Notes On 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 .
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 damages and follow the "warnings when working on the high voltage system". Refer to PERFORMING A VISUAL INSPECTION OF DAMAGE TO HIGH VOLTAGE COMPONENTS AND CABLES .
If it is necessary to perform work on the high voltage system components, de-energize the high voltage system. Refer to appropriate service information and read and follow the "high voltage electrical system general warnings" .
The A/C Compressor Control Module -J842- Integrated In The Electrically-Driven A/C Compressor Regulates The Blower Speed And Therefore The A/C Compressor Output (Electrical A/C Compressor -V470-).
For Vehicles Without A High Voltage System
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. Refer to use the Vehicle Diagnostic Tester in the "Guided Fault Finding " function.
To stop the A/C compressor being destroyed when the refrigerant circuit is empty, it is designed such that delivery is reduced to roughly 0% and lubrication is maintained by way of an internal oil circuit with the oil left in the A/C compressor.
ALL VEHICLES
No Refrigerant May Be Added To The Refrigerant Circuit (Discharge, Evacuate And Fill The Circuit). Refer to TECHNICAL DATA , (Refrigerant R134a Servicing, Refrigerant Circuit, Working with A/C Service Station) or
The entire amount of refrigerant oil to be added to the refrigerant circuit is located in the replacement compressor. Refer to TECHNICAL DATA , REFRIGERANT R134A CAPACITIES, REFRIGERANT OIL AND APPROVED REFRIGERANT OILS or REFRIGERANT CIRCUIT -R1234yf .
Different refrigerant oils are required for A/C compressors made by Denso, Sanden and Zexel/Valeo. Refer to REFRIGERANT R134A CAPACITIES, REFRIGERANT OIL AND APPROVED REFRIGERANT OILS (Refrigerant R134a Servicing; Refrigerant R134a Capacities, Refrigerant Oil and Approved Refrigerant Oil), A/C SYSTEM, GENERAL INFORMATION .
Coat the O-ring seals lightly with refrigerant oil prior to installation. Refer to REFRIGERANT CIRCUIT SEALS .
The specified diameters for O-rings and the tightening specification pertain also to the threaded connections of the refrigerant lines or refrigerant hoses between the separate components.
Only install O-rings that are approved for refrigerant R134a. Refer to REFRIGERANT CIRCUIT SEALS , A/C SYSTEM, GENERAL INFORMATION or REFRIGERANT CIRCUIT .
Check the cooling output. Refer to COOLING OUTPUT, CHECKING .
Check the pressures in the refrigerant circuit. Refer to REFRIGERANT CIRCUIT (Refrigerant R134a Servicing, Refrigerant Circuit, Working with A/C Service Station) or A/C SYSTEM, GENERAL INFORMATION .
All other maintenance and testing procedures on the refrigerant circuit not described in this service information. Refer to A/C SYSTEM, GENERAL INFORMATION or REFRIGERANT CIRCUIT - R1234yf .
Operate the A/C system after charging the refrigerant circuit. Refer to A/C SYSTEM, STARTING OPERATION AFTER FILLING REFRIGERANT CIRCUIT .
From the start of production up to the change-over from MY 2012, evaporators approximately 40 mm wide (block depth) were installed (A/C unit part number "8K_ 820 005"). From MY 2012 as a running change, an evaporator with an approximately 50 mm width (block depth) is being installed depending on the vehicle version (A/C unit part number "8T_ 820 005"). Pay attention to the correct allocation of the expansion valve to the evaporator (there are different versions).