Tyre pressure direct measurement

[raulk89]

Hi

I know that this model has two ways to measure tyre pressure.
1. direct measurement (with tyre pressure sensor inside rims, can be added with extra cost)
2. indirect measurement (through ABS sensor, monitoring the rotation speed, included in standard)

My question would be, if I did not order this addition "direct measurement", and I would manage to find the VW original rims with tyre pressure sensors, then would it work in my passat also (showing direct tyre pressures in my dashboard)..?
Or are there some electronic components inside car also..? (meaning it will not work by default)


Raul

[gamichea]

You should not need to find some more rims. My Passat CC had direct measurement and when new tyres were fitted new sensors were fitted also so a tyre fitter should be able to do this for you at the cost of removing and refitting the tyres. A word of warning - these sensors have brass bodies rather than the more usual black rubber/plastic. Brass can react chemically with alloy wheels causing the sensors to seize in the wheels. I don't know but I'd guess there are no extra onboard components but you'd need a workshop to switch the ECU to monitor direct measurement instead of indirect measurement.

[YawnGumbo]

I didn't think the indirect measurement actually measured the pressure as a number. Doesn't it just measure that a tyre has suddenly lost pressure and report that through the car's computer with the warning light and indication of which tyre has the problem? The direct measurement actually displays the current pressure and change of pressure through the onboard computer display, so you'd have to make sure your car was programmed to display those readings as well.

[raulk89]

Correct.
From where did you realized that:
I didn't think the indirect measurement actually measured the pressure as a number.

[gamichea]

I didn't think the indirect measurement actually measured the pressure as a number. Doesn't it just measure that a tyre has suddenly lost pressure and report that through the car's computer with the warning light and indication of which tyre has the problem? .................

That's right. I don't think it needs to be a sudden loss just that loss has reached a certain level and that's all I need. If its serious I would expect to be sensitive enough to the car's behaviour. The TPMS on the CC was not as sophisticated display-wise as that on the B8. I didn't want it and it was not standard but the car arrived so equipped. The indirect system can false alarm. I experienced this soon after the B8 arrived. The car felt fine and checking the tyres by pushing against them at the services showed no significant issue and the warning went away on restart.