Module :: Q2686G.
The firmware version is :: R74_00gg.Q2686G
Application OS :: 06.21
Boot loader version :: V08b0e
I am getting a good signal strength value[15-20] for AT+CSQ command, but the atd<phone number> is not making the calls.
When I checked the SIM registration value using AT+CREG? command, I got "2,2", which tells the SIM card is not registered with network.
Then how the signal strength is coming as such a good value range[15-20] ?
Sounds like your module is in Emergency Calls Only mode (+WIND: 7) - in that case, the CSQ result relates to the network providing the Emergency service.