A couple years back i had gotten rear ended and lost all function of the remote for my 2011 3GS. I HAVE CHANGED THE BATTERY. The car does start only if I use the remote up against the button, closing any door immediately notifies me that the remote isn't recognized even though its in the cupholder. Lock button doesn't work, alarm and the trunk button doesn't either. Although i can still open everything using the buttons on the doors. I'm unsure what's preventing me and what fix i could do. I've been stalking this forum for a while and saw how helpful this community is. hope someone can help. thanks in advance.

EDIT: for any future stalkers reference, i did some research. the culprit was the keyless entry antenna located middle of the rear body underneath the rear bumper, the replacement part number would be 89997-41010