all fobs (3) stopped working, will not open doors horn is acctivated when I open door
 

2014 Chevy Equinox

a shop can check the fobs separately with a special tool but its unlikely that all 3 fobs went bad at the same time.
the module that operates the keyless entry is the remote door lock receiver. the first step is to check for codes in the module. a full function scan tool is required. a code reader cannot access this module.