4-Cylinder Engine
A/C Compressor Refrigerant Lines
• An A/C compressor with an A/C clutch (N25) is installed as a running change on certain 4 cylinder vehicles from MY 12. Refer to => [ Belt Pulley with A/C Clutch (N25) Overview ] Belt Pulley With A/C Clutch (N25) Overview. The A/C clutch turns off the A/C compressor drive completely under certain conditions (for example "ECON"). The correct Climatronic control module (J255) must be installed and it must be coded correctly so that the Climatronic control module can control the A/C clutch. Refer to the Parts Catalog and to the Vehicle diagnostic tester in "Guided Fault Finding".
• The A/C compressor without an A/C clutch (N25) is always also driven when the engine is running. If the vehicle has an A/C compressor without an A/C clutch, then the vehicle may only be started when the refrigerant circuit has been properly assembled. For example; if the refrigerant lines are not connected to A/C compressor, when the engine is running the A/C compressor may heat up (via internal heat generation) so much that the A/C compressor will be damaged. Such internal heat generation results from the fact that - even with delivery near 0% - the compressor is confronted with a fixed resistance (sealed circuit).
• Close open lines and connections on A/C compressor using suitable caps (to prevent possible penetration of dirt and moisture).
- Turn off the ignition.
- Drain the refrigerant circuit.
• Depending on the allocation of the service connection an on the refrigerant line, and on the version of the vehicle, it may be necessary to remove the additional reinforcement on the left suspension strut dome so that the service coupling of the service station can be connected (for example, on the Audi Q5).
With high voltage systems (hybrid vehicles)
Read and follow all of the supplemental warnings for all work performed on vehicles with the high voltage system.
If it is necessary for the following procedure to perform work in the vicinity of high voltage components, perform a visual inspection of the high voltage components and cables for damages, refer to => [ Visual Inspection of High-Voltage Components and Cables for Damage ] Visual Inspection of High-Voltage Components and Cables For Damage and always follow the warnings when working on the high voltage system.
Risk of unintended engine start
The ignition must be turned off and the ignition key must remain outside of the vehicle when working on vehicles with a high voltage system.
How to handle high voltage cable:
• Do not stand on or place tools on high voltage cables and their components as it may damage the cable insulation.
• Never bend or kink high voltage cables forcefully as it may damage the cable insulation.
• Color-code the round high voltage connector with an external color ring and code them mechanically using the guide- or code tabs. Always make certain that the coding matches when connecting the round connector in order to avoid mechanically damaging the high voltage connector.
There is a risk of electrocution from damaged high voltage components
Observe the following when working around high voltage components and high voltage wires:
• Never work around high voltage components and cables with cutting, deformed, or sharp edged tools, or heat sources such as welding or soldering tools, heated air, and thermal glue.
• Inspect the high voltage components visually before beginning.
• Perform a visual inspection of the electric drive power and control electronics (JX1) , the electro-drive drive motor (V141) , the A/C compressor (V470) and the high voltage lines when working in the engine compartment.
• Perform a visual inspection of the high voltage lines and the cover when working on the underbody.
• Perform a visual inspection of the high voltage lines and the Electrobox with the high voltage system maintenance connector (TW) when working in the luggage compartment.
• Perform a visual inspection on all of the potential equalization cables.
Observe the following items when performing the visual inspection:
• The components do not display any signs of external damage.
• The high voltage cable insulation and the potential equalization cables are not damaged.
• The high voltage cables do not display any abnormal deformations.
• Every high voltage component is marked with a red warning label.
- Remove the bolts - 1 - and - 4 -.
- Remove the refrigerant pipes.
For vehicles without a high voltage system
• On vehicles with a 4 cylinder engine, it is not always necessary to remove the A/C compressor from the bracket in order to remove the refrigerant lines. Depending on the style of the power steering vane pump, the refrigerant lines can be removed from the A/C compressor also when the A/C compressor is removed from the bracket.
• The power steering pump is installed only on vehicles with electro-mechanical power steering.
• For vehicles with 4 cylinders, if the bolt on the connection for the refrigerant lines on the A/C compressor is not accessible, remove the A/C compressor from the bracket. Refer to => [ A/C Compressor Removing from Bracket ] A/C Compressor Removing From Bracket.
• If the refrigerant line on the low pressure side is removed (from the refrigerant line with the inner heat exchanger to the compressor), then the components, which must be removed, depend on the routing of the refrigerant line.
- Remove the screws - A -.
- Remove the refrigerant lines - B - and - C -.
All vehicles
Risk of damaging refrigerant lines and hoses.
• Do not stretch, kink or bend refrigerant lines and hoses.
• Seal open pipes and connections on the A/C compressor with caps (to prevent dirt and moisture from getting in).
Installing
Installation is the reverse of removal, noting the following:
- Replace O-rings seals - D - and - E -, version. Refer to Electronic Parts Catalog (ETKA).
- Check the guide ring - F - on the connections for both refrigerant lines - B - and - C - for damage.
- Clean the refrigerant line and A/C compressor connections and check for damage.
- Coat the O-ring seals with refrigerant oil prior to installation. Refer to => [ Refrigerant Circuit O-rings ] Refrigerant Circuit O-Rings.
- Insert the respective O-ring - D - and - E - in the groove - G - on the connections for both refrigerant lines - B - and - C -.
• Do not use the O-rings from the sealing caps that are installed on the connections in the replacement compressor when installing the lines.
• Make sure the O-rings fit correctly inside the groove - G - on each refrigerant line.
- Insert both refrigerant lines - B - and - C - into each connection on the A/C compressor.
- Tighten the bolts - A - to 9 Nm (bolts with a M6 thread) and to 25 Nm (bolts with a M8 thread).
• Following attachment of refrigerant pipes to A/C compressor (and installation of the A/C compressor) check routing of pipes. They must be inserted in holders provided and not make contact with other components.
- Evacuate and fill the refrigerant circuit.
- Install the remaining removed components.
- Switch on the ignition.
- Check the Climatronic control module (J255) DTC memory and erase any displayed malfunctions if necessary. Refer to the Vehicle diagnostic tester in "Guided Fault Finding".
- 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.
• Note the information regarding operating the A/C system after filling.