Electrically-Driven A/C Compressor
Vehicles with a High-Voltage System (Hybrid Vehicles)
If procedures are necessary near the components of the high-voltage system. Refer to SAFETY PRECAUTIONS WHEN WORKING NEAR HIGH-VOLTAGE COMPONENTS in "Performing a visual inspection of the high-voltage components and cables" and the appropriate service information .
If working on high-voltage system components is necessary, de-energize the high-voltage system. Refer to the appropriate service information .
De-energizing the high-voltage system and re-energizing the high-voltage system. Refer to the appropriate service information .
-- Charge the vehicle battery, for example, using the Battery Charger :VAS5904 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 the appropriate service information .
-- 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 are not in the vicinity of the turning components of a running engine.
Electrically-Driven A/C Compressor
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 relays 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 the appropriate 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 surfaces must be clean and free of rust and grease. Otherwise service the contact surface using the Contact Surface Cleaning Set :VAS6410 . Refer to WIRING HARNESS AND CONNECTOR REPAIRS and Contact Surface Cleaning Set VAS6410 .
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 -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 the appropriate 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 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 are controlled by the speed of the A/C compressor power output (and the pressure on the low pressure side) within the specified range (control characteristic).
The engine should only be started if the refrigerant circuit is completely assembled.
The A/C compressor is equipped with a protected oil supply, this prevents A/C compressor damage in the event that the system 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 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 installation of the electrically-driven A/C compressor and the subsequent filling of the refrigerant circuit, start the A/C compressor for the first time using the "compressor intake" function for the basic setting. The A/C compressor may otherwise become damaged if refrigerant oil was improperly stored in the A/C compressor compression chamber before installation. Use the Vehicle Diagnostic Tester in the"Guided Fault Finding" Function for A/C System and Battery Regulator.
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.