A/C System, Operating After Filling Refrigerant Circuit

A/C System, Operating After Filling Refrigerant Circuit

• Start engine only 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 belt pulley (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.

• The refrigerant circuit is filled.

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






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

• The indicator lamp in the AC button - 9 - does not illuminate.

- Open all instrument panel vents, the vents in the center console and the vents in the B-pillar if present.

- Switch the A/C compressor on by selecting the "Auto" mode on the Climatronic control module (J255) (and on the Rear A/C display control head (E265) if present) (the indicator lamps in the AUTO buttons and the AC button illuminate).

• The indicator lamp in the buttons - 2, 4, 9 - illuminates.

• The indicator lamp in the buttons - 3, 6 - illuminates.






• By pressing the SYNC button - 10 - on the Climatronic control module (only in the comfort version), the settings for the front driver side are applied to the front passenger side and also on the Rear A/C display control head.






- Via the rotary switches of the Climatronic control module, the temperature preselection is set to cold (for the driver and front passenger side).

- In vehicles with a Rear A/C display control head, also set the temperature preselection for the rear to cold (for the left and right side).

• 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.

- Allow the A/C compressor to idle for at least 5 minutes.

• Note the information regarding operating the A/C system after filling.