Procedures

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 A/C 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 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.

• Do 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

- Start engine with the A/C compressor switched off ("Econ" operating mode set, indicator light in AC button does not light up), and wait until engine idle speed has stabilized.

- Open all instrument panel vents.

- Set the temperature preset on the A/C Control Head Climatronic Control Module (J255) to "cold" (for the driver and passenger side).

- Press the AC button to switch on the A/C compressor ("Auto" mode selected and the indicator light in the AC button is on) and let the engine and A/C compressor idle for at least 5 minutes.

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