I jsut bought my 7th Mercedes in 37 years (still have a 1985 380 SL), a 2002 S430 with 67k and have a question about the tire pressure monitoring system. The tires do not currently have the valves that allow monitoring however the owners manual shows how to cycle through to see if there would be a reading. When I cycle through the dash information there is no reference to the tire pressure. Could this be from:

1. not having the sensor valves?

2. Could the system be turned off and therefore it would not show at all?

3. The system isn't actually installed in this model and year?

Any information will be greatly appreciated.

Thanks