Strange Question - Car Tyre Pressure Sensors

[ukdude13]

This is a bit of a random question, and I'm not really sure where to post it, but I thought it might interest some of you.

My dads car, like most newer cars, has a tyre pressure monitoring system, however hes been told by lots of different people they are more hassle then they are worth as the warning bleep goes off all the time because tyre pressures are always changing slightly. He's been told I can't turn the aystem off because the manufacturers say it's a safety feature.

However when he gave his father in law a lift the other day he noticed the warning did not come on, but returned after my grandad had left the car. The only thing I could think that would cause this is my grandad a pacemaker!

He was told that it gives off electromagnetic radiation, and therefore may set off shop security scanners.

Does anyone know if this is possible or likely and if so does anyone no any way I could test this, other then getting my grandad to sit in the car all the time.

Thanks for you help

[barry99705]

If the pressure sensors are going off all the time, he needs to get it checked. The only time the ones in our Juke go off is in the fall when it starts getting colder and the pressure drops in the tires.

Also, pretty sure his pacemaker isn't going to do crap to the sensor signals.

[cooper]

I honestly don't understand how the pressure thing in my car works. It flicked on at some point last year so I dutifully inflated the tires a bit (and it did need it) but then the pressure warning didn't go off. I had to manually tell the console that the tire pressure had been set appropriately again. The guy at the dealership gave me a sufficiently vague explanation for it that it's already escaped my memory, but yeah. Weird shit.

[digip]

If it's going on, most likely it's because its low. Inspect the tire tread and all 4 tires pressure. Check the actual tire pressure manually with an external gauge(all 4 of them) and not from the gas station pump gauges which are not accurate(although some new ones use digital displays, I carry a hand gauge in my glove box and they are almost always off at the pump), as they can be faulty.

There are two main types of sensors. Direct and indirect, which if you have the one that works off the tire rotation, tread size and anti-lock brakes, vs the direct only sensors, you may find it go on more often. The indirect sensors measure tire height during rotation in addition to pressure, so if your tires tread is below a certain area or over inflated, you may find that as time goes on, it will go off more often, especially when cold and lower tire pressure, which in a way, may also help gauge how well your tires are lasting since tread is important to safety as much as pressure. Just know that in most cases, it's a warning to check all 4 tires pressure and tread count, and most likely not going to be an issue if you keep an eye on the tires.

When in doubt, check everything, and if it doesn't go off after adding more air or deflating such, take it in. Just remember, too much air, can actually set it off as well, so if you like a firm tire, you may be setting it off and eating more tire tread over time(although it saves a few mpg on gas, I used to do this in my old truck to gain a bit of gas mileage, it does wear out the tire quicker).

edit:

Found this, explains it even better. Working at a car dealership, I was under the impression both types had sensors in the tires, but I guess not :

http://auto.howstuffworks.com/car-driving-safety/safety-regulatory-devices/tire-pressure-monitoring-systems1.htm

@cooper, looks like you may have the ones without the in tire sensor that need to be reset after each tire inflation?

Edited July 29, 2015 by digip

[cooper]

Hey, nice one! Thanks for that.