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.

Side Turn Light Removal/InstallationWheel Hub Component Removal/Installation
CAUTION:
Performing the following procedures without first removing the ABS wheel-speed
sensor may possibly cause an open circuit in the wiring harness if it is pulled
by mistake. Before performing the following procedures, disconnect the ABS wheel-speed
sensor connector (axle side) ...
Air conditioning filter
To ensure optimal performance of the climate control system in your
Subaru Solterra, the air conditioning filter must be inspected and replaced at regular
intervals.
A clean air conditioning filter in the Subaru Solterra not only improves
airflow efficiency but also enhances cabin air quality ...
Camshaft Position (CMP) Sensor Removal/Installation [Mzr 2.0, Mzr 2.5]
CAUTION:
When replacing the CMP sensor, make sure there is no foreign material on
it such as metal shavings. If it is installed with foreign material, the sensor
output signal will malfunction resulting from fluctuation in magnetic flux and
cause a deterioration in engine control.
...