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 InspectionElectric Variable Valve Timing Motor/Driver Inspection
WARNING:
A hot engine can cause severe burns. Turn off the engine and wait until it
is cool before servicing.
CAUTION:
Do not disassemble the electric variable valve timing motor/driver because
it is a precision unit.
Do not apply excessive force when rotating the ...
On/Off Solenoid Removal/Installation [Fw6 A EL, Fw6 Ax EL]
WARNING:
A hot transaxle and ATF can cause severe burns. Turn off the engine and wait
until they are cool.
Always wear protective eye wear when using the air compressor. If the air
compressor is used, any particles of dirt or soiling could spatter and get into
the eyes.
...
Headlight Auto Leveling System
Outline
Automatically adjusts the headlight optical axis in response to changes in
load and passenger conditions to prevent blinding of oncoming vehicles from
headlight glare and to assure a range of visibility.
The AFS control module performs headlight auto leveling system fail ...