A/C Unit With Coolant Lines

A/C Unit with Coolant Lines

CAUTION!
There is a risk of burns.

• The heat regulating valve unit may be warn or hot even when the engine is cold because it is continuously activated when the ignition is on depending on the temperature setting on the Climatronic Control Module (J255).

• Make sure the valves on the heat regulating valve unit are connected correctly (Left Heat Regulating Valve (N175) and Right Heat Regulating Valve (N176)). If the connectors on the coolant circuit or the electrical wires are switched with one another, the Climatronic Control Module (J255) cannot regulate properly.

• If the Coolant Pump (V50) makes noise, check the coolant system to make sure it is bled completely (air in the circuit can cause noise) and the A/C unit to make sure it is integrated correctly in the coolant circuit before removing the heat regulating valve unit or the coolant pump.

• Both heat regulating valves are open without current. If the voltage supply or the connecting to the Climatronic control module are interrupted, the A/C system heat output may not be regulated correctly (the A/C system heats constantly).





1 Heater Unit Heat Exchanger

• The heat exchanger is divided in the center (driver and passenger side).

• Removing and installing, refer to => [ A/C Unit Heat Exchanger ] A/C Unit Heat Exchanger.

2 Coolant Supply Pipe To The Heat Exchanger (Driver Side)

3 Coolant Return Pipe From The Heat Exchanger

4 Coolant Supply Pipe To The Heat Exchanger (Passenger Side)

5 Line Connection

• With supply and return lines.

• Leads from the passenger compartment under the center tunnel.

6 Rubber Grommet

• For the opening for connecting the lines - item 5 - in the center tunnel.

7 Coolant Hose

• Return for coolant from A/C unit heat exchanger to the engine.

8 Coolant Pipe

• Return for coolant from A/C unit heat exchanger to the engine.

• With a bypass to the coolant supply.

9 Coolant Hose

• Coolant supply from the right heat regulating valve.

• To the passenger side heat exchanger.

10 Coolant Pump (V50)

• Removing and installing, refer to => [ Coolant Pump ] Coolant Pump.

11 Coolant Hose

• Coolant supply from the engine to the coolant pump.

12 Coolant Hose

• Coolant supply from the coolant pump.

• To the bypass - item 13 -.

13 Bypass

• Between the heat exchanger supply and return.

• On the coolant pipe - item 8 -.

14 Coolant Hose

• Coolant supply to the heat regulating valve unit.

• From the bypass - item 13 -.

15 Coolant Hose

• Coolant supply from the left heat regulating valve.

• To the driver side heat exchanger.

16 Heat Regulating Valve Unit

• With the Left Heat Regulating Valve (N175) and Right Heat Regulating Valve (N176)

• Removing and installing, refer to => [ Left and Right Heat Regulating Valves ] Service and Repair.