Heater And A/C Unit, Removing And Installing: Removing
-- Move the driver and passenger seats as far back as possible.
-- Turn off the ignition.
-- Discharge the refrigerant circuit. Refer to USING SERVICE STATION (Refrigerant R134a, Servicing; Refrigerant Circuit, Using Service Station).
Depending on the allocation of the service connection to the refrigerant line and vehicle version, it may be necessary to remove the left additional reinforcement on the tower brace so that the service coupling of the A/C service station can be connected (for example, on the Audi Q5). Refer to OVERVIEW - SUSPENSION STRUT WITH MOUNTING BRACKET, SHOCK ABSORBER FORK, UPPER CONTROL ARM AND TOWER BRACE and USING SERVICE STATION (Refrigerant R134a, Servicing; Refrigerant Circuit, Using A/C Service Station).
On vehicles with a high voltage system (hybrid vehicles)
Observe all of the additional warnings for all work performed on vehicles with the high voltage system. Refer to HIGH VOLTAGE VEHICLES SAFETY PRECAUTIONS and HIGH VOLTAGE SYSTEM GENERAL WARNINGS .
If it is necessary for the following procedure to perform work near high voltage components, "perform a visual inspection of the high voltage components and cables for damages" (refer to PERFORMING A VISUAL INSPECTION OF DAMAGE TO HIGH VOLTAGE COMPONENTS AND CABLES ) and "always follow the warnings when working on the high voltage system". Refer to HIGH VOLTAGE SYSTEM GENERAL WARNINGS .
Risk of unintended engine start
The ignition must be turned off and the ignition key must remain outside of the vehicle when working on vehicles with a high voltage system.
Handling high voltage cables:
- Do not stand on or place tools on high voltage cables and their components as it may damage the cable insulation.
- Never bend or kink high voltage cables forcefully as it may damage the cable insulation.
- The round high voltage connectors are color coded with an external color ring and are mechanically coded using the guide- or code tabs. Always make certain that the coding matches when connecting the round connector in order to avoid any mechanical damage the high voltage connector.
There is a risk of electrocution from damaged high voltage components.
Observe the following when working around high voltage components and high voltage wires:
- Never work around high voltage components and cables with cutting, deformed, or sharp edged tools, or heat sources such as welding or soldering tools, heated air, and thermal glue.
- Inspect the high voltage components visually before beginning.
- Perform a visual inspection of the Electric Drive Power and Control Electronics -JX1-, the Electro-Drive Drive Motor -V141-, the Electrical A/C Compressor -V470- and the high voltage lines when working in the engine compartment.
- Perform a visual inspection of the high voltage lines and covers when working on the underbody.
- Perform a visual inspection of the high voltage lines and the Electrobox with the High Voltage System Maintenance Connector -TW- when working in the luggage compartment.
- Perform a visual inspection on all of the potential equalization cables.
Observe the following items when performing the visual inspection:
- The components do not display any signs of external damage.
- The high voltage cable insulation and the potential equalization cables are not damaged.
- The high voltage cables do not display any abnormal deformations.
- Every high voltage component is marked with a red warning label.
De-energize the high voltage system to perform the necessary work on the high voltage system for the following procedure. Refer to HIGH VOLTAGE SYSTEM, DE-ENERGIZING and "read and follow the high voltage electrical system general warnings" in HIGH VOLTAGE SYSTEM GENERAL WARNINGS .
-- De-energize the high voltage system. Refer to HIGH VOLTAGE SYSTEM, DE-ENERGIZING .
High Voltage System,
Risk of electrocution
Death or serious bodily injury by electric shock.
- The high voltage system may only be activated by qualified personnel (Audi high voltage mechanic).
- Make sure that the high voltage system is completely disabled. Make sure the vehicle is de-energized using "Guided Fault Finding " on the Vehicle Diagnostic Tester.
- The qualified personal (Audi high voltage technician) determines the voltage and secures the system from restarting using the Service Disconnect Lock T401262. Keep the ignition key and the High Voltage System Maintenance Connector -TW- safely with the qualified personal to secure the system from restarting.
- The Audi high voltage technician should put a sign on the vehicle to identify it as a high voltage vehicle.
Disable the high voltage system:
Connect the vehicle diagnostic tester.
Select the Guided Fault Finding mode.
Using the GO TO button, select the following menu commands
Function/Component Selection
Body
Electrical Equipment
OBD-capable systems
8C - Battery Regulation Control Module -J840
8C - Battery Regulation Control Module, functions
51 - De-energize the high voltage
-- Remove the rubber seal -A- and plenum chamber cover -B- (different versions). Refer to PLENUM CHAMBER COVER, REMOVING AND INSTALLING .
-- Visually inspect the high voltage components -D- (here the Electric Drive Power and Control Electronics -JX1-) and the high voltage cables -E- after removing the plenum chamber cover -B-. Refer to PERFORMING A VISUAL INSPECTION OF DAMAGE TO HIGH VOLTAGE COMPONENTS AND CABLES and HIGH VOLTAGE SYSTEM GENERAL WARNINGS .
