1. Disconnect the negative battery cable..
2. Remove the sunvisor..
3. Verify that the continuity between the vanity mirror illumination terminals is as indicated in the table.

If not as indicated in the table, inspect the bulb. If there is no malfunction, replace the sunvisor.

Vanity Mirror Illumination Bulb Removal/Installation
Power Outer Mirror Switch InspectionAutomatic Transaxle Fluid (ATF) Inspection [Fw6 A EL]
CAUTION:
If the ATF level is not within the specification or ATF is not adhering to
the dipstick after warming up the engine, do not drive the vehicle. Otherwise,
the transaxle could be damaged.
ATF Level Inspection
1. Remove aerodynamic undercover No.2..
2. Remove the dipstic ...
Sunlight/Temperature Sensor
The climate control system measures
inside and outside temperatures, and
sunlight. It then sets temperatures inside
the passenger compartment accordingly.
CAUTION
Do not obstruct either sensor,
otherwise the climate control system
will not operate properly.
...
Headlight switch
In the Subaru Solterra, the headlight system can be controlled either
manually or automatically, offering flexibility and intelligent adaptation to changing
driving conditions.
Turning on the headlights
By operating
the switch, the lighting system of the Subaru Solterra activates in differ ...