To set up vehicle alerts, you can create alert plans that apply to:
All vehicles: Vehicles > Vehicle Manager > General Settings > Alerting
All fleets: Vehicles > Fleet Manager > General Settings > Alerting
An individual fleet: Vehicles > Fleet Manager > selected fleet > Edit Fleet > Alerting
An individual vehicle: Vehicles > Vehicle Manager > selected vehicle > Edit Vehicle > Alerting
Vehicles inherit all alerts from all plans they're associated with. Regardless of how you access Alerting, the process for specifying alerts is the same. See Set up alerts.