Tyre Pressure Monitoring System

Yes it can, if more then one sensor transmits its data at the same time then
they can interfere with each other assuming the same fequency is used by both
systems. However the the sensors have different different transmit intervals programmed
into them to avoid the above so if two or more should transmit their data at the same time
when the next transmission occurs they should be a different times.

The only time this might be an issue is with a fast leak but the chances of it happening when two
sensor decide to send at the same time would be remote but I have seen instances with mine where
a couple of sensors first transmission after them waking up has been missed but subsequent
transmissions are ok most likely due to the above.

Thank you for the information and for your prompt reply.

I bought a Masten TPMS and I wanted a combination of internal and external sensors, however the manufacturer told me that the monitors would only do one or the other as they ran off different frequencies. Also, some of the monitors were limited to how many wheels they could see. I chose external as it was easier to swap them around to a spare wheel if I needed to.
In your case it probably comes down to what frequency your internal sensors are and I couldn’t see why you couldn’t have a completely separate aftermarket monitor for external sensors if they are a different frequency. Maybe if you know someone with external TPMS you could borrow for a few hours and see what happens.

What is the reasoning to wanting two monitors on the same tyre?