A/C System, Starting Operation After Filling Refrigerant Circuit
On 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. Refer to HIGH VOLTAGE VEHICLES SAFETY PRECAUTIONS and HIGH VOLTAGE SYSTEM GENERAL WARNINGS .
If it is necessary for the following procedure to perform work near high voltage components, "perform a visual inspection of the high voltage components and cables for damages" (refer to PERFORMING A VISUAL INSPECTION OF DAMAGE TO HIGH VOLTAGE COMPONENTS AND CABLES ) and "always follow the warnings when working on the high voltage system". Refer to HIGH VOLTAGE SYSTEM GENERAL WARNINGS .
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.
- 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 before installation, refrigerant oil was improperly stored in the A/C compressor compression chamber using the Vehicle Diagnostic Tester in the "Guided Fault Finding " function
- Only activate the electrically driven A/C compressor when the refrigerant circuits are filled. Damage to the A/C compressor may occur if the A/C compressor is running while the refrigerant circuit is empty using the Vehicle Diagnostic Tester in the "Guided Fault Finding " function
- All removed parts are installed once again.
- The refrigerant circuit is filled. Refer to USING SERVICE STATION . For additional information, refer to OVERVIEW - REFRIGERANT CIRCUIT, NOT OPENING THE REFRIGERANT CIRCUIT, VEHICLES WITHOUT HIGH VOLTAGE SYSTEM and OVERVIEW - REFRIGERANT CIRCUIT, OPENING THE REFRIGERANT CIRCUIT, VEHICLES WITHOUT HIGH VOLTAGE SYSTEM (Refrigerant R134a, Servicing; Refrigerant Circuit, Using Service Station).
-- Turn on the ignition.
-- Check the DTC memory for the Climatronic Control Module -- display and control head and erase any displayed malfunctions, if necessary using the Vehicle Diagnostic Tester in the "Guided Fault Finding " function.
-- Operate the Electrical A/C Compressor -V470- via the "compressor cut-in" function using the Vehicle Diagnostic Tester in the "Guided Fault Finding " function.
Observe the information regarding operating the A/C system after filling. Refer to A/C SYSTEM, OPERATING AFTER CHARGING , (Refrigerant R134a, Servicing; A/C System, General Information). After charging the A/C system before activating the A/C system.
For 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 A/C SYSTEM, STARTING OPERATION AFTER FILLING REFRIGERANT CIRCUIT (Refrigerant R134a, Servicing; A/C System, General Information).
The A/C compressor without an A/C Clutch -N25- is always driven when the engine is running. If the vehicle has an A/C compressor without an A/C Clutch -N25-, 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 A/C compressor is confronted with a fixed resistance (sealed circuit).
An A/C compressor with an A/C Clutch -N25- is installed as a running change on certain 4-Cylinder vehicles from MY 2012. Refer to BELT PULLEY, REMOVING AND INSTALLING, A/C COMPRESSOR WITH A/C Clutch -N25- . The A/C clutch turns off the A/C compressor drive completely under certain conditions (for example "ECON"). The correct Climatronic Control Module -J255- version must be installed and coded correctly so that the A/C Clutch -N25- can be activated by the Climatronic Control Module - J255- display and control head. Using the Vehicle Diagnostic Tester in the "Guided Fault Finding " function.
The A/C compressor without A/C clutch -N25- is always driven by the belt pulley or input shaft. 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. Prerequisite for the internal lubrication is residual refrigerant oil in A/C compressor.
The engine may start 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.
- All removed parts are installed once again.
- The refrigerant circuit is filled. Refer to USING SERVICE STATION . For additional information, refer to OVERVIEW - REFRIGERANT CIRCUIT, NOT OPENING THE REFRIGERANT CIRCUIT, VEHICLES WITHOUT HIGH VOLTAGE SYSTEM and OVERVIEW - REFRIGERANT CIRCUIT, OPENING THE REFRIGERANT CIRCUIT, VEHICLES WITHOUT HIGH VOLTAGE SYSTEM (Refrigerant R134a, Servicing; Refrigerant Circuit, Using Service Station).
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.
-- Check the DTC memory for the Climatronic Control Module -- display and control head and erase any displayed malfunctions, if necessary using the Vehicle Diagnostic Tester in the "Guided Fault Finding " function.
-- Start the engine with the A/C compressor switched off ("Econ" mode set, indicator lamp in AC or A/C button does not light up), and wait until engine idle speed has stabilized.
-- Open all instrument panel vents.
-- Set the temperature preset on the Climatronic Control Module -J255- A/C display and control head to "cold" (for the driver and front passenger side).
-- Press the AC or A/C button to switch on the A/C compressor ("Auto" mode selected and the indicator lamp in the AC or A/C button lights up) and let the A/C compressor idle with the engine for at least five minutes.
Observe the information regarding operating the A/C system after filling. Refer to A/C SYSTEM, OPERATING AFTER CHARGING , (Refrigerant R134a, Servicing; A/C System, General Information). After charging the A/C system before activating the A/C system.