Rear Expansion Valve, Removing And Installing

• For all the following work, close the open lines and connections with clean plugs from the Engine Bung Set: VAS6122  .

Remove the refrigerant lines

-- Switch off the ignition.

-- Discharge the refrigerant circuit. Refer to Refrigerant Circuit (R134a) or Working with A/C Service Station (R1234ya) (1 of 2) or Working with A/C Service Station (R1234yf) (2 of 2) .

-- Remove the left underbody trim panel. Refer to COMPONENT LOCATION OVERVIEW - UNDERBODY TRIM PANELS .

-- Remove the heat shield for the transmission tunnel. Refer to COMPONENT LOCATION OVERVIEW - HEAT SHIELD .

-- Loosen the heat shield mat on the left center tunnel in the area of the transmission from the vehicle.

-- Loosen the bracket for the refrigerant lines from the underbody. Refer to OVERVIEW - EXPANSION VALVE AND REFRIGERANT LINES TO THE REAR HEATER AND A/C UNIT, VEHICLES WITH "High A/C System" .

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-- Remove the nut -A-.

-- Remove the refrigerant lines -B- and -C- from the expansion valve -D-.

-- Remove the bolts -A-.

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-- Remove the expansion valve -B- from refrigerant lines -C- and -D- (to the evaporator in the rear heater and A/C unit).

Installing 

Install in reverse order of removal and note the following:

-- Clean refrigerant line connections on expansion valve -B- and on refrigerant lines -C- and -D-, and check for damage.

-- Replace the O-rings -E- and -F-. Refer to the Parts Information for the correct version.

-- Coat the O-rings -E- and -F- with refrigerant oil before installing. Refer to REFRIGERANT CIRCUIT SEALS .

-- Ensure that the O-ring seals -E- and -F- are properly seated on the connections of refrigerant lines -C- and -D- to the evaporator.

-- Ensure that the retaining plate -G- is seated properly on refrigerant lines -C- and -D-.

-- Place expansion valve -B- on the refrigerant line connections -C- and -D-.

-- Install the bolts -A-.

-- Clean refrigerant line connections on refrigerant lines -B- and -C-, and check for damage.

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-- Replace the O-ring seals -E- and -F- and lightly coat with refrigerant oil before installing. Refer to REFRIGERANT CIRCUIT SEALS and to the Parts Information for different versions.

-- Check the O-rings -E- and -F- in the groove of the connections for correct seating.

• Install the refrigerant lines stress-free.

-- Insert refrigerant lines -B- and -C- on expansion valve.

-- Screw in the nut -A-.

-- Check the routing of the refrigerant lines after attachment. They must be inserted in the provided brackets in a tension-free manner and must not come in contact with other components.

-- Evacuate and charge the refrigerant circuit. Refer to Refrigerant Circuit (R134a) or Working with A/C Service Station (R1234ya) (1 of 2) or Working with A/C Service Station (R1234yf) (2 of 2) .

-- Install the remaining removed components.

-- Switch the ignition on.

-- On vehicles with a high-voltage system (Audi Q7 e-tron), initiate the basic setting of the A/C system through the Thermal Management Control Module -J1024- and activate the power-controlled valves using one of the routines stored there. "Charge/flush the refrigerant circuit stop routine" using the Vehicle Diagnostic Tester in the "Guided Fault Finding"  function.

-- Check the DTC memory for the Front A/C Display Control Head -E87- and, if necessary, delete any displayed errors using the Vehicle Diagnostic Tester in the "Guided Fault Finding"  function.

-- Start the A/C system after charging the refrigerant circuit. Refer to A/C SYSTEM, STARTING AFTER CHARGING REFRIGERANT CIRCUIT .

Tightening Specifications 

• Refer to OVERVIEW - EXPANSION VALVE AND REFRIGERANT LINES TO THE REAR HEATER AND A/C UNIT, VEHICLES WITH "High A/C System" 
• Refer to COMPONENT LOCATION OVERVIEW - UNDERBODY TRIM PANELS .
• Refer to COMPONENT LOCATION OVERVIEW - HEAT SHIELD .