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 InspectionEvaporative Emission (Evap) Control System
Purpose, Outline
Prevents release of evaporative gas into the atmosphere.
The intake manifold vacuum introduces evaporative gas to the intake manifold
via the charcoal canister and the purge solenoid valve.
System Diagram
U.S.A. and CANADA
Except U.S.A. and CANADA
...
Bsm Indicator Light Flashes While Not Under Bsm Indicator Light Flashing Conditions
(No Combination Switch Operation (Turn Signal Switch)) [Blind Spot Monitoring (Bsm)]
Description
BSM indicator light flashes while not under BSM indicator light-flashing
conditions (no combination switch operation (turn signal switch)
The BSM indicator light flashes despite not satisfying the BSM indicator
light flashing ...
Presilencer
Purpose, Function
Reduces the exhaust noise.
Construction
The presilencer is installed to the rear of the TWC.
2WD
AWD
The presilencer consists of the filters, stuffing and wool-stainless.
2WD
AWD
...