I have the 2GIG GC3 and the 2GIG-SP1-GC3. Both have the 3.1.2 firmware. I cannot get the 2GIG-IMAGE2 to pair using the 9999 equipment code or the code the firmware provides. It will not find the serial # on learn. The image 2 device has reset repeatedly during the process.
Happy to help! To verify: do you have the necessary 900mhz Transceiver for the Image Sensor installed on your panel? You can find the transceiver here. If you purchased equipment from suretyDIY you can find this requirement listed on the product page.
The Image Sensor uses 900 mhz RF transmissions and the alarm panel does not have a 900 mhz radio by default. I believe 2GIG does this to lower the cost of the primary panel, as Image sensors are only used by a portion of 2GIG panel users.