A/C Unit
A/C Unit
Special tools, testers and auxiliary items required
• Hose Clamps up to 25 mm Diameter (3094)
• Engine Bung Set (VAS 6122)
• Hose Clamp Pliers (VAS 6362)
Removal
There is a risk of scalding from hot steam and coolant.
• The coolant system is under pressure when the engine is warm.
• To reduce the pressure, cover the coolant reservoir cap with several cloths and then open it carefully.
- Open the coolant reservoir cap - arrow -.
- Drain the refrigerant circuit.
- Remove the tower brace.
- Cover the area beneath the connections for the coolant hoses in the plenum chamber, for example, with absorbent paper.
- Label the arrangement of the coolant hoses.
• So that no coolant enters the plenum chamber when removing the coolant hoses, hold a container under the particular coolant hose.
- Clamp off the coolant hoses - 1, 4 - with hose clamps (3094) and remove from the heater core by releasing the hose clips - 2, 3 -.
- Attach a short hose - A, C - to both connections.
• Insert the compressed air gun - D - into the end of a hose.
- Hold the container - B - under the second hose and use the compressed air gun to carefully blow the coolant out of the heater core.
- Detach the grommet - 3 - from the plenum chamber bulkhead mount - 2 - and remove from the connections - 1 - for the heater core.
- Remove the expansion valve. Refer to => [ Expansion Valve ] Expansion Valve.
- Remove the retaining plate - A - from the refrigerant lines - B, C -.
- Coat the support ring - E - with lubricant and pry it forward out of the mount.
- Detach the grommet - D - to the A/C unit from the plenum chamber bulkhead mount.
Risk of damaging the grommet.
• The grommet is connected to the A/C unit and can only be removed after the A/C unit is disassembled.
- Remove the instrument panel.
- Remove the air intake housing. Refer to => [ Air Intake Housing ] Air Intake Housing.
- Unscrew the nuts - 2 - and remove the ground wire - 1 -.
- Disconnect the electrical harness connector - 3 - by releasing the retaining tab - 4 -.
- Remove the air guide - 2 - in an upward direction.
- Expose the wiring harness - 1 -.
- Disconnect the electrical harness connector on the Right vent temperature sensor (G151).
- Unscrew the screw - 3 - from the expanding clip.
- Remove the air guide of the instrument panel vent - 1 -.
- Remove the central tube.
- Remove the rear air guide channel. Refer to => [ Rear Air Guide Channel ] Rear Air Guide Channel.
- Remove the condensation water drain hose - 1 - on the left and right from the A/C unit connection - 2 -.
- Unscrew the screw - 3 - and tilt the tab - 4 - in the - direction of the arrow - to release it.
- Remove the air guide channel - 1, 3 - for the rear footwell vent at the air distributor housing - 2 - and tilt to the side - arrows -.
- Pull the air distributor housing slightly backward and remove toward the right.
Installation
Installation is done is reverse order, observe the following:
• Before installing, check all gaskets and seals on the A/C unit for damage and replace if necessary.
- Install the support ring - E - in the grommet - D -.
• The brace at the support ring must point outward.
- Coat the grommet with lubricant.
- Install the A/C unit and attach the central tube on the left and right to the mount.
- Manually tighten the A/C unit all the way to the central tube.
- Insert the grommet in the plenum chamber bulkhead.
• Check the evaporator grommet on the plenum chamber bulkhead pass-through for proper seating.
• Water penetration into the passenger compartment if the grommet is damaged or not installed correctly.
- Install the retaining plate - A - on the refrigerant lines - B, C -.
- Install the expansion valve. Refer to => [ Expansion Valve ] Expansion Valve.
- Push the grommet - 3 - over the connections - 1 - for the heater core and insert in the plenum chamber bulkhead - 2 -.
• Check the heater core grommet on the plenum chamber bulkhead pass-through for proper seating.
• Water penetration into the passenger compartment if the grommet is damaged or not installed correctly.
- Install the condensation water drain hose. Refer to => [ Condensation Water Drain Hose ] Service and Repair.
- Push the tab - 3 - in the - direction of the arrow A - to the stop and then tilt upward - arrow B -.
• The tab must clearly engage in the ribs - 4 - on the A/C unit - 1 -.
- Tighten the screw - 2 -.
- Install the central tube.
- Install the air intake housing. Refer to => [ Air Intake Housing ] Air Intake Housing.
- Install the rear air guide channel. Refer to => [ Rear Air Guide Channel ] Rear Air Guide Channel.
- Install the rear footwell vent air guide channel. Refer to => [ Rear Air Guide Channel/Footwell Vent on Left and Right ] Rear Air Guide Channel/Footwell Vent on Left and Right.
- Install the front passenger instrument panel vent air guide. Refer to => [ Right Instrument Panel Vent Air Guide - Front Passenger Side ] Right Instrument Panel Vent Air Guide - Front Passenger Side.
- Install the tower brace.
- Evacuate and fill the refrigerant circuit.
After completion of the repair work, perform the following work on the control head using the Vehicle Diagnostic Tester in the "Guided Fault Finding" function:
- Read out the event memory and erase any displayed entries.
- Perform the basic setting.
- Perform the output diagnostic test mode.
- Operate the A/C system after filling the refrigerant circuit. Refer to => [ A/C System, Operating After Filling Refrigerant Circuit ] A/C System, Operating After Filling Refrigerant Circuit.
- Check the function of the A/C system and the flow direction and distribution of the air flowing out of the defroster vent to the windshield.
- Check the air flow direction, depending on the switch position.