Rear Air Distributor Housing

Rear Air Distributor Housing

• In this vehicle, all control motors are currently identical. During the basic setting, the control motors are assigned and adapted corresponding to the switching sequence of the wiring. If this sequence does not conform with the specification, the control motors will adapt incorrectly and the door control will be wrong, refer to => [ A/C Control Motor Block Diagram ] A/C Control Motor Block Diagram.

• Perform the basic setting for the A/C system after installation of the rear air distributor housing using the Vehicle Diagnostic Tester in the "Guided Fault Finding" function.

• Using the output diagnostic test mode and basic setting functions, the activation of A/C system electrical components can be tested if necessary (for example allocation test) using the Vehicle Diagnostic Tester in the "Guided Fault Finding" function.

• After installing a new control motor, check the activation via the Climatronic control module (J255) , and the function of the control motor using the Vehicle Diagnostic Tester in the "Guided Fault Finding" function.

• For rear air distributor housing - C - to be removed, the entire center console including the base support of center console - A - and insulation mat - B - installed between the base support and rear air distributor housing - C - must be removed.






Removing

- Remove the driver and front passenger seat.

- Switch off the ignition.

- Remove the base support of center console - A - and insulation mat - B -.

• A/C system malfunctions in the case of interchanged control motors and/or connectors => [ A/C Control Motor Block Diagram ] A/C Control Motor Block Diagram.

• The control motors and connectors are identical. If they are installed or connected incorrectly, the corresponding doors cannot be properly adapted and/or activated.

• Clearly label control motors and connectors prior to removal to prevent incorrect installation.

• Rear air distributor housing - A - can also be removed with air duct - D - installed (from the front A/C unit to the rear air distributor housing). However, due to the easier execution, removal is described here with air duct - D - removed.






• Depending on the version, rear air distributor housing - A - can additionally be secured with a bolting point to the center tunnel (if necessary, remove hexagon nut - C -).

- Disconnect harness connector - B -.

- Remove connectors - C - from the rear fresh air blower control module (J391).






- Remove bolts - A -.






- Push air duct - C - forward (to the front A/C unit). Then lift air duct - C - at the back and remove in the - direction of the arrow -.

- Detach rear air distributor housing - D - from holding points - A - and air ducts - E - and remove.






Installing

Installation is carried out in the reverse order while observing the following.

- Check grommets - B -, - C -, and - F - for damage and proper seating.

• Grommets - B -, - C -, and - F - are only present in vehicles with an air distributor housing.

- Check holding points - A - for correct installation in the center tunnel and for damage.

- Check the ball heads on air distributor housing - D -, which are inserted in holding points - A -, for damage.

- Check the outlets at rear air distributor housing - D -, which are inserted in air ducts - E -, and air ducts - E -, for damage and contamination.

• Damaged or improperly joined components can result in noises during operation of the A/C system.

- Insert rear air distributor housing - D - in holding points - A - and air ducts - E -.

- Install the removed parts in the opposite order.

- Perform the basic setting and the output diagnostic test mode of the A/C system using the Vehicle Diagnostic Tester in the "Guided Fault Finding" function.

• In this vehicle, the control motors are equipped with electronics. During the basic setting, a new control motor learns its position on the A/C unit and can then be activated by the Climatronic control module (J255) (currently all control motors are identical). Check using the Vehicle Diagnostic Tester in the "Guided Fault Finding" function.

• During the basic setting, the control motors are assigned and adapted corresponding to the switching sequence of the wiring. If this sequence does not conform with the specification, the control motors will adapt incorrectly and the door control will be wrong, refer to => [ A/C Control Motor Block Diagram ] A/C Control Motor Block Diagram.

- Check the event memory of the Climatronic control module and erase any displayed malfunctions using the Vehicle Diagnostic Tester in the "Guided Fault Finding" function.