A/C System, Starting Operation After Filling Refrigerant Circuit
Vehicles With A High Voltage System (Hybrid Vehicles)
Read and follow all of the supplemental warnings for all work performed on vehicles with the high voltage system, refer to HIGH VOLTAGE VEHICLES SAFETY PRECAUTIONS .
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 HIGH VOLTAGE COMPONENTS AND CABLES, CHECKING FOR DAMAGE ). and "always follow the warnings when working on the high voltage system", refer to HIGH VOLTAGE VEHICLES SAFETY PRECAUTIONS .
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 Air Conditioning (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.
- After the installation of the electrically-powered Air Conditioning (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, refer to 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 circuits are filled. The A/C compressor may become damaged if the A/C compressor is run while the refrigerant circuit is empty, refer to Vehicle Diagnostic Tester in the "Guided Fault Finding" Function for A/C System and Battery Regulator.
- All removed parts are installed once again.
- The refrigerant circuit is filled, refer to REFRIGERANT CIRCUIT, CHARGING - R1234yf / REFRIGERANT CIRCUIT, CHARGING WITH A/C SERVICE STATION - R134A .
-- Turn on the ignition.
-- Check the event memory display and control unit, the Climatronic Control Module -J255-, and erase any displayed malfunctions see Vehicle Diagnostic Tester in the "Guided Fault Finding" function.
-- Operate the Electrical A/C Compressor -V470- using the function "Compressor Cut-In", refer to Vehicle Diagnostic Tester in the "Guided Fault Finding" function for the A/C system and battery control.
Note the information regarding operating the A/C system after filling, refer to A/C SYSTEM, STARTING OPERATION AFTER FILLING REFRIGERANT CIRCUIT / A/C SYSTEM, OPERATING AFTER CHARGING .
Vehicles Without A High Voltage System
Only start engine after refrigerant circuit has been assembled.
If possible start engine only with a filled refrigerant circuit.
Do not start the engine while evacuating the refrigerant circuit or when the circuit is already evacuated (the A/C compressor could be damaged), refer to REFRIGERANT CIRCUIT, EVACUATING - R1234yf / REFRIGERANT CIRCUIT, EVACUATING WITH A/C SERVICE STATION - R134A .
The A/C compressor is always driven by the pulley or by the driveshaft (there is no magnetic clutch). To prevent damage when the compressor is idling, it is lubricated by an "Internal oil circuit".
The compressor has an "Internal oil circuit" to ensure the A/C compressor is not damaged when refrigerant circuit is empty. The prerequisite for the internal lubrication is a residual amount of refrigerant oil in the A/C compressor and there is no vacuum in the refrigerant circuit.
The engine may only be started when the refrigerant circuit is installed correctly. 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.
A/C Compressor Regulator Valve -N280- is not activated when the refrigerant circuit is empty and the A/C compressor idles with the engine. Since there is no refrigerant in the circuit, the required refrigerant oil for lubricating the A/C compressor is not supplied.
Note the information regarding operating the A/C system after filling, refer to A/C SYSTEM, STARTING OPERATION AFTER FILLING REFRIGERANT CIRCUIT / A/C SYSTEM, OPERATING AFTER CHARGING .
- All removed parts are installed once again.
- The refrigerant circuit is filled REFRIGERANT CIRCUIT, CHARGING - R1234yf / / REFRIGERANT CIRCUIT, CHARGING WITH A/C SERVICE STATION - R134A .
If it is Necessary to Start the Engine with A Discharged Refrigerant Circuit:
- Refrigerant circuit must be fully assembled.
- There must be no vacuum in the refrigerant circuit.
- At least a quarter of the prescribed refrigerant oil must be in the A/C compressor.
- Do not let the engine RPM go above 2, 500.
- The engine should only run as long as is absolutely necessary.
Note The Following when Starting Engine for First Time after Filling Refrigerant Circuit:
-- Turn on the ignition.
-- Set the "OFF" mode on the Climatronic Control Module -J255- front A/C display control head (and also the Rear A/C Display Control Head -E265- if present). The indicator lamps in the OFF button for the Climatronic Control Module -J255- (and for the Rear A/C Display Control Head -E265- if present) illuminate. The A/C system and the activation of the A/C compressor are switched off by the A/C Compressor Regulator Valve -N280-.
-- Start the engine with the A/C compressor switched off ("OFF" mode set) and let the engine idle for at least five minutes (with the A/C compressor off).
-- Open all instrument panel vents and the vents in the center console and in the B-pillars.
-- Turn on the A/C system and the A/C compressor activation by pressing the AUTO button on the Climatronic Control Module -J255- ("Auto" mode selected and indicator lamps in the AUTO buttons and the AC or A/C button for the Climatronic Control Module -J255- illuminate).
-- Press the SYNC button on the Climatronic Control Module -J255-.
By pressing the SYNC button, the settings for the front driver side are applied to the front passenger side and also on the Rear A/C Display Control Head -E265-.
If the indicator lamps in the AC or A/C button for the Climatronic Control Module -J255- do not illuminate, press the AC or A/C button for the Climatronic Control Module -J255-.
-- Check the indicator lamps in the AUTO buttons on the Rear A/C Display Control Head -E265- (if present). If they do not illuminate, press the AUTO buttons for the Rear A/C Display Control Head -E265-.
-- Set the temperature preselection for the driver side on the Climatronic Control Module -J255- to "cold".
By pressing the SYNC button beforehand, the settings for the front driver side are applied to the front passenger side and also on the Rear A/C Display Control Head -E265-.
-- Check the temperature preselection for the front passenger side on the Climatronic Control Module -J255- (and also on the Rear A/C Display Control Head -E265- if present) and set it to "cold" if necessary.
-- Allow the engine to idle for at least five minutes with the Air Conditioning (A/C) compressor switched on.
After the Air Conditioning (A/C) compressor is started as described, the cooling output of the A/C system can now be checked if necessary, refer to VEHICLES WITHOUT A HIGH VOLTAGE SYSTEM, CHECKING .