WARNING: This page is about a different car, the 2014 Fiat 500c and 2014 Fiat 500. However, it is still accessible from the selected car via links, so may be relevant.
Possible Causes
(R3) LEFT CURTAIN SQUIB 1 LINE 1 CIRCUIT SHORTED TO THE (R1) LEFT CURTAIN SQUIB 1 LINE 2 CIRCUIT