updated card.

Getting back to one question - do you have any comments on: "Does the dealer have warranty obligations for issues they do not fix during the warranty period after the warranty expires?"

In the case of an on-going problem that is reported during the warranty period but unable to be rectified, the dealer would have an obligation to rectify the problem even after the warranty has expired.