Pre-Entry Climate Control, Function - GF83.40-P-2014FG

Model 213.016/050/053/054/216 

up to model year 2021 

Courtesy of MERCEDES-BENZ USA

Shown on model 213 as of 01.06.2018 

Courtesy of MERCEDES-BENZ USA

Shown on model 213 up to 31.05.2018 

Function requirements, general 

• No overvoltage or undervoltage of the high-voltage battery
• Charge level of the high-voltage battery over the minimum charge level
• Pre-entry climate control pre-configured with menu in the head unit
• Circuit 15C OFF

The electronic ignition lock control unit sends the status of terminal 15 via interior CAN to the A/C control unit.

The head unit sends the information regarding the pre-entry climate control settings via the user interface CAN, electronic ignition lock control unit and interior CAN to the climate control control unit.

Pre-entry climate control in general 

The vehicle interior of the parked vehicle can be preheated or pre-cooled as needed before starting to drive and the air quality improved (with code P21 (Air quality package)).

The pre-entry climate control can be switched on as follows:

• Immediately:
  • By unlocking when getting into the vehicle
  • By pressing the pre-entry climate control button
• Preprogrammed by activation of the departure time
  • Via the menu structure of the head unit
  • Web-based via a browser, e.g. using a smartphone, tablet or PC (with code 360 (HERMES UMTS) or code 362 (HERMES LTE))

Vehicles with code 360 (HERMES UMTS) or code 362 (HERMES LTE) 

If pre-entry climate control is programmed using a smartphone, tablet or PC, all data that describes the operating condition of the pre-entry climate control function is displayed there.

For this purpose, the climate control control unit continuously sends relevant information via the interior CAN, electronic ignition lock control unit and diagnostic CAN to the HERMES control unit, which stores the information. If requested, the HERMES control unit sends this information via emergency call system antenna 1 or emergency call system antenna 2 (with code 362 (HERMES LTE)) for display on the smartphone, tablet or PC.

The pre-entry climate control encompasses the following subfunctions:

• Pre-entry climate control when unlocking central locking (CL) 
• Pre-air conditioning for departure time 
• Pre-entry climate control via pre-entry climate control button 
• Air quality improvement (with code P21 (Air quality package)) 

Pre-entry climate control when unlocking CL 

When the CL is unlocked, pre-entry climate control is requested in order to cool or heat the driver area depending on the interior temperature.

The transmitter key sends its access authorization code via the rear window antenna and the FM, AM, CL, DAB and KEYLESS-GO antenna amplifier to the KEYLESS-GO control unit. The KEYLESS-GO control unit sends this signal to the electronic ignition lock control unit via interior CAN.

The electronic ignition lock control unit checks the access authorization code. If the code is valid, the electronic ignition lock control unit sends the request to start the pre-entry climate control to the climate control control unit via interior CAN. The A/C control unit then starts the pre-entry climate control.

The driver area is cooled or heated depending on the interior temperature.

The interior temperature in the head area is recorded by the interior temperature sensor with the integrated fan that is incorporated into the overhead control panel control unit. The integrated fan of the interior temperature sensor draws the air for temperature measurement out of the vehicle interior. The overhead control panel control unit reads in the value of the interior temperature and transmits this via the interior CAN to the climate control control unit. The climate control control unit compares this value with the settings at the climate control operating unit. The climate control operating unit sends the control signals via climate control LIN to the climate control control unit.

If the interior temperature is at least 4°C above the set specified temperature, the vehicle is cooled. If the interior temperature is at least 4°C below the set specified temperature, the vehicle is heated. If the lowest possible specified temperature "Lo" is set on the climate control operating unit, the vehicle is always cooled. If the highest possible specified temperature "Hi" is set on the climate control operating unit, the vehicle is always heated.

To cool the driver area, the climate control control unit activates the following functions:

• Automatic air conditioning:

  The climate control control unit actuates the electric refrigerant compressor via climate control LIN 2 and sends the request to switch on the blower motor via climate control LIN 2 to the electronic blower motor.

• Seat ventilation (with code 401 (Seat climate control for driver and front passenger)):

  The climate control control unit sends the request to switch on the seat ventilation via the interior CAN to the rear SAM control unit, which forwards the request depending on the vehicle equipment.

  The seat ventilation remains switched on even after engine start.

The driver area is cooled for max. 300 s. Cooling mode is ended after this time or when the engine is started.

To heat the driver area, the climate control control unit activates the following functions:

• Automatic air conditioning:

  The climate control control unit actuates the electric refrigerant compressor via climate control LIN 2 and sends the request to switch on the blower motor via climate control LIN 2 to the electronic blower motor.

