Fresh Air Blower Control Module (J126)

Fresh Air Blower Control Module (J126)

• There are different versions for vehicles with and without the parking/auxiliary heater. Refer to the Electronic Parts Catalog.

• Starting in November 2007, the Comfort A/C system has an updated fresh air blower control module (an updated Climatronic control module (J255) for the Comfort system and an updated Fresh Air Blower (V2) ). For the correct allocation, refer to the Electronic Parts Catalog.

• Through November 2007, vehicles with an A/C system, regardless of the version, always have a fresh air blower control module - D - part number 7L0 907 521, a fresh air blower part number 7L0 820 021 each with different indexes and Climatronic control module part number 4L0 820 043 through index J. Refer to the Electronic Parts Catalog.






• From November 2007, vehicle with the Comfort A/C system, as a running change, have a fresh air blower control module - D - part number 3C0 907 521 beginning with index B, a fresh air blower part number 4LX 820 021 with different indexes and a Climatronic control module part number 4L0 820 043 starting with index K (there are no changes to the Basis A/C system). Refer to the Electronic Parts Catalog. Pay attention to the correct allocation whenever replacing one of these components.






• The fresh air blower control module, part number 3C0 907 521 starting with index B switches from contact 4 on terminal - C - to contact 1 on terminal - B - when the ignition is on and the fresh air blower Plus. Fresh Air Blower speed is regulated by fresh air blower control module via the Ground (GND) connection between terminal 2 of connector - B - and terminal 3 of connector - C -. Refer to and Vehicle Diagnosis, Testing and Information System VAS 5051 in the "Guided Fault Finding" function.

Heat sink may be hot.

Removing

- Switch off ignition.

- Remove glove compartment.

Continuation for version 1

- Disconnect connectors - B - and - C - from fresh air blower control module.






- Remove bolts - A -.

- Remove fresh air blower control module - D -.

Continuation for version 2

- Disconnect connectors - B - and - C - from fresh air blower control module.






- Remove bolts - A -.

- Remove fresh air blower control module - D -.

Installing

- Install the fresh air blower control module according to the version of the A/C system.

- Install the remaining removed components again in reverse order.

- Check the DTC memory for the Climatronic control module and erase any faults displayed if necessary using the Vehicle diagnosis, testing and information system VAS 5051 in the "Guided Fault Finding" function.

- If necessary, perform a basic setting and output diagnostic test mode on the A/C system using the Vehicle diagnosis, testing and information system VAS 5051 in the "Guided Fault Finding" function.