A/C System Operating After Filling Refrigerant Circuit

A/C System Operating After Filling Refrigerant Circuit

• 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).

• 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 residual refrigerant oil in the A/C compressor and 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. As there is no refrigerant in the circuit the oil required to lubricate is not fed to the A/C compressor.

• All removed parts are installed once again.

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 1/4 of the prescribed refrigerant oil must be in the A/C compressor.

• No not rev engine higher than 2500 rpm.

• The engine should only run as long as is absolutely necessary.

Note The Following When Starting Engine For First Time After Filling Refrigerant Circuit:

- Switch on the ignition

- Set OFF on the Climatronic control module (J255) (and also the rear A/C display control head (E265) if present). The indicator lamps in the OFF button of the Climatronic control module (and of the rear A/C display control head 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 5 minutes (with the A/C compressor off).

- Open all instrument panel vents and the vents in the center console and in the B-pillars.

- Activate the A/C system and the activation of the A/C compressor by pressing the AUTO button on the Climatronic control module (select the Auto mode and the indicator lamps in the AUTO buttons and the AC button of the Climatronic control module illuminate).

- Press the SYNC button on the Climatronic control module.

• 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 if present.

• If the indicator lamp in the AC button of the Climatronic control module does not illuminate, press the AC button of the Climatronic control module.

- Check the indicator lamps in the AUTO buttons on the rear A/C display control head (if present). If they do not illuminate, press the AUTO buttons of the rear A/C display control head.

- Set the temperature preselection for the driver side on the Climatronic control module to cold.

• By previously 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 if present.

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- Check the temperature preselection for the front passenger side on the v (and also on the rear A/C display control head if present) and set it to cold if necessary.

- Allow the engine to idle for at least 5 minutes with the A/C compressor switched on.

• After the A/C compressor is started as described, the cooling output of the A/C system can now be checked if necessary, refer to => [ A/C Unit, Checking Cooling Output ] A/C Unit, Checking Cooling Output.