1. Disconnect the brake fluid level sensor connector from the master cylinder.
2. Inspect for continuity according to fluid level between the brake fluid level sensor terminals.

If not as indicated in the table, replace the reserve tank.

Brake Switch InspectionUtility vehicle precautions
The Subaru Solterra belongs to the utility vehicle category, engineered
with increased ground clearance and a comparatively narrower track width relative
to its center of gravity height. This design allows the Subaru Solterra to perform
effectively across a wide range of off-road environments ...
Fuel Injector Inspection [Mzr 2.0, Mzr 2.5]
Resistance Inspection
1. Remove the battery cover..
2. Disconnect the negative battery cable..
3. Disconnect the fuel injector connector.
4. Inspect the resistance between fuel injector terminals A and B.
Fuel injector resistance
11.4—12.6 ohms [20 °C {68 °F}]
If ...
Non Return Valve Inspection [Skyactiv G 2.0]
WARNING:
Fuel is very flammable liquid. If fuel spills or leaks from the pressurized
fuel system, it will cause serious injury or death and facility breakage. Fuel
can also irritate skin and eyes. To prevent this, always complete the “Fuel
Line Safety Procedure”, while referring ...