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 InspectionHeated Oxygen Sensor (HO2 S) Removal/Installation
WARNING:
A hot engine and exhaust system can cause severe burns. Turn off the engine
and wait until they are cool before removing the exhaust system.
CAUTION:
Do not allow flammable objects such as the taping for bundling wiring harness
to come into contact with the exhau ...
Negative Battery Cable Disconnection/Connection [Skyactiv G 2.0]
WARNING:
Before removing the SRS air bag system-related parts, always disconnect the
negative battery cable and wait for 1 min. or more to allow the back-up power
supply to deplete its stored power..
Required procedure after negative battery cable disconnection/connection
...
Positive Crankcase Ventilation (PCV) Valve Removal/Installation
1. Disconnect the negative battery cable..
2. Remove the intake manifold..
3. Remove in the order indicated in the table.
4. Install in the reverse order of removal.
1
PCV hose
2
Oil separator
3
Retainer
( ...