No Pressure Data?

Hi all, 

Just bought a new MK3i with 2x T2 transmitters. 

I connected it at the dive watch and it showed connected properly, made all the noises etc. but it showed 0 psi despite being connected to the tank. This was true for both transmitters. 

I have a diving trip next week and I'm concerned. Do they only active and start showing pressure data once I start a dive and get into the water. Are these broken?