-- Disconnect the ground connection from the Battery -A-. Refer to BATTERY, DISCONNECTING AND CONNECTING or Battery -A- AND Auxiliary Battery -A1-, DISCONNECTING AND CONNECTING, VEHICLES WITH HIGH VOLTAGE SYSTEM .
-- Loosen the power distribution panel -1- and move it toward the windshield with the wires. Refer to OVERVIEW - RELAY PANELS, FUSE PANELS AND E-BOXES .
-- Remove the high voltage cables to the Electric Drive Power and Control Electronics -JX1-. Refer to OVERVIEW - HIGH VOLTAGE CABLES .
-- Cover the Electric Drive Power and Control Electronics -JX1- and related wires to prevent them getting damaged and to protect them from dirt. Refer to HIGH VOLTAGE SYSTEM GENERAL WARNINGS .
For example, use clean 20 mm bungs -B- from the Engine Bung Set VAS6122 to seal off the connections on the Electric Drive Power and Control Electronics -JX1- -A-.
- Be careful not to damage any high voltage components -D- or the high voltage cables -E-. Refer to HIGH VOLTAGE SYSTEM GENERAL WARNINGS .
To remove and install the expansion valve, it may be necessary to remove the cowl panel trim -C-. Refer to PLENUM CHAMBER COVER, REMOVING AND INSTALLING .
For vehicles without a high voltage system
-- Disconnect the ground connection from the Battery -A-. Refer to BATTERY, DISCONNECTING AND CONNECTING or Battery -A- AND Auxiliary Battery -A1-, DISCONNECTING AND CONNECTING, VEHICLES WITH HIGH VOLTAGE SYSTEM .
-- Remove the plenum chamber cover and/or the cowl panel trim (different versions). Refer to PLENUM CHAMBER COVER, REMOVING AND INSTALLING .
-- Disconnect the ground connection from the Battery -A-. Refer to BATTERY, DISCONNECTING AND CONNECTING or Battery -A- AND Auxiliary Battery -A1-, DISCONNECTING AND CONNECTING, VEHICLES WITH HIGH VOLTAGE SYSTEM .
The Battery -A- ground connection is disconnected so that it will not short circuit when the jumper cable post -C- is removed and when disconnecting the positive cable to both relays for the Auxiliary Heater Heating Element -Z35- -J-.
-- Remove the jumper cable post cover -C-.
All vehicles
-- For vehicles with an Auxiliary Heater Heating Element -Z35-, loosen the positive cable to both relays for the Auxiliary Heater Heating Element -Z35- -J- from the jumper cable post -C-. Refer to OVERVIEW - RELAY PANELS, FUSE PANELS AND E-BOXES .
-- If equipped and necessary, remove the tower brace -B- (for example, on the Audi A5 Coupe; not necessary, for example, on the Audi Q5).
-- For vehicles with a 6-Cylinder TDI engine, remove the plenum chamber front wall -A-. Refer to OVERVIEW - BULKHEAD .
On vehicles with a gasoline engine or a 4-Cylinder TDI engine, the plenum chamber front wall must not be loosen or removed from the vehicle (there is enough space).
On vehicles with a gasoline engine or a 4 cylinder TDI engine, both coolant hoses to the heater core are routed through the plenum chamber front wall -A-. On these vehicles, loosen the grommet on both coolant hoses and move the plenum chamber front wall to the side (when doing this, the refrigerant circuit must not be opened).
When loosening the plenum chamber front wall, be careful not to damage the brake booster vacuum line.
-- Remove the expansion valve. Refer to EXPANSION VALVE, REMOVING AND INSTALLING .
The air conditioner can be removed and installed with the expansion valve still installed. Removing and installing with the expansion valve removed is described here due to the increased space.
Seal open pipe connections.
To seal off all open connections on expansion valve, sealing caps from a replacement expansion valve can be used (preventing dirt and moisture from entering the system).
-- Remove the expansion valve mounting plate -A- from the refrigerant lines -B- and -C- (so that it does not get lost while removing).
-- Coat the inner side of the grommet -D- with grease and remove the supporting ring -E-.
-- Loosen the grommet -D- from the plenum chamber rear wall toward the passenger compartment (it is removed and installed with the A/C unit).
-- Open the cap on the coolant expansion tank and release the pressure in the coolant system. Refer to DRAINING for CALB, DRAINING for CPNB, DRAINING for CTUC and CTUD, DRAINING for CAEB, CPMB, CPMA, or DRAINING for CHJA .
-- Mark the arrangement of coolant hoses -A- (supply to cylinder head) and -B- (return to coolant pump).
The heater core is designed for a specific coolant flow direction. Therefore, coolant hoses must be connected on the correct sides.
Bleed the coolant circuit. Refer to FILLING for CALB, FILLING for CPNB, FILLING for CTUC and CTUD, FILLING for CAEB, CPMB, CPMA, or FILLING for CHJA .
Note: bleeding may be a part of "Coolant Mixture" in some draining and filling procedures.
