Refrigerant Circuit, Charging

WARNING: This page is about a different car, the 2022 Volkswagen ID.4 and 2021 Volkswagen ID.4. However, it is still accessible from the selected car via links, so may be relevant.

Special tools and workshop equipment required

Air Conditioning Service Unit R744 :VAS581009

-- Use the Vehicle Diagnostic Tester to perform the function "Refrigerant circuit, charging/evacuating/flushing".

The Vehicle Diagnostic Tester must not be disconnected from the vehicle during this process.
It is absolutely necessary to perform the "Refrigerant circuit, charging/evacuating/flushing" function with the Vehicle Diagnostic Tester so that all of the refrigerant circuit valves are opened. Only then can the entire circuit be evacuated, charged or flushed.

Refrigerant and refrigerant oil capacities. Refer to Technical Data (vehicle-specific Service Information).
Perform the procedure as described in the A/C Service Station Owner's Manual. Refer to A/C Service Station Owner's Manual.
Before adding the refrigerant, correct the quantity of refrigerant oil. Refer to Technical Data (vehicle-specific Service Information).
Depending on the version of the A/C Service Station and the density of the refrigerant in the canister, the refrigerant circuit may not always be filled with the designated refrigerant quantity. Therefore, check the amount of refrigerant in the canister before starting any work. Refer to the A/C Service Station Operating Instructions.
Make sure the A/C Service Station is on the same level as the vehicle whose refrigerant circuit is to be charged (maximum difference 50 cm) when charging the refrigerant circuit. If a difference in height is too large, a difference between the amount of refrigerant displayed on the service station and the actual amount filled in the circuit may result (depending on the version of the A/C Service Station). The filling precision of the A/C Service Station may change.
The refrigerant circuit is completely assembled. Refer to Refrigerant Circuit (vehicle-specific Service Information).

-- Deactivate drive ready mode and switch off all electrical equipment.

-- Connect the A/C Service Station to the power supply.

-- Check the amount of refrigerant and refrigerant oil in the A/C Service Station and refill if necessary. Refer to the A/C Service Station Operating Instructions.

NOTE:

The cylinder must be filled with at least 20 % of the designated fill capacity when delivered, unrelated to the version of the A/C Service Station. A R744 cylinder can not be emptied completely, but only by approximately 90% when filling the refrigerant circuit of the vehicle. This is also true when the refrigerant is drawn in via the vehicle A/C compressor for an A/C Service Station without an inner pressure reservoir. Refer to the A/C Service Station Operating Instructions.

The density of a new canister is approximately 750 g (26.5 oz)/Liter internal volume. The density of the cylinder at the end of the filling process must exceed the designated density in the vehicle by a certain amount that the refrigerant R744 flows from a cylinder of a A/C Service Station without inner pressure reservoir into the refrigerant circuit of the vehicle. If the density of the cylinder comes close to the density of the refrigerant circuit in the vehicle, then no refrigerant is flowing into the refrigerant circuit of the vehicle anymore.

-- Start the A/C Service Station according to its operating instructions. Refer to the A/C Service Station Operating Instructions.

-- Remove the caps from the refrigerant circuit service connections (refer to the vehicle-specific refrigerant circuit). Refer to Refrigerant Circuit (vehicle-specific Service Information).

-- Check the refrigerant circuit service connections for debris and corrosion and if necessary clean.

Dirt or a rough surface on the service connections due to corrosion can cause seal damage, which can then cause premature failure of the quick-release couplings.

-- Connect the quick-release couplings to the refrigerant circuit service connections. Refer to A/C SERVICE STATION ON REFRIGERANT CIRCUIT, CONNECTING .

-- Evacuate the refrigerant circuit using the A/C Service Station. Refer to REFRIGERANT CIRCUIT, EVACUATING .

CAUTION:

Risk of damaging the A/C compressor by the refrigerant circuit vacuum.

- Never start the engine with vacuum in the refrigerant circuit.

-- Charge the refrigerant circuit via the low-pressure side.

-- Set the designated refrigerant quantity on the A/C Service Station. Refer to the A/C Service Station Operating Instructions and Technical Data (vehicle-specific Service Information).

-- Adjust on the A/C Service Station that the refrigerant will be filled on the low-pressure side. Refer to the A/C Service Station Owner's Manual.

-- Charge the refrigerant circuit with the designated refrigerant quantity; to do so, follow the instructions for the A/C Service Station. Refer to the A/C Service Station Operating Instructions.

Before completely charging the refrigerant circuit, it is pre-filled for a subsequent pressure test. Here it is checked if there are any major leaks in the refrigerant circuit. If this pressure test is not OK. Refer to LEAKS, FINDING .

With this function, the A/C Service Station valves on the high-pressure side are closed and the valves on the low-pressure side are activated so that the refrigerant from the canister can be added to the vehicle refrigerant circuit on the low-pressure side.

-- Disconnect the A/C Service Station from the refrigerant circuit and turn it off. Refer to A/C SERVICE STATION, SWITCHING OFF AND DISCONNECTING FROM REFRIGERANT CIRCUIT .