Heater And A/C Unit, Removing And Installing: Installing
Install in reverse order of removal. Note the following:
Before installing, check all gaskets and grommets on the A/C unit for damage and replace if necessary.
-- Install the A/C unit -A- and the components also removed with the A/C unit (wiring harness "A/C unit", grommet on the evaporator refrigerant lines, etc.) in the vehicle
-- Coat the grommet -D- with grease and install it in the plenum chamber rear wall.
-- Install the support ring -E- in the grommet -D-.
-- Install the instrument panel cross member (central tube). Refer to INSTRUMENT PANEL CENTRAL TUBE, REMOVING AND INSTALLING .
-- Install the expansion valve mounting plate -A- to the refrigerant lines -B- and -C-.
-- Install the grommet -H- in the plenum chamber rear wall.
-- Check the position of the coolant and refrigerant line in both grommets, and if necessary, align the A/C unit so that the lines are not tensioned in the grommets.
-- Install the screws -A-.
-- Slide the strap -F- all the way to the bracket -H-, then turn it downward (when doing this, the bracket -G- locks the A/C unit to the strap)
-- Install the bolts -B-.
-- Connect both condensation water drain hoses to the A/C unit. Refer to CONDENSATION WATER DRAIN, REMOVING AND INSTALLING .
When installing the intermediate piece, -D-, the air guides to the rear footwells -A- and -B- and the air guide to the vent in the rear center console -C- make sure that they fit correctly and are securely connected. If the connection points are not connected tightly, warm or cool air could leak out and influence how the A/C system works (this air will be drawn in by the Interior Temperature Sensor Fan -V42- and the measured value for the Instrument Panel Temperature Sensor -G56- will deviate from the actual temperature in the passenger compartment).
The intermediate piece -D- latches on the air outlet openings on the air conditioner. There are slits inside the intermediate piece -D-. If the door position is incorrect, especially on vehicles with the "Convenience" A/C system, whistling noise can come from these slits. The upper slits are covered with tape during production (adhesive strips from 02/2009 as a running change). Refer to REAR VENT AIR GUIDE SLOTS, SEALING .
-- Install the air intake housing. Refer to HEATER AND A/C UNIT AIR INTAKE HOUSING, REMOVING AND INSTALLING .
-- Install the expansion valve. Refer to EXPANSION VALVE, REMOVING AND INSTALLING .
-- Install the refrigerant line with inner heat exchanger. Refer to REFRIGERANT LINES WITH INNER HEAT EXCHANGER, REMOVING AND INSTALLING
-- Make sure the grommet -H- fits correctly in the back of the plenum chamber.
-- Pay attention to the marking and properly connect the coolant hoses to the heater core.
A -
Supply hose from cylinder head
B -
Return to the coolant pump
-- Connect the coolant hose -A- to the heater core coolant pipe (pay attention to the marking) and secure it with the clamp -D-.
-- Attach the coolant hose to the heater core -B- onto the coolant pipe -F- just far enough as to not cover the bleed hole -G-.
-- Remove the hose clamp from the coolant hose -A-.
-- Fill the coolant expansion tank with coolant. Refer to FILLING for CALB, FILLING for CPNB, FILLING for CTUC and CTUD, FILLING for CAEB, CPMB, CPMA, or FILLING for CHJA .
-- Carefully force the coolant out of the coolant overflow reservoir into the heater core using, for example, the hand pump from the Cooling System Tester VAG1274B.
-- As soon as the coolant comes out the ventilation hole -G-, install the coolant hose -B- on to the coolant pipe -F- at the marking.
-- Secure the coolant hose -B- with the clamp -E- on the marked location.
-- Remove the hose clamp from the coolant hose -B-.
-- Add more coolant to the coolant expansion tank, if necessary. Refer to FILLING for CALB, FILLING for CPNB, FILLING for CTUC and CTUD, FILLING for CAEB, CPMB, CPMA, or FILLING for CHJA .
This procedure completely bleeds the cooling system. If, for some other reason, there is still some air in the cooling system, bleed the coolant system after installing all of the removed components, if necessary. 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 Ratio" in some draining and filling procedures.
Check the connections at the heater core for leaks as follows:
-- Carefully increase the pressure in the coolant circuit by using, for example, the hand pump of the Cooling System Tester VAG1274B.
-- Check coolant circuit for leaks, pay particular attention to the connection between coolant hoses and heater core Engine Mechanical.
