Housing Assembly HVAC: Service and Repair
Installing and removing the heating/air-conditioning unit
Removal
1. Remove the covers over the heating/air-conditioning system, battery and fluid tank. Disconnect and remove the battery.
2. Remove refrigerant by suction using the service unit.
3. Detach the air-conditioning lines at the expansion valve. Close the connections and lines with plugs immediately so that they are air-tight.
4. Remove the steering wheel and loosen the steering column panel. Observe the safety regulations for handling airbag units.
5. Undo the central screw (clamp) on the steering column switch from below and pull it forwards slightly. Remove the cover at the top and disconnect the electrical plug connections. Remove the steering column switch.
6. Detach the instrument panel and unclip the right side upwards. Disconnect the electrical plug connections.
7. Remove the steering column cover (4 screws).
8. Remove the radio and heating/air-conditioning controller. Unclip the switch panel on the left and on the right. Disconnect the electrical plug connections. Undo the retaining frame in the center and remove it.
9. Remove the left side nozzle and disconnect the electrical plug connection. Unclip and remove the sun sensor cover and defrost panel.
10. Undo the interior monitoring system and disconnect the electrical plug connection.
11. Remove the air guide at the bottom right. Remove the passenger's airbag unit. Observe the safety regulations for handling airbag units.
12. Remove the front cover of the center console. Undo the fuse holder and diagnosis plug in the left footwell.
13. Undo the control panel at the bottom, center, left and right. Carefully remove the control panel and detach the loudspeaker cable.
14. Undo the center tunnel support on the support frame at the top and on the tunnel holder at the bottom.
15. Remove the left air guide. Only loosen the defrost channel. Undo and remove the center air distributor casing.
16. Disconnect the central plug connections (2 ea.) from the heater/air-conditioning unit.
17. Disconnect the battery positive terminal on the current distributor and the current distributor on the cover front wall.
18. Disconnect both heating hoses upstream of the heat exchanger with the standard hose clamp. Disconnect the heating hoses on the heat exchanger and plug the connections.
19. Undo the heater/air-conditioning unit on the lid firewall (3 nuts). Pull off the water drainage hose from the heater/air-conditioning unit.
20. Undo the holder of the heater/air-conditioning unit from the passenger's side at the top right.
21. Carefully lower and remove the heater/air-conditioning unit downwards into the footwell. Do not damage the electrical plug connections or cables.
Installation
1. Ensure that the air distributor casing and air guides are correctly positioned. Engage the electrical plug connections and carefully lay the electrical cables (do not pinch).
2. Observe the safety regulations for handling airbag units.
3. Set the steering column switch:
Use a depth gauge to measure between the end of the steering axle and the metal cover of the steering column switch.
Adjustment dimension 55 ± 0.5 mm
4. Replace the seal between the current distributor and firewall if necessary. After fitting the current distributor on the firewall (tightening torque 15 Nm), tighten the battery cable with a new M8 hexagon nut. Tightening torque: 15 Nm (11 ft lb).
5. Replace the O-rings for the refrigerant lines at the expansion valve and wet the new O-rings with refrigerant oil.
NOTE: If the heating/air-conditioning unit is replaced, the refrigerant oil in the evaporator must be topped up. Determine the quantity of the refrigerant oil and top up again with refrigerant oil (volume removed by suction + 20 cubic cm).
Refrigerant oil removed by suction from a previously run air-conditioning system may no longer be used (special-category waste).
6. The heat exchanger is connected to the engine-cooling system, and coolant flows through it when the engine is running. The cooling system must be bled after removal or installation of the the heater/air-conditioning unit.