Battery assistance mode using battery charger VAS 5095A, VAS 5900 or VAS 5903

The battery assistance mode is used, e.g. for battery replacement in the workshop when troubleshooting.
In the following, the battery assistance mode is described acting for battery charger VAS 5900.

Special tools, testers and auxiliary items required

Fig 1: Battery Charging Unit VAS 5095 A

Courtesy of VOLKSWAGEN UNITED STATES, INC.

Battery charger VAS 5095A or

Fig 2: Battery Charging Unit VAS 5900

Courtesy of VOLKSWAGEN UNITED STATES, INC.

Battery charger VAS 5900 or

Fig 3: Battery Charging Unit VAS 5903

Courtesy of VOLKSWAGEN UNITED STATES, INC.

Battery charging unit VAS 5903

Work procedure

Switch ignition off and remove ignition key.
Switch off all electrical components.
Connect power plug of battery charger VAS 5900.

The last selected operating mode appears on the display.

Press Start/Stop button for approx. 5 seconds.

Menu item "charging of severely discharged batteries / assistance mode" is activated.

Press button ↑ or ↓ in order to adjust the vehicle electrical system.

NOTE:

If no button is pressed within 5 seconds, the battery charger VAS 5900 switches back to the main menu.
Select the battery voltage by pressing the Start/Stop button.

Fig 4: Identifying Luggage Compartment Cargo Floor And Spare Wheel Cover

Courtesy of VOLKSWAGEN UNITED STATES, INC.

Vehicles with ground (GND) pin in luggage compartment

Sedan:

Lift and secure luggage compartment floor mat.

Avant:

Remove luggage compartment storage area floor - 1 - and cover for spare wheel - 2 -.

Fig 5: Identifying Cover, Ground Pin, Battery Charger Pliers, And Ground Wire Pliers

Courtesy of VOLKSWAGEN UNITED STATES, INC.

Remove cover - 2 - above battery positive terminal.
Clamp battery charger pliers - 1 - of positive wire to batterys B+ terminal "+".
Clamp ground (GND) wire pliers - 3 - of battery charger to ground pin - arrow - of Energy Management Control Module J644.

Vehicles with ground (GND) pin in luggage compartment

Open cover - arrow - above battery positive terminal.
Clamp positive wire clamp of battery charger to B+ terminal tap "+", and clamp ground (GND) wire pliers of battery charger to negative terminal tap "".

All:

The charging clips are checked for connection to correct poles.

CAUTION: The Start/Stop button must not be operated when the charging clips are not connected correctly, otherwise battery charger VAS 5900 or vehicle electronics are damaged.

Confirm charging clips are connected to correct poles via Start/Stop.

The battery charger VAS 5900 starts the assistance mode.

The battery can now be removed.

Press Start/Stop button to end assistance mode only after replacing the battery.
Disconnect power plug.