No handshake reply from master module md3[0] over Bluetooth

You cant just add G11 to the CAN bus and it works, it needs to be part of the application file loaded to the MD3 and this isn't possible with 2.63. G11 was not supported in that version. The other MD3 you describe that it works on it must be a later version of IQAN design, version 4 or above, and the module will be in the application file as an optional module (so there are no errors showing on the screen when its not plugged in). That's why it works on the other display.

Update IQAN design version and install an optional modem, then it will work. I believe there is also the ability to load into a empty screen using a G11 but this too may be on a later version above 2.63, IQAN team will be able to confirm.

See manual notes on compatibility for G11:

4 Product description
General
The IQAN-G11 is a Bluetooth dongle that works with the MD4, MD3, MC4, MC3 and
MC2 master modules in IQANdesign (4.00 or later) platform control systems.
The IQAN-G11 is designed to transmit wireless diagnostic data from the IQAN system
to a smartphone with IQANsync or a tablet with IQANrun.

Thanks! 

So I just need to update the software? What is the easiest way to update software without using Bluetooth?

Yes, update the software to version 4 or above and add G11 module to the diagnostics bus, this may be on bus A, B or C depending on the application currently in the module. You may have to bring it up to 4 in stages from version 2.63, so maybe bringing it up to version 3 first, then 4. If its a G11 that's not a permanent module on the system, configure it as 'ENABLED > NO' in the configuration on the right hand side. This just prevents errors if the system is powered without the module.

In terms of communication, there may be a USB wired into the screen, or go in on CAN on the diagnostics bus. Assuming of course its panel mounted and there is nearby hardware for this. If its a screen on its own it may be trial and error getting the right bus for CAN comms. Either method is easy and because the MD3 is a small screen there is not significant time savings for a particular method, they will both be relatively swift. Follow the instruction manual for MD3 for pinouts of all the options.

Thanks! I'll give it a try.