Tyre Pressure Sensors

[Johndouglas]

How can you check whether or not a wheel sensor is working - other than letting some air out of the tyre? How can you tell whether a tyre fitter has damaged a sensor?

 

A few days ago I found my front tyre well down with no warning on the dash panel. The leak was obvious because a 1" Torx bolt was embedded through the tread. I've currently got the car in Spain so I took it to a small tyre depot in Malaga. They removed the tyre, vulcanized a patch to the inside of it, refitted it to the alloy and rebalanced the wheel - all for 10Euros.

[iannez]

if the sensor is damaged or removed it would show a fault. could they have been deactivated before you owned the car, have you ever seen them working.

[Johndouglas]

have you ever seen them working.

 

No I haven't. The car was 6months old when I got it - but why would anyone want the system deactivated?

 

I've often been puzzled by the fact that when I tow my caravan, I increase the pressure in the rear tyres. When I lower the pressure I would expect something to show on the dash panel. It never has!

[iannez]

its a cheap and easy fix mate. best way to check would be to fit the spare and give the car a run and see what happens. bmw have the best idea. they use the abs sensor to measure the rolling circumference of the tyre and when it falls below a set figure it puts the light on. dont know why they all dont use this method.

[Randombloke]

IIRC they only warn you when the pressure drops below 1.7 bar (ish). Usually the spare does not have a reporting valve.

 

iannez is right, if the sensor was damaged and giving warnings a dealer/indy could have quoted £125 for a new valve sensor, or £25-40 to connect up the laptop and deactivate the reporting valves.....

 

Also, the car needs to run for a small amount of time with a low tyre pressure?