-- Clamp the coolant hoses -A- and -B- with hose clamps.
-- Cover the area beneath connections for coolant hoses -A- and -B-, for example, with absorbent paper.
-- Remove the coolant hoses -A- and -B- from the connections to the A/C heater core. Refer to CONNECTION DIAGRAM - COOLANT HOSES for CALB, CONNECTION DIAGRAM - COOLANT HOSES for CPNB, CONNECTION DIAGRAM - COOLANT HOSES for CTUC and CTUD, COOLANT HOSE, CONNECTION DIAGRAM, NON-HYBRID VEHICLES WITH ALL ENGINE CODES EXCEPT CDZA for CAEB, CPMB, CPMA, or CONNECTION DIAGRAM, COOLANT HOSE, HYBRID VEHICLES for CHJA, .
-- Insert one section each of hose -A- and -B- on to both connections to heater core.
-- Place a container -B- under the other end of the hose -C-.
-- Using a compressed air gun -D-, carefully blow coolant out of heater core (into container -B-) via hose -A-.
-- Loosen the grommet -H- from the plenum chamber rear wall and remove it from the heat exchanger coolant pipes.
-- Remove the glove compartment. Refer to GLOVE COMPARTMENT, REMOVING AND INSTALLING .
-- Remove the center console (refer to CENTER CONSOLE, REMOVING AND INSTALLING ) and the instrument panel (refer to INSTRUMENT PANEL, REMOVING AND INSTALLING ).
To prevent the instrument panel shell from damage, instrument panel should be placed on a clean work bench which is covered with clean cardboard.
-- Remove the air intake manifold. Refer to HEATER AND A/C UNIT AIR INTAKE HOUSING, REMOVING AND INSTALLING .
-- Remove the air guides to the left and right instrument panel vents.
The air guide channel leading the left instrument panel vent -A- is secured by an expanding clip or a screw -B- onto the instrument panel crossmember -C- ; the expanding clip or the screw can only be removed when the outer instrument panel shell is removed.
-- Remove the air guides to the instrument panel center vents -C- and to the defrost vent -D-.
-- Remove the bolts -A- and -B-.
-- Remove the steering column. Refer to STEERING COLUMN, REMOVING AND INSTALLING .
-- Remove the connector from the Brake Lamp Switch -F-. Refer to BRAKE LAMP SWITCH, REMOVING AND INSTALLING .
-- Loosen the instrument panel crossmember (the central tube) -E- from the vehicle and the A/C unit. Refer to INSTRUMENT PANEL CENTRAL TUBE, REMOVING AND INSTALLING (See Fig 12) .
Except for the left fuse box, do not loosen any other left relay- or control module brackets from the instrument panel cross member.
-- Remove the air guide to the rear center console vent -C- (only on vehicles equipped with the "Convenience" A/C system).
-- Loosen the air guide to the rear footwell vents -A- and -B- from the intermediate piece -D- and remove the intermediate piece -D-.
-- On vehicles equipped with an Auxiliary Heater Heating Element -Z35-, loosen the ground connection -A- and disconnect the connector -B-. Refer to Auxiliary Heater Heating Element -Z35-, REMOVING AND INSTALLING .
-- Remove both condensation water drain hoses from the A/C unit. Refer to CONDENSATION WATER DRAIN, REMOVING AND INSTALLING .
-- Loosen the "driver side" fuse panel on the left side of instrument panel crossmember (the central tube) -A- from the instrument panel crossmember. Refer to LEFT INSTRUMENT PANEL FUSE HOLDER, REMOVING AND INSTALLING .
Since the instrument panel cross member is loosen only from the vehicle (not completely removed), the remaining relay-/fuse carriers and connector stations must not be removed from the instrument panel cross member
-- Loosen all electric connections between the instrument panel cross member and the vehicle on the passenger side -B-.
-- Cover the carpet in the area of the center tunnel with a mat -C- (and both seats if not already done).
The instrument panel cross member must not be completely removed in order to remove the A/C unit; it is enough to disconnect the A/C unit from the vehicle and then to swivel it to the rear and place it on the center tunnel.
-- Carefully remove the instrument panel cross member from the vehicle and carefully swivel it (and when doing this not to damage any components) to the passenger side -B- far enough to the rear -arrow- so that the A/C unit can be removed to the right -arrow-.
-- Remove the vehicle wiring harness in the area of the instrument panel cross member from the A/C unit.
-- Carefully remove the A/C unit from the vehicle (with doing this, do not damage any connections and components still not removed).
-- On vehicles equipped with an Auxiliary Heater Heating Element -Z35-, mark the location of the mounting points -B- (with cable ties on the A/C unit) on the positive cable to both relays for the Auxiliary Heater Heating Element -Z35- -A- (for example, with a suitable pin on the cable).
-- Disconnect the cable -A- from the A/C unit.
-- Remove the remaining vehicle wiring harness mounts (for example with cable ties) on the A/C unit.
-- Remove the A/C unit -A- in the direction of the front passenger side.
The "A/C system" wiring harness is removed together with the A/C unit.