This illustration shows the coolant pipes on a replacement heater core. The coolant pipes are attached to the heater core by clamps. Refer to HEATER CORE, REMOVING AND INSTALLING .
When bleeding the coolant circuit, take special care to ensure complete bleeding of the heater core. If there are still air bubbles in the heater core, it may cause the customer to complain of insufficient heating output in winter or different air temperature from vents at same setting in regulated mode. Refer to A/C SYSTEM TEMPERATURE DOOR HEAT OUTPUT ACTIVATION, CHECKING .
Depending on vehicle equipment and on engine, heat insulation has been applied to coolant hoses, these must not be damaged and must be re-applied after installing.
-- Secure the wiring harness once again on the provided places and install the different air guides in reverse order.
-- Reinstall the instrument panel (refer to INSTRUMENT PANEL, INSTALLING ), the center console (CENTER CONSOLE, INSTALLING ), the glove compartment (GLOVE COMPARTMENT, INSTALLING ) , etc.
When installing the instrument panel, make sure that the "defrost" intermediate piece its properly on A/C unit and the defroster vent does not pinch the intermediate piece. Refer to OVERVIEW - AIR ROUTING AND AIR DISTRIBUTION IN PASSENGER COMPARTMENT .
On vehicles with a high voltage system (hybrid vehicles)
-- Visually inspect the high voltage components -D- and high voltage cables -E- after completing the work procedures and before installing the plenum chamber cover -B-. Refer to HIGH VOLTAGE SYSTEM GENERAL WARNINGS .
-- Electrical connections and routing. Refer to appropriate SYSTEM WIRING DIAGRAM.
-- Install the remaining removed parts in the opposite order.
-- Energize the power supply to the high voltage system. Refer to HIGH VOLTAGE SYSTEM, RE-ENERGIZING , also see HIGH VOLTAGE SYSTEM GENERAL WARNINGS .
Restart the high voltage system
Risk of electrocution
Death or serious bodily injury by electric shock
- The high voltage system may only be restarted by qualified personal (Audi high voltage technicians).
- Make sure the vehicle is energized using the "Guided Fault Finding " on the Vehicle Diagnostic Tester.
- The qualified personal (Audi high voltage technician) restarts the vehicle.
- The Audi high voltage technician should put a sign on the vehicle to identify it as a high voltage vehicle.
Restart 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 - High voltage restart
For vehicles without a high voltage system
-- Reconnect the Battery -A- ground connection; when doing this, pay attention to the notes regarding reconnecting the battery. Refer to BATTERY, DISCONNECTING AND CONNECTING or Battery -A- AND Auxiliary Battery -A1-, DISCONNECTING AND CONNECTING, VEHICLES WITH HIGH VOLTAGE SYSTEM .
-- Install the remaining removed parts in the opposite order.
All vehicles
-- Evacuate the refrigerant circuit and fill it. Refer to USING SERVICE STATION (Refrigerant R134a, Servicing; Refrigerant Circuit, Using Service Station).
-- Turn on the ignition.
-- Perform a basic setting and the output diagnostic test mode for the A/C system using the Vehicle Diagnostic Tester in the "Guided Fault Finding " function.
On this vehicle, the actuators are equipped with electronics. During the basic setting, a new actuator learns its position on the A/C unit and can then be activated by the Climatronic Control Module -J255- A/C display and control head (currently all actuators are identical) using the Vehicle Diagnostic Tester in the "Guided Fault Finding " function.
During the basic setting, the actuators are assigned and adapted corresponding to the switching sequence of the wiring. If this sequence does not conform the specification, the adjustment motors will adapt incorrectly and the door control will be wrong. Refer to MAIN WIRING DIAGRAM FOR A/C SYSTEM ACTUATORS (A/C system actuators block diagram).
-- Check the DTC memory for the Climatronic Control Module -- A/C display and control head and erase any displayed malfunctions, if necessary using the Vehicle Diagnostic Tester in the "Guided Fault Finding " function.
-- Operate the A/C system after filling the refrigerant circuit. Refer to A/C SYSTEM, STARTING OPERATION AFTER FILLING REFRIGERANT CIRCUIT .
Observe the information regarding operating the A/C system after filling. Refer to A/C SYSTEM, OPERATING AFTER CHARGING (Refrigerant R134a, Servicing; A/C System, General Information). After charging the A/C system before activating the A/C system.