VW Passat 2012 TPMS light on

[muqeet]

My passat had an incident where Battery acid leaked and it damaged ABS Module, various light on dashboard switched on. Auto hold, cruise control, tpms all stopped working. I found a used ABS module and got it replaced, also had to replace a sensor close to one of rear tyres that works with ABS module to send speed data, etc.

All went well, all features started working as expected except TPMS. The guy who replaced ABS Module said there would be a sensor in valve that might be damaged and tyre shop can figure out which one needs to replaced. Went to tyre shop and they said there is no sensor, the pressure is gauged through rotation and speed of tyres and that I should consult with auto electrician...

Any help would be greatly appreciated.

 

[DPG]

My passat had an incident where Battery acid leaked and it damaged ABS Module, various light on dashboard switched on. Auto hold, cruise control, tpms all stopped working. I found a used ABS module and got it replaced, also had to replace a sensor close to one of rear tyres that works with ABS module to send speed data, etc.

All went well, all features started working as expected except TPMS. The guy who replaced ABS Module said there would be a sensor in valve that might be damaged and tyre shop can figure out which one needs to replaced. Went to tyre shop and they said there is no sensor, the pressure is gauged through rotation and speed of tyres and that I should consult with auto electrician...

Any help would be greatly appreciated.

Surely it would still need some sort of sensor on the wheel somewhere though?

 

[UNG]

The valve is part of the TPMS module they have a battery in them that lasts 5 - 10 years

 

[DPG]

The valve is part of the TPMS module they have a battery in them that lasts 5 - 10 years

That's what I mean, but he says the tyre place said not. You'd think they would know, bearing in mind they specialise in tyres.

 

[James]

not sure on the age or model of the pasat but this is generaly what the TPMS sensors look like.
A decent tyre garage should be able to diagnose and repair this type of fault.
often the car needs programming to accept the new sensors.

p.s. I presume you have checked the tyre pressures are all ok? including the spare tyre.

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[muqeet]

The part below was faulty and replaced as part of the ABS Module replacement. The mechanic told me that he is not getting wheel speed reading from that sensor initially, replacing that worked.

2005-2022 Volkswagen Rear Speed Sensor WHT-003-858 | VW Parts Online

2005-2022 Volkswagen part # WHT-003-858 - Rear Speed Sensor

www.vwpartsnowonline.com

I read somehwere (cant find that link atm). That this same sensor also works with TPMS and I believe thats why tyre shop said there no valve sensors in my car. Pressure is calculated from rolling diameter or movement of tyres etc.

 

[DPG]

The part below was faulty and replaced as part of the ABS Module replacement. The mechanic told me that he is not getting wheel speed reading from that sensor initially, replacing that worked.

2005-2022 Volkswagen Rear Speed Sensor WHT-003-858 | VW Parts Online

2005-2022 Volkswagen part # WHT-003-858 - Rear Speed Sensor

www.vwpartsnowonline.com

I read somehwere (cant find that link atm). That this same sensor also works with TPMS and I believe thats why tyre shop said there no valve sensors in my car. Pressure is calculated from rolling diameter or movement of tyres etc.

Interesting. I find it hard to believe an accurate tyre pressure can be obtained using speed of rotation, but maybe I'm wrong.

 

[UNG]

If the TPMS uses wheel speed to gauge tyre pressure how is the compensation set for tyre wear given that the diameter of the tyre will reduce by 10mm or more over it's lifespan

 

[plugsandsparks]

cars of that age inc, VW, Audi, BMW use calculated rolling diameter to detect a flat tyre. They can typically throw a fault when changing tyres for new or putting winters on. There is a reset button when this occurs which enables the TPMS function to re-calculate the new setup. In the Polo for example the button is in the glove box, on the BMWs it is often in the menu off the info screen. It is possible it is in the glovebox of the Passat and needs to be pressed for a minimum of a few seconds.

 

[muqeet]

Hmm, I read about reset button online. My passat dont have it. Does it mean tpms in my car is not on rolling diameter?

 

[plugsandsparks]

Only come across 2 types of TPMS, rolling diameter using wheel sensors through ABS module and individual tyre pressure sensors on the wheels (rather inside the wheel rims), you have ruled out pressure sensors via the tyre shop so it only leaves the former. If your car actually can display the actual tyre pressure, i.e. 34psi etc, then its certainly the latter. You could try calling the VW dealer, get through to parts and give them your VIN and ask them .

 

[brianmoooore]

Alternatively, go onto the website of a parts supplier, such as Autodoc, where you enter your reg to identify your vehicle. If they offer in tyre pressure sensors for it, then that's what you have.

 

[muqeet]

Only come across 2 types of TPMS, rolling diameter using wheel sensors through ABS module and individual tyre pressure sensors on the wheels (rather inside the wheel rims), you have ruled out pressure sensors via the tyre shop so it only leaves the former. If your car actually can display the actual tyre pressure, i.e. 34psi etc, then its certainly the latter. You could try calling the VW dealer, get through to parts and give them your VIN and ask them .

IT never displayed me the actual tyre pressure, which is a good indication that there are no individual sensors in wheel.

In this scenario what options do I have simply consult with an auto electrician?