General Information
Vehicles With A High Voltage System (Hybrid Vehicles)
Observe all of the additional warnings for all work performed on vehicles with 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.
Handling high voltage cables:
- 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.
- The round high voltage connectors are color coded with an external color ring and are mechanically coded using the guide- or code tabs. Always make certain that the coding matches when connecting the round connector in order to avoid any mechanical damage 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 Electrical 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 covers 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.
If it is necessary to perform work in the vicinity of high voltage components, perform a "visual inspection" of the high voltage components and cables for damage and follow the "general warnings when working on the high voltage system" .
If it is necessary to perform work on the high voltage components, disable the high voltage system and read and follow the "high voltage electrical system general warnings" .
- If it is suspected that chemicals were added to the refrigerant circuit to seal leaks, do not connect the A/C service station and do not extract the refrigerant.
- Chemicals that seal leaks in the coolant circuit form deposits that affect the function of the A/C system and lead to failure of the A/C system and the A/C service station.
- Remind the customer that the refrigerant circuit contains substances that VW has not approved. As such, the refrigerant circuit cannot be flushed. It is only possible to service the refrigerant circuit by replacing all the components which come in contact with this material.
VW does not approve the use of chemicals to seal leaks in the refrigerant circuit.
Chemicals used to seal leaks in the refrigerant circuit often react with air and the moisture in it. They cause deposits in the refrigerant circuit and the A/C service station and malfunctions in valves and other components that they come in contact with. These deposits cannot be removed completely from the components, even by flushing. It is only possible to service the refrigerant circuit by replacing all the components which come in contact with this material.
Chemicals used to seal leaks in the refrigerant circuit usually cannot be detected from outside. The label that should be applied to identify it is often missing. Therefore be careful when working with if you do not know its service history.
- Refrigerant circuit must be flushed with refrigerant R134a in order to force out contaminants (e.g. abraded material from a malfunctioning A/C compressor) as well as old refrigerant oil as efficiently and as cleanly as possible and without the need for extensive work.
For vehicles with an electrically-driven A/C compressor, pay attention to the notes for replacing the Electrical A/C Compressor -V470-. If there is damage on the A/C compressor electronics, the refrigerant circuit must not always be cleaned, refer to FLUSHING NOT NECESSARY .
The refrigerant circuit should be flushed with refrigerant R134a if:
- dirt or other contamination is in the refrigerant circuit.
- vacuum reading is not maintained on evacuating a leak-free refrigerant circuit (pressure build-up due to moisture in refrigerant circuit).
- refrigerant circuit has been left open for longer than normal (e.g. following an accident).
- If pressure and temperature measurements in the refrigerant circuit indicate the likelihood of moisture in the circuit.
- In the event of doubt about the amount of refrigerant oil in the circuit. If the A/C compressor should be reinstalled, the refrigerant should be drained from the compressor via the oil drain plug. To facilitate this, the ribbed belt pulley or magnetic clutch plate on the A/C compressor should be rotated by hand. After flushing, the entire quantity of refrigerant oil specified by vehicle-specific Repair Information should be added to the refrigerant circuit (50 grams directly in the A/C compressor). Note additional oil quantity for systems with a second evaporator.
- A/C compressor had to be replaced on account of internal damage (e.g. noise or no output).
- stipulated by the vehicle-specific Repair Information following replacement of certain components.
- Another compressor with different refrigerant oil should be installed.
Tools Required
- A/C Service Station with Flushing Device VAS 6381 or Air Conditioning Flush Tool VAS 6337. The auxiliary function "Flush refrigerant circuit" and the refrigerant circuit flushing device required for it are present on these A/C service stations .
- Refrigerant Circuits Adapter Set 1 VAS 6338/1, refer to ADAPTER FOR ASSEMBLING FLUSHING CIRCUIT
- Refrigerant Circuits Adapter Set 2 VAS 6338/50, refer to ADAPTER FOR ASSEMBLING FLUSHING CIRCUIT .
If neither of the two A/C service stations listed above are available for use in the workshop, A/C Service Station with Flushing Device VAS 6336/1 or Air Conditioning Flush Tool VAS 6337/1 (depending on the workshop A/C service station version) (min. 7 kg refrigerant R134a in refrigerant bottle) can also be used to flush the refrigerant circuit. However, the flushing procedure must then be performed manually, refer to GENERAL INFORMATION .
In vehicles with screw-connections on refrigerant circuit, A/C Adapter Set - Adapter 1 VAG 1785/1 through A/C Adapter Set - Adapter 2 VAG 1785/8 from the Refrigerant Circuits Adapter Set 1 VAS 6338/1 or Refrigerant Circuits Adapter Set 2 VAS 6338/50 may be used. In vehicles with screw-connections on A/C compressor and on accumulator, two of the A/C Adapter Set - Adapters 8 VAG 1785/8 are required.
A Refrigerant Circuits Adapter Set 2 - Adapter 31 VAS 6338/31 with 5/8 -18 UNF connections and large internal diameter can be found in the adapter chests in order to be able to bridge components (it is commercially available).
Preliminary Work
-- Discharge refrigerant circuit, refer to DISCHARGE REFRIGERANT CIRCUIT WITH A/C SERVICE STATION .
-- Remove A/C compressor, refer to A/C COMPRESSOR .
On a vehicle with restrictor and reservoir.
-- Remove restrictor (specific to vehicle) and reconnect refrigerant pipes to each other.
-- Remove reservoir (specific to vehicle), refer to Heating, Ventilation & Air Conditioning and connect refrigerant pipes to each other (to do this, use adapter and Refrigerant Circuits Adapter Set 1 - Adapter 31 VAS 6338/31) from Refrigerant Circuits Adapter Set 1 VAS 6338/1, refer to ADAPTER FOR ASSEMBLING FLUSHING CIRCUIT .
The reservoir could be flushed, but it requires too much refrigerant due to its large volume. When this refrigerant is extracted, the reservoir ices up severely and this prolongs the extraction process significantly.
On a vehicle with expansion valve and receiver/dryer.
-- Remove receiver/dryer, refer to Heating, Ventilation & Air Conditioning (specific to vehicle, not required for all vehicles) and connect refrigerant pipes to each other (for this, use adapters and Refrigerant Circuits Adapter Set 1 - Adapter 31 VAS 6338/31), refer to ADAPTER FOR ASSEMBLING FLUSHING CIRCUIT .
-- Remove expansion valve, refer to Heating, Ventilation & Air Conditioning (specific to vehicle) and install the adapter for it, refer to ADAPTER FOR ASSEMBLING FLUSHING CIRCUIT .