Low pressure warning signals

The pressure warning points can be reconfigured through the OBD port - certainly for Peugeot. Unfortunately, in my experience it requires a main dealer and they will charge labour. According to another forum,  it’s possible they may refuse to change the set points from the manufacturer’s pre-set due to safety concerns and I can see the logic of that. My local Peugeot garage couldn’t do it despite having the Peugeot software.

This has been mentioned here before. I think it's bizarre that Peugeot have set their vehicles' tpms to a value that can't be altered by the end user. My Merc uses a tyre deflation monitoring system ie it uses the ABS sensors to look out for a wheel that's going faster that it should, but I can reset it to default at whatever pressure I want to.

The manufacturers spend 1000s of hours and millions of pounds validating the safest possible settings for the tyre combinations to stop premature wear, loss of control, and death.

This is to stop people who know better than them from running their vehicle not in accordance with the tyre pressures listed in the handbook and on the tyre pressure information panel.

The clue is in the word Warning, this means you have potentially made your vehicle unsafe to drive on the road and they are legally obliged to tell you this.

The OE sensors are far better than an aftermarket product, and no you can not remove them if they were supplied by the manufacturer (although this is physically possible), this would compromise the safety of the vehicle and invalidate your insurance and is an MOT failure. 

A rather patronising reply there Phishing. The base vehicle manufacture assumes that the vehicle is to be used commercially & set their tpms up accordingly. But not all these vehicles will be vans and so their tyre pressure don't need to be as high

Yes, agree but I work in vehicle validation and trust me when I tell you that there really are reasons over and above weight that determine the tyre pressures. The dynamics, handling, and braking of vehicles can be dramatically altered by the tyre pressures.

Sorry for the sarcastic reply but there really is good reason why fitment of TPMS was adopted in law for virtually all automotive regions, it saves lives. Van tyres are designed to run high pressures and should be inflated as instructed.

There is an argument (particularly with caravans) that the manufacturers could have a system of lower rated pressures dependent on the vehicle application. The cost of validation of the TPMS, braking and safety systems for all these different applications and the certification of all the options is just to costly. So you end up with the best safest option for all. 

I understand your reply. And having experienced driving with excessive tyre pressures in my car, the car was all over the place, I know exactly what you mean re handling, dynamics etc

But why can I reset the indirect ABS based system on my Merc to what ever pressure I want to when the vehicle above has had it pressure settings fixed with its TPMS?

I think the point is that the manufacturer sets the pressure for the base vehicle covering the maximum that it is designed to carry.  It cannot take in to account the unknown changes that are made to that vehicle when it is converted to something else, such as a motorhome.  As has been said many time the best way to establish suitable tyre pressures is to weigh the vehicle in operational trim and ask the tyre manufacturer for their recommendation. 

Your dealer may change the settings for you when you take it in for service our Fiat dealer did however they may also charge some labour for it depending on how friendly they are.  Even if you do get them changed it will not stop them inflating to what is on the sticker in the door frame when thy service it

They will tell you to look at the legally required sticker and use that information. They are not allowed to give you other information regardless of the use of the vehicle. 

MT, yes they will blow it up to the value on the sticker because they are legally obliged to do so.

I totally agree that the use of weight and pressure is a perfectly valid way to go about this but the vehicle is validated and homologated with the tyre pressure as per the sticker and you are obliged to maintain this.

There are tables that allow you to work out the best pressures based on the weight but this is just not a practical option. Quite frankly most people just dont give a damn, dont check their tyres, and would not take the time to work it out.