Electrically-Driven A/C Compressor

WARNING: This page is about a different car, the 2023 Audi SQ8, 2023 Audi RS Q8, and 2023 Audi Q8. However, it is still accessible from the selected car via links, so may be relevant.

Vehicles with a High-Voltage System (Hybrid Vehicles)

If procedures are necessary near the high-voltage system components, "visually inspect the high-voltage components and lines for damage". Refer to SAFETY PRECAUTIONS WHEN WORKING NEAR HIGH-VOLTAGE COMPONENTS and SAFETY PRECAUTIONS WHEN WORKING ON VEHICLES WITH HIGH-VOLTAGE SYSTEM .

If working on high-voltage system components is necessary, de-energize the high-voltage system. Refer to [For engine(s) DCBD] High-Voltage System, De-Energizing .

De-energizing the high-voltage system and re-energizing the high-voltage system. Refer to [For engine(s) DCBD] High-Voltage System, De-Energizing .

-- Charge the vehicle battery, for example, using the Battery Charger:VAS 5904 in the battery support mode to minimize the number of automatic starts during the test- and measuring procedures when the ready mode is active. Refer to BATTERY, CHARGING and SAFETY PRECAUTIONS WHEN WORKING ON THE HIGH-VOLTAGE SYSTEM .

-- Move the selector level into position "P", activate the parking brake and arrange the necessary tools for testing and measuring procedures that require the ready mode to be active or that require the ignition to be on, so that they cannot come into contact with the turning components of the engine and so that they cannot come into the vicinity of the turning components of a running engine by themselves.

Electrically-Driven A/C Compressor

Fig 1: Identifying E-A/C Compressor

Courtesy of AUDI OF AMERICA, LLC

CAUTION:

Risk of destroying the electrically-driven A/C compressor due to short circuit.

- Never touch the A/C compressor when the ignition is turned on or when the drive machines are activated.

The A/C compressor extracts the refrigerant gas from the evaporator, compresses it and sends it to the condenser.
The electric motor for the A/C compressor is supplied with voltage from the Electric Drive Power and Control Electronics -JX1-. Refer to Wiring Diagram.
The A/C Compressor Control Module -J842- integrated in the A/C compressor regulates the speed and thereby the A/C compressor output (Electrical A/C Compressor -V470-) according to request received via the data bus. Use the Vehicle Diagnostic Tester in the "Guided Fault Finding" function for the A/C System and the battery control.
There is no A/C Compressor Regulator Valve -N280- installed in the electrically-driven A/C compressor.
Check the attachment points on the A/C compressor and the bracket prior to installation. The contact services must be clean and free of rust and grease. Otherwise, service the contact surface using the Contact Surface Cleaning Set:VAS 6410 . Refer to Wiring Harnesses and Connectors, Repairing and Contact Surface Cleaning Set VAS6410 .

NOTE:

Check the amount of refrigerant oil in the new A/C compressor if the A/C Compressor Control Module -J842- is faulty. The refrigerant circuit does not always have to be cleaned (flushed) with R1234yf.

The A/C Compressor Control Module -J842- and the Electrical A/C Compressor -V470- are one component and are currently not able to be separated.

There is no A/C Compressor Regulator Valve A/C Compressor Regulator Valve -N280- installed in the electrically driven A/C compressor. The A/C compressor output is regulated externally by the A/C compressor speed. Refer to Wiring Diagram and Use the Vehicle Diagnostic Tester in the "Guided Fault Finding" function for the A/C system and the battery regulation.

The electrically-driven A/C compressor currently functions according to the principle of a spiral charger (similar to a G-charger).

The A/C compressor contains refrigerant oil, which can be mixed with refrigerant R1234yf at any temperature.

The type plate lists the type of refrigerant required for the A/C compressor.

The installed electronics regulate the A/C compressor power output (and the pressure on the low pressure side as a result) within the specified range (control characteristic) via the speed.

The engine should only be started if the refrigerant circuit is completely assembled.

The A/C compressor is supplied with a specific amount of oil that prevents the A/C compressor from becoming damaged when the refrigerant circuit is empty. This means that approximately 40 to 50 cm³ of refrigerant oil remains in the A/C compressor.

The electrically-driven A/C compressor has a pressure relief valve like the mechanically-driven A/C compressor.

Electric or hybrid drive on vehicles with battery cooling is only possible with a fully charged A/C system in which there are no stored errors. Refer to Vehicle Diagnostic Tester in the "Guided Fault Finding" function for the A/C system and the battery regulation.

After the installing the electrically-driven A/C compressor and the subsequent charging the refrigerant circuit, first start the A/C compressor using the "compressor cut-in" function of the basic setting. If refrigerant oil has accumulated in the A/C compressor compression chamber before installation due to improper storage, this could cause damage to the A/C compressor. Refer to Vehicle Diagnostic Tester in the "Guided Fault Finding" function for A/C System and Battery Regulation.

Only activate the electrically-driven A/C compressor when the refrigerant circuit is filled. The A/C compressor may become damaged if the A/C compressor is run while the refrigerant circuit is empty. Use the Vehicle Diagnostic Tester in the "Guided Fault Finding" function.