Procedure For First Engine Start After Charging Refrigerant Circuit

• All removed parts are reinstalled.
• The refrigerant circuit is charged. Refer to A/C System, General Information , Working with A/C Service Station or Working with A/C Service Station .
• Read the information for starting the A/C system after charging. Refer to A/C System, General Information , Working with A/C Service Station or Working with A/C Service Station . After recharging, before activating the A/C system.

• If the mechanically driven A/C compressor was removed or replaced, rotate it approximately 10 times by hand before using it for the first time (during or after installing, for example before installing the belt) to prevent damage caused by liquid impact when first switched on (any refrigerant oil in the A/C compressor cylinder is forced out on rotation). Refer to A/C COMPRESSOR, REMOVING AND INSTALLING .

If the A/C compressor was replaced: 

-- Also perform the test plan for automatic compressor cut-in using the Vehicle Diagnostic Tester.

Procedure 

-- Connect the Vehicle Vehicle Diagnostic Tester.

-- Select Diagnostic  mode and start the diagnosis.

-- Select the Test plan  tab.

-- Press the Select custom test  button and select the following tree structure in order:

• Body
• Heating, Ventilation & Air Conditioning
• OBD-capable systems
• 08- A/C/Heater Electronics - E87
• 08- A/C/Heater Electronics - Functions
• 08 - Basic Setting
• → Basic setting 3, compressor cut-in

Continuation for All Vehicles: 

Note the following when starting engine for first time after filling refrigerant circuit:

-- Open all instrument panel vents.

-- Switch the ignition on.

-- Adjust the "OFF" mode on the Front A/C Display Control Head -E87- (and on a vehicle with a "High" A/C system on the Rear A/C Display Control Head -E265-) the indicator lamp in the A/C  and the A/C MAX  button of the Front A/C Display Control Head -E87- does not turn on. 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 and wait until the engine idling speed has stabilized.

Set the following on the Front A/C Display Control Head -E87- : 

• "Auto" mode - the indicator lamp in the AUTO  button turns on.
• A/C compressor is on - the indicator lamp in the A/C  button turns on.

-- If possible select on the Front A/C Display Control Head -E87- the SYNC  functions.

-- Check the indicator lamps in the AUTO  buttons on the Front A/C Display Control Head -E87- (and the Rear A/C Display Control Head -E265- if present). If they do not turn on, press the AUTO  buttons.

-- Set the temperature preset for the driver side (and front passenger side) on the Front A/C Display Control Head -E87- to "cold".

-- Check the temperature preset for the front passenger side on the Front A/C Display Control Head -E87- (and also on the Rear A/C Display Control Head -E265- if present) and set it to "cold" if necessary.

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