REAR HEATING AND A/C SYSTEM, INCORPORATION IN THE COOLANT CIRCUIT, "High" A/C SYSTEM

• The arrows show the coolant flow direction.

Courtesy of AUDI OF AMERICA, LLC

1. Pass-Through for Coolant Lines through the Lower Plenum Chamber Bulkhead
2. Coolant Return to Engine
   • Integration of heating and A/C system into the engine coolant circuit. Refer to INCORPORATION OF FRONT HEATING AND A/C SYSTEM INTO COOLANT CIRCUIT, VEHICLES WITHOUT A HIGH-VOLTAGE SYSTEM AND PARKING HEATER  and CONNECTION DIAGRAM - COOLANT HOSES .
3. Coolant Supply from Engine
   • Integration of heating and A/C system into the engine coolant circuit. Refer to INCORPORATION OF FRONT HEATING AND A/C SYSTEM INTO COOLANT CIRCUIT, VEHICLES WITHOUT A HIGH-VOLTAGE SYSTEM AND PARKING HEATER  and CONNECTION DIAGRAM - COOLANT HOSES .
4. Coolant Hose, "Return"
   • Coolant Return to Engine
   • In plenum chamber
5. Bleed Screw in the "Supply" Coolant Hose
   • Coolant Supply from Engine
   • In plenum chamber
   • Bleeding. Refer to COOLANT CIRCUIT, BLEEDING .
6. Front Heater and A/C Unit
   • Heat exchanger, removing and Installing with the heater and A/C unit installed. Refer to HEATER CORE, REMOVING AND INSTALLING .
   • Heat exchanger, removing and Installing with the heater and A/C unit removed. Refer to OVERVIEW - HEATER AND A/C UNIT .
7. Coolant Lines and Coolant Hoses from the Heater Core Inside the Rear Heater and A/C Unit
   • In plenum chamber
   • Return from the rear heater and A/C unit to the engine
8. Coolant Lines and Coolant Hoses to the Heater Core from the Heater Core inside the Rear Heater and A/C Unit
   • In the plenum chamber, in the right wheel housing and on the underbody
   • Supply from engine to the rear heater and A/C unit
   • Pay attention to the correct routing, securing and incorporation of the coolant pipes and coolant hoses from the openings of the plenum chamber other the area under the right fender and on the underbody of the vehicle to the heat exchanger in the rear heater and A/C unit.
9. Coolant Lines and Coolant Hoses to the Heater Core from the Heater Core inside the Rear Heater and A/C Unit
   • In the right wheel housing and on the underbody
   • Return from the rear heater and A/C unit to the engine
   • Pay attention to the correct routing, securing and incorporation of the coolant pipes and coolant hoses from the openings of the plenum chamber other the area under the right fender and on the underbody of the vehicle to the heat exchanger in the rear heater and A/C unit.
10. Openings in the Area under the Right Fender for the Coolant Lines
    • Pay attention to the correct routing, securing and incorporation of the coolant pipes and coolant hoses from the openings of the plenum chamber other the area under the right fender and on the underbody of the vehicle to the heat exchanger in the rear heater and A/C unit.
11. Rear Heater and A/C Unit with Heater Core
    • To the coolant pipes to the heater core on the rear heater and A/C unit (in the passenger compartment).
    • The coolant pipes to the heat exchanger, via which the coolant hoses are connected are a component of the rear heater and A/C unit.
    • For the refrigerant lines to be removed, the right aerodynamic underbody trim and the heat shield in the center tunnel must first be removed. Refer to COMPONENT LOCATION OVERVIEW - HEAT SHIELD .
    • For the coolant lines to the heat exchanger to be removed, the air duct to the Rear Fresh Air Blower -V80- and the heat shield in the center tunnel must be removed. Refer to Rear Fresh Air Blower -V80-, REMOVING AND INSTALLING  and COMPONENT LOCATION OVERVIEW - HEAT SHIELD .
    • The coolant lines to the heater core in the rear heater and A/C unit are connected via coolant hoses, which are routed in the center tunnel above the driveshaft over the heat shield, to the coolant circuit.
    • To remove the heat shield in the center tunnel, the exhaust system with the center muffler and the driveshaft must also be removed depending on the vehicle. Refer to the appropriate service information .