2014 Skoda Yeti 4x4 with tyre pressure monitor system.

Is it direct, or indirect? ie Is there a sensor mounted in each wheel as part of the valve?

If it does have these sensors, and I buy new rims that don't have the sensors, does the TPMS have to be deactivated, and how is it done?

It's indirect. 

 

It's done by monitoring the rotating speed of each wheel via the ABS sensors.

It's indirect. 

 

It's done by monitoring the rotating speed of each wheel via the ABS sensors.

 

When I change from 17"Alloys  to 16" Steels in winter will this affect the sensors ?

If all tyres are correctly inflated just hold the TPMS button to reset it to your new wheels.
But as it looks for a difference in rotation speed between wheels it will probably not even need a reset.

When I change from 17"Alloys  to 16" Steels in winter will this affect the sensors ?

Nope.... just remember to reset via the TPMS button.

Nope.... just remember to reset via the TPMS button.

Hold the button until it beeps, result!

 

Fred