  The electric refrigerant compressor is activated to dry the air flowing out and thus prevent fogging of windows.

• Seat heating (with code 401 (Seat climate control for driver and front passenger) or code 873 (Seat heating for driver and front passenger) (outside temperature below 10°C)):

  The climate control control unit sends the request to switch on the seat heater via the interior CAN to the rear SAM control unit, which forwards the request depending on the vehicle equipment.

  The seat heater remains switched on even after engine start.

• Steering wheel heater (with code 443 (Steering wheel heater)):

  The climate control control unit transmits the request to switch on the steering wheel heater to the steering wheel electronics via the interior CAN, electronic ignition lock control unit, suspension FlexRay, steering column tube module control unit and steering wheel CAN (as of 01.06.2018) or steering LIN (up to 31.05.2018).

• Heated windshield (with code 597 (Windshield, heated)) (outside temperature below 10°C):

  The climate control control unit sends the target value for heat output to the windshield heater control unit via climate control LIN 2. The windshield heater control unit accordingly actuates the heated windshield.

• Rear window heater (outside temperature below 5°C): The A/C control unit sends the request to switch on the rear window heater via interior CAN to the rear SAM control unit.
• Mirror heater (dew point temperature 2°C below outside temperature):

  The A/C control unit sends the request to switch on the mirror heater via interior CAN to the left front door control unit and to the right front door control unit.

The mirror heater remains switched on even after engine start.

The driver area is heated for a max. of 300 s. Heating mode is ended after this time or when the engine is started.

If the on-board electrical system is stable, pre-entry climate control can be activated twice in succession (without the engine having to be started).

Pre-air conditioning for departure time 

The departure time can be programmed through the head unit or web-based via a browser, e.g. using a smartphone, tablet or PC (with code 360 (HERMES UMTS) or code 362 (HERMES LTE)). Up to three departure times can be configured. The vehicle interior is cooled or heated before departure.

Programming departure time using heat unit: 

The head unit sends information regarding the pre-entry climate control settings via the user interface CAN, electronic ignition lock control unit and interior CAN to the climate control control unit. The climate control control unit then calculates the time required for pre-entry climate control and sends this via the interior CAN, electronic ignition lock control unit and chassis FlexRay to the powertrain control unit. The powertrain control unit then calculates the starting time for pre-entry climate control. When the starting time is reached, the powertrain control unit sends the pre-entry climate control request via the chassis FlexRay, electronic ignition lock control unit and interior CAN to the climate control control unit.

Web-based programming of departure time, e.g. using a smartphone, tablet or PC (with code 360 (HERMES UMTS) or code 362 (HERMES  LIE)).

The HERMES control unit receives the information regarding the pre-entry climate control settings via emergency call system antenna 1 or emergency call system antenna 2 (with code 362 (HERMES LTE)) and sends this information via the diagnostic CAN, the electronic ignition lock control unit and the interior CAN to the climate control control unit. The climate control control unit then calculates the time required for pre-entry climate control and sends this via the interior CAN, electronic ignition lock control unit and chassis FlexRay to the powertrain control unit. The powertrain control unit then calculates the starting time for pre-entry climate control. When the starting time is reached, the powertrain control unit sends the pre-entry climate control request via the chassis FlexRay, electronic ignition lock control unit and interior CAN to the climate control control unit.

When a departure time has been activated, the LED in the pre-entry climate control button lights up yellow. The powertrain control unit sends the request to switch on the LED via the chassis FlexRay, electronic ignition lock control unit, interior CAN, climate control control unit and climate control LIN to the climate control operating unit. The climate control operating unit actuates the LED in the pre-entry climate control button.

To operate pre-entry climate control, the climate control control unit assesses the following factors:

• Interior temperature in head area:

  The interior temperature in the head area is recorded by the interior temperature sensor with the integrated fan that is incorporated into the overhead control panel control unit. The integrated fan of the interior temperature sensor draws the air for temperature measurement out of the vehicle interior. The overhead control panel control unit reads in the value of the interior temperature and transmits this via the interior CAN to the climate control control unit.

• Specified temperature at the climate control operating unit: The climate control operating unit sends the control signals via climate control LIN to the climate control control unit.
• Outside temperature:

  The outside temperature sensor measures the outside temperature. The front SAM control unit reads in the signal from the outside temperature sensor, calculates the outside temperature and sends it to the climate control control unit via the interior CAN.

