Check Each Vehicle Signal: Notes

Turn the ignition switch to "ON" with audio unit OFF. Next, while pressing the station preset "1" button, press and hold the station preset buttons in order, from "4" to "6" (or "6" to "4"), keep all four buttons pressed for 1.5 seconds.
NOTE: To exit the diagnostic mode, turn the ignition switch from ACC OFF to ON.
When «System Diagnostic Menu» is displayed, select {Confirmation/Adjustment} by SCROLL/TUNE dial, then press ENTER/SETTING key (SCROLL/TUNE dial).

Fig 1: Screen Display - Confirmation/Adjustment
Courtesy of SUBARU OF AMERICA, INC.
When «System.. > Confirmation/Adjustment» is displayed, select {Vehicle Signals} by SCROLL/TUNE dial, then press ENTER/SETTING key (SCROLL/TUNE dial).

Fig 2: Screen Display - Vehicle Signals
Courtesy of SUBARU OF AMERICA, INC.