TPMS reset not working

[WestcoastPete]

Hi

My 2008 Passat had a 120k major service recently at a reputable mechanic. The TPMS light is on now though (I can't remember exactly when it came on), and no matter how much I try to reset it it won't respond. I've tried with ignition on and engine not running, with engine running, holding for over a minute etc. The tyre pressures are all spot on and equal and it runs on the ABS anyway on this one.

I just took the button out (it's next to the gear shifter) and tested it, finding that there as a closed circuit on two of the pins when the button was pressed, which suggests to me that the button is fine.

Do any of you have any ideas on what's wrong? It's no big deal really, but orange lights do raise anxiety slightly.

Ta

[kamold]

You will have a sensor that's battery has died most likely.
If you do a scan of the car using VCDS, OBD11 etc this should confirm it.
Then you'll just need to get a new sensor installed in the tyre as the battery is not removable.

[WestcoastPete]

It doesn't have the sensors though. That's why I'm a bit flummoxed. This one works using the ABS sensors

[kamold]

2008 Passat has tpms receiver in the CCM.
It doesn't use tpms indirect in the abs module as far as I know.
Can check tomorrow but that's the setup in the b6 r36 so don't think it's different in other b6s.

[kamold]

Yep just checked the wiring diagram.
from 2005 Passat B6 has TPMS direct.
Doesn't switch to indirect until B7 Passat where you had the option of TPMS direct with individual tyre pressure display (which I've retrofitted in mine) or TPMS indirect through the ABS module.

[Passat my07]

In the 2007 handbook it has instructions for both types. The abs style one has "set" on the console button and is called tyre monitor display.
The tyre pressure monitoring system just has a picture of a flat tyre on the console button.

[kamold]

And which one do you have?

[Passat my07]

Our current 07 v6 has the one with the stem sensors but I'm 90% sure our old 07 fsi turbo had the abs style?

[WestcoastPete]

Yep just checked the wiring diagram.
from 2005 Passat B6 has TPMS direct.
Doesn't switch to indirect until B7 Passat where you had the option of TPMS direct with individual tyre pressure display (which I've retrofitted in mine) or TPMS indirect through the ABS module.

I'm surprised by this. I've investigated this before (not long after I got the car and the light came on), and I'm pretty convinced this '08 tdi doesn't have direct TPMS. It certainly doesn't appear to have special valves. They just look like standard valves.

Hmmmm

[kamold]

I'm surprised by this. I've investigated this before (not long after I got the car and the light came on), and I'm pretty convinced this '08 tdi doesn't have direct TPMS. It certainly doesn't appear to have special valves. They just look like standard valves.

Hmmmm

Unless you look inside the tyre you can't tell the difference.
The sensor is behind the stem. (Stem is part of it but looks no different externally to a regular valve stem)