Tyre pressure sensors - again

[Shoppinit]

Ah so there must be a way to check each one.

Anyway, I'll get my wheels back tomorrow so I'll pist whether the £75 ones work or not!!!! The website quoted an OEM part number but I havent seen one apart from the ones I bought so cant comment on whether it was the same or not.

You should get an error like this:
01467 - Front Left Tire Pressure Sensor (G222)
53-00 - Supply Voltage Too Low

If not, then you'll have to use the measuring blocks to try and identify individual sensors. This from ross-tech wiki:

raise or lower the pressure in one tire at a time and double check the Measuring Value Blocks (MVB) 001-012 (and 016) for changes. If you find one which does not change after raising or lowering the Pressure, you have most likely found the faulty Sensor.

Note: It may take up to 2 minutes before a pressure change is detected by the control module and displayed in the Measuring Value Block (MVB). To locate the individual Wheels it helps to make a note the Sensor Identification Number.

[jd_hants]

Right, got the wheels back and on the car last night.

Reset the TPMS. Drove to work, 25 miles, about an hour. So far so good. Usually within 10 mins the typre pressure warning will come on. I will leave the car running when i get home and let some pressure out of one and wait and see what happens. I think I read somewhere it takes a few minutes to register? Anyone know by how much the pressure needs to drop? Is it by a set amount of PSI or down to a % of the original set pressure. Also, is it better to set the pressures when the tyres are cold or hot?

[Shoppinit]

Sounds promising! The upper and lower limits are set using the vagcom. If you've got one, you'll be able to see.

Alternatively, when the rim is touching the ground, your sensor should have gone off

[grizz]

I stripped down a sensor today..


I think it's fare to say the battery can't be removed. The unit is assembled & them fully sealed with a rubber coating.

There is no way to remove the circuit board that sits over the battery with out damaging it.

[MarkusRS6]

maybe a stupid question, but where is this sensor located?
Also when I get new tyres, does the sensor need special attention of some kind?

[Shoppinit]

It's inside the rim. It hangs off the valve stem inside.



No special attention. Just make sure they don't break it. You can change the valve cores, no problem. They are standard.

[MarkusRS6]

great man, that couldn't be more clear

[Shoppinit]

[jd_hants]

still no faults reported By now I would have got errors on the DIS. so, APPEARS to be working.

didnt get a chance to test by letting the tyre down. droping car at camberley later so will stop off at a garage and do a test.

[philroach]

always set tyre pressures when cold , as air expands when hot , which will give false readings , now we can all start asking each other what pressures to set at !!!!
phil

[jd_hants]

ok. its official. the TPMS sensors from the place I quoted on the previous page definately work!!!! one by one i let air out of each tyre and within 15 seconds each one showed up as a fault in the dis. pumped up and fault gone

so £87 + VAT per wheel for sensor and valve.

[Shoppinit]

But surely you most of the time when you're driving your tyres will be hot - so wouldn't you want to learn the nominal the pressures when hot?

[Shoppinit]

ok. its official. the TPMS sensors from the place I quoted on the previous page definately work!!!!

Result!

Nice one, I suspect there'll be plenty of us following in your footsteps.

[jd_hants]

And no setup routine/learning. I just put the wheels on and clicked the 'store pressures' menu option. ive no idea whether you need to do anything else if you have sensors already. when i got my car there were no sensors fitted so it was just switched off in the menu. so if just replacing one - maybe disable the system. change the sensor. put the wheel back and then reenable it. just changing the sensor without disabling/enabling may cock it up. i might be wrong. just a thought.

[MalcolmSu]

But surely you most of the time when you're driving your tyres will be hot - so wouldn't you want to learn the nominal the pressures when hot?

but do they not only alarm when there's a pressure loss of more than 3psi in which case when you parked up they'd alarm when cold? You want to store the pressures (40psi all round here) when cold...