Air Flow Door Motor (V71), Function

Air Flow Door Motor (V71), Function

with Back Pressure Door Motor Position Sensor (G113)

• You can check the adjustment motor's function via the "output diagnostic test mode" Vehicle diagnosis, testing and information system (VAS5051B) in the "Guided Fault Finding" or check it without a tester as follows: if not using a tester, connect both contacts 5 and 6 on the adjustment motor's connector to a 12 volt DC source. The adjustment motor will move in one direction up until the stop, and will reverse direction if the plus and minus contacts are switched. Use an adapter cable. Refer to => [ Adapter Cable for Activating Control Motors ] Adapter Cable for Activating Control Motors.

• Perform a basic setting on the A/C after installing a new motor. Refer to Vehicle diagnosis, testing and information system (VAS5051B) in the "Guided Fault Finding".

• Use "output diagnostic test mode" and "basic setting" to test the activation of A/C (heater) electrical components, if necessary (for example, allocation test) using Vehicle diagnosis, testing and information system (VAS5051B) in the "Guided Fault Finding".

• The position of the back pressure door - A - is visible via the air intake opening in the plenum chamber when the recirculation door - E - is open (if necessary, remove plenum chamber cover and cover over fresh air intake. Refer to=> [ Fresh Air Intake Cover ] Fresh Air Intake Cover).






• For back pressure regulation (currently only intended on vehicles with A/C system), the fresh air intake channel is partially closed via the back pressure door - A - at high speeds (from approximately 80 km/h) by the Climatronic control module (J255) (position of recirculation door - E - is specified by the Climatronic control module).

• To reduce the change in noise from the fresh air blower (V2) due to different air intake when switching from fresh air to recirculation or vice versa, the airflow door motor (V71) and recirculation door motor (V113) are activated as follows:

- When switching from fresh air to recirculation mode, the recirculation door - E - is first opened, then the fresh air intake channel is closed via the back pressure/fresh air door - A -.

- When switching from recirculation to fresh air mode, the fresh air intake channel is first closed by the back pressure/fresh air door - A -, then the recirculation door - E - is closed.

- In partial recirculation mode (currently only intended on vehicles with A/C system), the recirculation door - E - is opened and the back pressure/fresh air door - A - is brought into a center position by the Climatronic control module (fresh air and recirculation air channel are simultaneously opened slightly). This achieves improved cool-off in certain temperature ranges and simultaneously draws in a certain portion of fresh air as well.

• Airflow door motor (V71) , removing and installing, refer to => [ Air Flow Door Motor (V71) ] Air Flow Door Motor (V71).