System Venting (Allroad)

System venting (Allroad)
It is possible to perform a ventilation of the air spring system without having to loosen mechanical connections.
System filling via On Board Diagnostic (OBD) must only be performed with the vehicle standing!

WARNING: By venting the air springs, the self-supporting vehicle lowers itself.

Note:
^ The air spring system (pressure reservoir, air springs, pressurized air lines) can be vented up to the residual pressure of < 3.5 bar via VAG tester.
^ Venting the pressure reservoir is possible without entering a login code (display group number 20 - 21).
^ Venting the air springs is performed separately for front / rear, where the correction login-code must be entered right a way (display group 22 -25).
^ Venting is only possible after manually switching off the regulation. Switching off and on of the regulation is performed with the VAG tester (Fct. > 10, channel 10) or via manually pressing button for up and down (press button twice > 5 seconds).
^ Time frame for venting is limited to 65 seconds. However, it is possible to perform the function several times in sequence to accumulate a longer venting time.
^ It is possible to perform a filling procedure in stages using the up and down arrow buttons of the VAG tester. (buttons 113 of VAG1551 tester have the additional assignment I -button / t - button )

On Board Diagnostic (OBD), technical data
Equipment
^ Data is transmitted between the control module and the VAS 5051 tester or VAG 1551 Scan Tool (ST) via operating mode "Rapid Data Transfer".
^ DTC memory is designed for permanent memory and is therefore not dependent on voltage supply.

VAS 5051 tester or VAG 1551 scan tool, connecting and selecting functions
Test requirements:
^ Battery voltage at least 11 V
^ Ground (GND) connections at engine and transmission OK
^ Engine off
^ Automatic transmission in position T" or "N"

Work sequence

^ Connect VAS 5051 tester with VAS 5051/1 diagnostic wire with the ignition switched off. Alternately, VAG1551 Scan Tool (ST) can also be attached using VAG1551/3A adapter.

Note: The following description only explains implementation of On Board Diagnostic using VAG 1551 Scan tool. When using the VAS 5051 tester, observe instructions in the tester's user manual

Indicated on display:
1) Operating modes 1 and 2 are displayed alternately

Note: If nothing appears in display:

=> Operating instructions for Scan Too/ (ST)
^ Switch ignition on.
^ Switch off level control system manually (pressing button twice >5 seconds on manual control head)
^ Press -Print- button to turn on Scan Tool (ST) printer. Indicator lamp in button must light up.
^ Press button 1 to select "Rapid data transfer' operating mode 1.

When indicated on display:

Note: The address word 00 initiates Me automatic test sequence, i.e. it results in a DTC check on all OBD capable systems in the vehicle via rapid data transfer.

^ Press "34" for address word "Level control system".

Indicated on display:
^ Press -Q- button to confirm input

Indicated on display:

^ Indicated on display after approximately 5 seconds:
^ Press -> button.

Indicated on display:

Note: Pressing the -HELP- button will print out an overview of all of the possible functions.
^ Press button -l- twice for the "Login procedure" and press -Q- button to confirm input

Indicated on display:
^ Press -Q- button to confirm input

Indicated on display:
^ Press button 0, 8, 3, 6 and 7.

Indicated on display:
^ Press -Q- button to confirm input

When indicated on display:
^ Press buttons 0 and 4

When indicated on display:
^ Press -Q- button to confirm input

When indicated on display:
^ Enter display group number.
^ Press buttons 0, 2 and 0
^ Press -Q- button to confirm input

When indicated on display:
^ Press t - button to continue

When indicated on display:

Note:
^ Press \/ button to return to GE 20

When indicated on display:
^ Press t -button to continue

When indicated on display:

Note:
^ Press button to return to GE 22

For indication on display after expiration of 65 seconds or pressure lower than 3.5 bar in pressure reservoir:

Note: However, Me venting procedure can be aborted prematurely by exiting the display group number.

^ Press /\ -button to continue

When indicated on display:
^ Press /\ button to continue

When indicated on display:

Note:
^ Press \/ button to return to GE 24

For indication on display after expiration of 65 seconds or pressure lower than 3.5 bar in pressure reservoir:

Note:
However, the venting procedure can be aborted prematurely by exiting the display group number.
If the residual retaining pressure of 3.5 bar is not reached after expiration of 65 seconds, the message "...venting function aborted" appears instead of the message "venting function done".

^ Disconnect diagnostic cable from Data Link Connector (DLC)
Other filling procedures can follow according to the above mentioned scheme. The order (venting air springs - front axle, air springs -rear axle, pressure reservoir) can be specified as desired.
Note that upon exiting the filling mode, the regulation still remains manually switched off, as long as it is not switched on or a speed of v > 15 km/h is recognized.