• Solar radiation:

  The sun sensor in the rain/light sensor with additional function detects the angle of incidence and the intensity of the solar radiation entering the vehicle. The rain/light sensor with additional functions sends corresponding information via the rain/light sensor LIN, front SAM control unit and interior CAN to the climate control control unit.

  For example, in the event of one-sided solar radiation, an appropriate temperature difference is set between the left and the right specified control temperatures.

If the interior temperature is at least 4°C above the set specified temperature, the vehicle is cooled. If the interior temperature is at least 4°C below the set specified temperature, the vehicle is heated. If the lowest possible specified temperature "Lo" is set on the climate control operating unit, the vehicle is always cooled. If the highest possible specified temperature "Hi" is set on the climate control operating unit, the vehicle is always heated.

To cool the vehicle interior, the climate control control unit activates the following functions:

• Automatic air conditioning:

  The climate control control unit actuates the electric refrigerant compressor via climate control LIN 2 and sends the request to switch on the blower motor via climate control LIN 2 to the electronic blower motor.

• Seat ventilation (with code 401 (Seat climate control for driver and front passenger)):

  The climate control control unit sends the request to switch on the seat ventilation via the interior CAN to the rear SAM control unit, which forwards the request depending on the vehicle equipment.

  The seat ventilation remains switched on even after engine start.

  To heat the vehicle interior, the climate control control unit activates the following functions:

• Automatic air conditioning:

  The climate control control unit actuates the high voltage PTC heater over the climate control LIN 2. The high voltage PTC heater heats up the coolant. The coolant temperature in the high voltage PTC heater is recorded by the temperature sensor for the high voltage PTC heater. The high-voltage PTC heater sends the coolant temperature via climate control LIN 2 to the climate control control unit. When the coolant has reached a temperature of 35°C, the climate control control unit actuates the coolant circulation pump and sends the request to switch on the high-voltage PTC heater switchover valve via climate control LIN 2 to the high-voltage PTC heater and the request to switch on the blower motor via climate control LIN 2 to the electronic blower motor. The high-voltage PTC heater switchover valve regulates the flow of coolant (small or large coolant circuit). The climate control control unit actuates the electric refrigerant compressor via climate control LIN 2 in order to ensure that the air flowing out is dried, thus preventing fogging of the windows.

  • Seat heating (with code 401 (Seat climate control for driver and front passenger) or code 873 (Seat heating for driver and front passenger) (outside temperature below 10°C)):

    The climate control control unit sends the request to switch on the seat heater via the interior CAN to the rear SAM control unit, which forwards the request depending on the vehicle equipment.

    The seat heater remains switched on even after engine start.

  • Steering wheel heater (with code 443 (Steering wheel heater)): The climate control control unit transmits the request to switch on the steering wheel heater to the steering wheel electronics via the interior CAN, electronic ignition lock control unit, suspension FlexRay, steering column tube module control unit and steering wheel CAN (as of 01.06.2018) or steering LIN (up to 31.05.2018).
  • Heated windshield (with code 597 (Windshield, heated)) (outside temperature below 10°C):

    The climate control control unit sends the target value for heat output to the windshield heater control unit via climate control LIN 2.

  • Rear window heater (outside temperature below 5°C): The A/C control unit sends the request to switch on the rear window heater via interior CAN to the rear SAM control unit.
  • Mirror heater (dew point temperature 2°C below outside temperature):

    The A/C control unit sends the request to switch on the mirror heater via interior CAN to the left front door control unit and to the right front door control unit.

The mirror heater remains switched on even after engine start.

The steering wheel heater and the mirror heater are actuated for max. 10 min and the seat heater and the rear window heater for max. 15 min before the departure time is reached.

The vehicle interior is cooled or heated until the desired temperature in relation to the set departure time has been reached. For this purpose, pre-entry climate control is activated max. 50 min in advance. If the departure is delayed, the vehicle interior is air-conditioned for an additional 5 min.

If the vehicle is connected to a power supply, the charging of the high-voltage battery to the specified minimum charge level has priority. The pre-entry climate control at the departure time is only activated following this.

If the vehicle is not connected to a power supply and the high-voltage battery is not completely charged, the operating time of the pre-entry climate control may be shortened.

Pre-entry climate control is ended when the vehicle is started or if 5 min have passed since the selected departure time expired.

Pre-entry climate control via pre-entry climate control button 

The pre-entry climate control can also be switched on if the desired interior temperature has already been reached. This allows the vehicle interior to be further air-conditioned and the interior temperature to be maintained at a constant level (e.g. also during an interruption in travel) for up to 50 min.

The pre-entry climate control is switched on and off by pressing the pre-entry climate control button in the climate control operating unit.

