The following steps should always be carried out in the specified order before working in the engine compartment :

Park the vehicle on a level and stable surface.

Depress and hold the brake pedal until the engine has stopped.

Apply the handbrake firmly Braking, stopping and parking Brakes Parking .

Select the neutral position or move the selector lever to P Changing gear Changing gear Automatic gearbox see Automatic gearbox_0 Automatic gearbox see Changing gear_0 Automatic gearbox Manual gearbox see Changing gear_0 Manual gearbox .

Stop the engine and remove the key from the ignition Starting and stopping the engine Engine and ignition Ignition see Engine and ignition_6 .

Allow the engine to cool sufficiently.

Children and other people should be kept well away from the engine compartment.

Ensure that the vehicle cannot roll away unexpectedly.

WARNING
Preparing the vehicle for working in the engine compartment
Opening and closing the bonnetSupport Mode with Battery Charger -VAS5095A
General Information
The support mode provides the vehicle electrical system with
voltage when the battery is removed or disconnected.
For more information. Refer to Battery Charger -VAS5095A-
Operating Instructions.
...
Charging Systems not Requiring a Permit
At this time, A/C service units for extracting, cleaning and
filling refrigerant for motor vehicle A/C systems are available
from various manufacturers.
Charging systems not requiring a permit are ones used for
transferring compressed ga ...
Special Tools
Special tools and workshop equipment
required
Torque Wrench 1331 5-50Nm -VAG1331-
Crimping Pliers, Complete -VAS1978/1A-
...