Subaru Legacy BN/BS (2015-2019) Owners Manual: Activating and deactivating the alarm system

To change the setting of your vehicle's alarm system for activation or deactivation, do the following.

1.  Disarm the alarm system. Refer to "Disarming the system" .
2.  Sit in the driver's seat and shut all doors (and the rear gate (Outback)).
3.  Turn the ignition switch to the "ON" position.
4.  Hold down the REAR (UNLOCK) side of the driver's power door locking switch, open the driver's door within the following 1 second, and wait 10 seconds without releasing the switch. The setting will then be changed as follows:

If the system was previously activated: The odometer screen displays "ALOF" and the horn sounds twice, indicating that the system is now deactivated.

If the system was previously deactivated: The odometer screen displays "ALON" and the horn sounds once, indicating that the system is now activated.

NOTE You may have the above setting change done by your SUBARU dealer