1. Remove the vacuum hose..
2. Verify that air can be blown from the power brake unit side of the vacuum hose towards the vacuum pump side, and that air cannot be blown in the opposite direction.

If there is any malfunction of the inner check valve, replace it together with the vacuum hose as a single unit.
Vacuum Hose Removal/Installation
Vacuum Pump InspectionFilament Inspection
1. Switch the ignition ON (engine off).
2. Turn the rear window defroster switch on.
CAUTION:
Directly touching the rear window defroster filament with the lead of the
tester could damage it. Wrap aluminum foil around the end of the lead and inspect
the filament by touching it ...
Fuel Tank Removal/Installation
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 ...
Afs (Adaptive Front Lighting System) Control Module
Purpose
The AFS control module calculates the target optical axis based on the vehicle
height signal and outputs the target optical axis signal to the headlight leveling
actuator.
Function
The AFS control module performs control of the AFS and headlight auto leveling.
...