Heater And A/C Unit, Removing And Installing: Removing

• When removing the bolts, make note of the lengths and allocation.
• All cable ties and other wiring harness fasteners released or cut open when removing the heater and A/C units are to be re-attached in same position on installation.
• Seal open line connections at the connection point with clean plugs, for example from the Engine Bung Set :VAS6122  .

Vehicles with High-Voltage System

-- Switch off (deactivate) the "parking air conditioner". Refer to Owner's Manual.

-- Initiate the basic setting of the A/C system using the Thermal Management Control Module -J1024- and open the electric valves using the routine "Refrigerant Circuit, Extract, Evacuate and Fill" in the Vehicle Diagnostic Tester.

Continuation for All Vehicles

-- Switch the ignition off.

-- Discharge the refrigerant circuit. Refer to Refrigerant Circuit or Working with A/C Service Station (1 Of 2) / Working with A/C Service Station (2 Of 2) .

-- Remove the plenum chamber bulkhead. Refer to PLENUM CHAMBER BULKHEAD, REMOVING AND INSTALLING .

-- Bleed the coolant for the engine coolant circuit. Refer to [For engine(s) DKMB, DLZA] COOLANT, DRAINING AND FILLING .

-- Label the layout of the coolant hoses on the connections to the heat exchanger -B- (supply) and -A- (return to engine).

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-- Clamp off the coolant hoses -A and B- using the Hose Clamps - Up To 25mm :3094  .

-- Cover the area under the connections for coolant hoses -A and B- in the plenum chamber, for example with absorbent paper.

-- Place a small container under the connections for coolant hoses -A- (to the heater core).

-- Remove the coolant hoses -A and B- from the connections to the heater and A/C unit heater core.

-- Insert one section each of hose -A and B- on to both connections to heater core.

Fig 1: Hoses And Compressed-Air Gun

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-- Place the container -B- under the other end of the hose -C-.

-- Using a compressed air gun -D-, carefully blow coolant out of the heater core against the normal flow direction of the coolant) via the hose -A- into a container -B-.

-- Disconnect the refrigerant lines from the front expansion valve and move to the side (do not remove). Refer to EXPANSION VALVE, REMOVING AND INSTALLING .

-- Loosen the grommet -A- with the support ring -B- from the plenum chamber rear panel toward the passenger compartment (it is removed and installed with the heater and A/C unit).

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-- Remove the instrument panel crossmember. Refer to INSTRUMENT PANEL CROSSMEMBER, REMOVING AND INSTALLING .

-- Remove the rear air duct. Refer to REAR AIR DUCT, REMOVING AND INSTALLING .

Vehicles with Auxiliary Heater Heating Element -Z35-

-- Interrupt the power supply to the Auxiliary Heater Heating Element -Z35- by pulling on the related fuse. Refer to Wiring Diagram.

Continuation for All Vehicles

-- Disconnect the connector -B- for the Auxiliary Heater Heating Element - Z35- -A-.

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Continuation for All Vehicles

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-- Remove the condensation water drain hose -A- from the left and right connection -B- on the heater and A/C unit.

-- Cover the floor covering in the area of the center tunnel with a sturdy mat.

-- Loosen the grommet -E- for the coolant pipes to the heater core and loosen the grommet -D- for the expansion valve/connection from the openings in the plenum chamber rear panel.

-- Loosen the heater and A/C unit -C- carefully from the vehicle (so that no components are damaged by any connections not yet loosened) and remove toward the front passenger footwell.