Yes, you can make a 911 call even if you’re not connected to Wi-Fi and even if you don’t have a pass. 911 calls are free and always use cellular networks to help pinpoint your location.
In the United States Enhanced 911, E-911 or E911 is a system that links emergency callers with the appropriate public resources. Since wireless users are often mobile, some sort of enhancement is needed to 911 service that allows that location of the user to be known to the call receiver. E911 support is mandated by the U.S. Federal Communications Commission (FCC) for traditional mobile phone service and for certain VoIP service.
Click here to view the FCC guide to 911 calling.