I have been using my Sony Ericsson Satio for my G37 since i bought the car. Initially there was no issue but recently had started to act up.

The phone would connect to the car via bluetooth normally. However, when i want to make a call (initiated either through the phone itself or the car's steering phone button/touchscreen)..the system acted as if there was no call being made (no call icon/display on the Nav screen and no sound from car speaker) and thus forcing me to use the phone itself instead of the Hand's Free feature..

This also happens when answering a call, again, either through the phone itself or the car's steering phone button/touchscreen...

Also..additional info..this issue only occurs sometime though (like 3 out of 10)..

Any advice on resolving this issue??

 

Not sure, I use my iPhone and it works fine, I'd say take it to the dealership
<img src=http://i105.photobucket.com/albums/m216/raul0434/signatures/ryanSIG.jpg>

 

an electrical issue like this could almost be anything. You'd have to take it in to see if its covered by warranty and if can be resolved.