The climate control operating unit sends the status of the pre-entry climate control button via the climate control LIN to the climate control control unit.

The LED in the pre-entry climate control button shows the operating state of pre-entry climate control:

• Red: Heating is switched on.
• Blue: Cooling is switched on.
• Yellow: Departure time is preselected.
• Outside temperature:

  The outside temperature sensor measures the outside temperature. The front SAM control unit reads in the signal from the outside temperature sensor, calculates the outside temperature and sends it to the climate control control unit via the interior CAN.

To cool the vehicle interior, the climate control control unit activates the following functions:

• Automatic air conditioning:

  The climate control control unit actuates the electric refrigerant compressor via climate control LIN 2 and sends the request to switch on the blower motor via climate control LIN 2 to the electronic blower motor.

• Seat ventilation (with code 401 (Seat climate control for driver and front passenger)):

  The climate control control unit sends the request to switch on the seat ventilation via the interior CAN to the rear SAM control unit, which forwards the request depending on the vehicle equipment.

  The seat ventilation remains switched on even after engine start.

To heat the vehicle interior, the climate control control unit activates the following functions:

• Automatic air conditioning:

  The climate control control unit actuates the high voltage PTC heater over the climate control LIN 2. The high voltage PTC heater heats up the coolant. The coolant temperature in the high voltage PTC heater is recorded by the temperature sensor for the high voltage PTC heater. The high-voltage PTC heater sends the coolant temperature via climate control LIN 2 to the climate control control unit. When the coolant has reached a temperature of 35°C, the climate control control unit actuates the coolant circulation pump and sends the request to switch on the high-voltage PTC heater switchover valve via climate control LIN 2 to the high-voltage PTC heater and the request to switch on the blower motor via climate control LIN 2 to the electronic blower motor. The high-voltage PTC heater switchover valve regulates the flow of coolant (small or large coolant circuit). The climate control control unit actuates the electric refrigerant compressor via climate control LIN 2 in order to ensure that the air flowing out is dried, thus preventing fogging of the windows.

• Seat heating (with code 401 (Seat climate control for driver and front passenger) or code 873 (Seat heating for driver and front passenger) (outside temperature below 10°C)):

  The climate control control unit sends the request to switch on the seat heater via the interior CAN to the rear SAM control unit, which forwards the request depending on the vehicle equipment.

  The seat heater remains switched on even after engine start.

• Steering wheel heater (with code 443 (Steering wheel heater)):

  The climate control control unit transmits the request to switch on the steering wheel heater to the steering wheel electronics via the interior CAN, electronic ignition lock control unit, suspension FlexRay, steering column tube module control unit and steering wheel CAN (as of 01.06.2018) or steering LIN (up to 31.05.2018).

• Heated windshield (with code 597 (Windshield, heated)) (outside temperature below 10°C):

  The climate control control unit sends the target value for heat output to the windshield heater control unit via climate control LIN 2.

• Rear window heater (outside temperature below 5°C): The A/C control unit sends the request to switch on the rear window heater via interior CAN to the rear SAM control unit.
• Mirror heater (dew point temperature 2°C below outside temperature):

  The A/C control unit sends the request to switch on the mirror heater via interior CAN to the left front door control unit and to the right front door control unit.

  The mirror heater remains switched on even after engine start.

The powertrain control unit sends the request to switch on the indicator lamp via the chassis FlexRay, electronic ignition lock control unit, interior CAN, climate control control unit and climate control LIN to the climate control operating unit. The climate control operating unit actuates the LED in the pre-entry climate control button.

To operate pre-entry climate control, the climate control control unit assesses the following factors:

• Interior temperature in head area:

  The interior temperature in the head area is recorded by the interior temperature sensor with the integrated fan that is incorporated into the overhead control panel control unit. The integrated fan of the interior temperature sensor draws the air for temperature measurement out of the vehicle interior. The overhead control panel control unit reads in the value of the interior temperature and transmits this via the interior CAN to the climate control control unit.

• Specified temperature at the climate control operating unit:

  The climate control operating unit sends the control signals via climate control LIN to the climate control control unit.

Air quality improvement (with code P21 (Air quality package)) 

To improve the air quality in the vehicle, the following additional functions are also activated when starting the pre-entry climate control, if they were previously enabled via the operation menu in the head unit:

• Ionization
• Fragrancing

  Both functions cannot be selected separately. Even if there is no cooling or heating due to the assessment of the ambient data, both functions are started and switched off after one minute.

Ionization and fragrancing remain switched on even after engine start.