Working On Refrigerant Circuit
Work on refrigerant circuit should only be performed in a ventilated rooms (workshops). Ensure that there are no workshop pits, basement staircases or shafts within a five meter circumference. Extraction systems are to be switched on. Note the information in the refrigerant-specific service information. Refer to A/C SYSTEM, GENERAL INFORMATION and REPAIR INFORMATION
Reason:
The refrigerant coming out is not only colorless and odorless, but also heavier than air and thus displaces oxygen. If refrigerant gas still escapes even though all the safety precautions have been followed, there is a risk of suffocating in poorly ventilated areas and in workshop pits - even if the asphyxiation hazard is not noticeable.
Never weld or hard/soft solder components of a filled A/C system. This also applies to welding and soldering on the vehicle, if there is a risk that it may heat up components in the A/C system.
Reason:
Exposure to heat creates considerable pressure in the system, which could cause it to burst.
Corrective Measure:
Discharge the refrigerant circuit.
When servicing the A/C system, all open components and line connections are to be immediately re-sealed.
Reason:
Moisture will penetrate into A/C system components if they are left open for a lengthy period. If this is the case, air conditioners cannot be refilled without having to replace parts of the system.
- Information about procedures using the A/C Service Station on vehicles with A/C. Refer to WORKING WITH A/C SERVICE STATION , REFRIGERANT CIRCUIT .
Vehicles with high-voltage system (Audi Q7 e-tron)
To discharge, evacuate, and charge the refrigerant circuit, then the electrically-operated valves installed in the refrigerant circuit on a vehicle with a high-voltage system must be open. Activate and open the valves through a routine stored in the Thermal Management Control Module -J1024- using the Vehicle Diagnostic Tester in the "Guided Fault Finding " function.
-- Initiate the A/C system basic setting through the Thermal Management Control Module -J1024- and open the power-activated valves through the stored routine "Extract, evacuate and fill the refrigerant circuit" using the Vehicle Diagnostic Tester in the "Guided Fault Finding " function.
Reason:
Different power-operated valves and check valves are installed in the refrigerant circuit. Depending on the last operating condition of the A/C system (cooling the vehicle interior, cooling the high-voltage system components or heat pump operation), the power-operated valves are opened or closed. If more than one power-operated valve is closed, the refrigerant circuit may no longer be completely empty, evacuated or filled. Refer to SYSTEM OVERVIEW - REFRIGERANT CIRCUIT ON VEHICLES WITH HIGH-VOLTAGE SYSTEM (AUDI Q7 E-TRON) and use the Vehicle Diagnostic Tester in the "Guided Fault Finding " function.