| Starting up air conditioner after charging refrigerant circuit |
| Vehicles with a high-voltage system (hybrid vehicles) |
| As work in the vicinity of high-voltage system components is necessary for the following sequence of operations, perform „Visual inspection of high-voltage components and cables for damage“ → Chapter and heed the „General warnings for working on high-voltage system“ → Electrical system; Rep. gr.93 |
WARNING | Danger from unexpected engine starting |
| When performing general work on vehicles with a high-voltage system, switch off the ignition and remove the ignition key from the passenger compartment. |
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WARNING | Working on vehicles with high-voltage wiring: |
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| Do not support yourself or tools on high-voltage wiring or associated components --> this can damage the insulation. |
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| High-voltage wiring must not be excessively bent or kinked --> this can damage the insulation. |
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| The round high-voltage connectors are colour-coded with an external coloured ring and are provided with mechanical coding or guide lugs. It is important to observe this coding when joining up the round high-voltage connectors, otherwise the connectors can be damaged. |
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DANGER! | Risk of fatal injury if high-voltage components are damaged. |
| Observe the following when working in the vicinity of high-voltage components or wiring: |
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| It is not permitted to use cutting or forming tools, other sharp-edged tools or heat sources such as welding, brazing, soldering, hot air or thermal bonding equipment. |
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| Before starting work, visually inspect the high-voltage components in the areas involved. |
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| Before working in the engine compartment, visually inspect the power electronics -JX1-, electric drive motor -V141-, air conditioner compressor -V470- and high-voltage wiring. |
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| Before working on the vehicle underbody, visually inspect the high-voltage wiring and covers. |
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| Before working on the rear section of the vehicle, visually inspect the high-voltage wiring and the electro-box with the maintenance connector for high-voltage system - TW -. |
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| Visually inspect all potential equalisation lines. |
| Check the following when making the visual inspection: |
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| There must be no external damage on any component. |
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| The insulation of the high-voltage wiring and potential equalisation lines must not be damaged. |
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| There must be no unusual deformation of the high-voltage wiring. |
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| All high-voltage components must be identified by a red warning sticker. |
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| After installing the air conditioner compressor and then filling the refrigerant circuit, first start up the electrically driven air conditioner compressor by way of the „Compressor run-in“ function of the basic setting routine. Otherwise, the air conditioner compressor may be damaged if refrigeration oil has accumulated in the compressor chamber of the air conditioner compressor on account of inappropriate storage prior to installation. → Vehicle diagnostic tester, „Guided fault-finding“ function for air conditioner and battery regulation |
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| All components removed re-installed. |
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| Switch on the ignition. |
Note | Vehicles with no high-voltage system |
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| Do not start the engine until the refrigerant circuit has been assembled. |
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| If possible only start the engine with the refrigerant circuit charged. |
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| The air conditioner compressor without air conditioning system magnetic clutch -N25- is always driven when the engine is running. On vehicles with an air conditioner compressor without -N25-, the engine is therefore only to be started with the refrigerant circuit properly assembled. If, for example, the refrigerant lines have not been connected to the air conditioner compressor, heat generation inside the air conditioner compressor with the engine running may lead to the destruction of the compressor. The internal heat generation is caused by the air conditioner compressor operating against a fixed resistance even at approximately 0 % delivery rate (sealed circuit). |
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| As of Model Year 2012, certain vehicles with a 4-cyl. engine are gradually to be fitted with an air conditioner compressor additionally provided with an air conditioning system magnetic clutch -N25- → Chapter. In certain air conditioner operating modes (e.g. „Econ“ mode), the air conditioner compressor drive system is completely deactivated by way of this magnetic clutch. For -N25- to be actuated by the operating and display unit, Climatronic control unit -J255-, the correct version of -J255- must be fitted and correctly encoded → Electronic parts catalogue and → Vehicle diagnostic, testing and information systemVAS 5051/, ”Guided fault-finding” function. |
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| The air conditioner compressor without -N25- is always driven by the pulley or the drive shaft. In no-load operation, air conditioner compressor lubrication is maintained by way of an „internal oil circuit“ to prevent damage. |
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| The air conditioner compressor is equipped with an „internal oil circuit“ to prevent damage if the refrigerant circuit is empty. A prerequisite for this internal lubrication is that there is still a residual quantity of refrigeration oil in the air conditioner compressor. |
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| The engine is not to be started unless the refrigerant circuit has been properly assembled. If, for example, the refrigerant lines have not been connected to the air conditioner compressor, heat generation inside the air conditioner compressor with the engine running may lead to the destruction of the compressor. |
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| The air conditioner compressor regulating valve -N280- is not actuated if the refrigerant circuit is empty and the air conditioner compressor runs at idle with the engine. However, as there is no refrigerant available, the refrigeration oil required for air conditioner compressor lubrication is not conveyed. |
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| All components removed re-installed. |
| If it is necessary to start the engine with an empty refrigerant circuit: |
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| The refrigerant circuit must have been completely assembled. |
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| There must not be any vacuum in the refrigerant circuit. |
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| There must be at least a quarter of the quantity of refrigeration oil specified for this refrigerant circuit in the air conditioner compressor. |
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| The engine speed must not exceed 2500 rpm. |
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| The engine should only run as long as is absolutely necessary. |
| Heed the following on starting the engine for the first time after charging the refrigerant circuit: |
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| Switch on the ignition. |
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| Start the engine with the air conditioner compressor switched off („Econ“ mode set, lamp in AC button not lit) and wait for the engine idling speed to stabilise. |
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| Open all dash panel vents. |
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| Set the air conditioner operating and display unit, Climatronic control unit -J255- to the „Cold“ temperature setting (for the driver and front passenger side). |
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| Switch on the air conditioner compressor by pressing the AC button („Auto“ mode selected and lamp in AC button lights) and allow the air conditioner compressor to run for at least 5 minutes with the engine idling. |
Note |
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