P83.40-A020-79
A1 | Instrument cluster | N69/1 | Left front door control unit | |
A2/18 | FM 1, AM, CL [ZV] and KEYLESS GO antenna amplifier | N69/2 | Right front door control unit | |
A2/32 | Rear window antenna | N69/5 | KEYLESS-GO control unit (with CODE 889 (KEYLESS-GO ) or CODE 893 (KEYLESS-GO start function)) | |
A2/52 | Emergency call system antenna (model 205.013/047/053/054/147/213/247/253, model 253.311/354/911/954/99 with code 360 (HERMES UMTS) or code 362 (HERMES LTE), model 205.047 with code 348 (Emergency call/assist system)) | N70 | Overhead control panel control unit | |
A2/102 | Left telephone antenna (model 205.047 with code 348 (Emergency call/assist system)) | N70b1 | Interior temperature sensor with integrated fan | |
A2/103 | Right telephone antenna (model 205.047 with code 348 (Emergency call/assist system)) | N73 | Electronic ignition switch control unit | |
A2/109 | Telephone antenna splitter (model 205.047 with code 348 (Emergency call/assist system)) | N80 | Steering column module control unit | |
A2/125 | Communications module/stationary heater antenna splitter (with code B24 (Remote control for stationary heater) and code B57 (COM MODULE battery level)) | N112/1 | Telematics services communications module (with CODE B57 (Battery level COM MODULE)) | |
A2/129 | Communications module/stationary heater antenna (with code B57 (COM MODULE battery level)) | N112/9 | HERMES control unit (model 205.013/047/053/054/147/213/247/253, model 253.311/354/911/954/99 with code 360 (HERMES UMTS)) | |
A8/1 | Transmitter key | N123/4 | Emergency call system control unit (model 205.047 with code 348 (Emergency call/assist system)) | |
A9/5 | Electric refrigerant compressor (model 205.012/013/047/053/054/147/212/213/247/253, model 253.311/354/911/954/99) | N127 | Drivetrain control unit | |
A9/5m1 | Refrigerant compressor electric motor (model 205.012/013/047/053/054/147/212/213/247/253, model 253.311/354/911/954/99) | N135 | Steering wheel electronics | |
A9/5n1 | Refrigerant compressor control unit and power electronics (model 205.012/013/047/053/054/147/212/213/247/253, model 253.311/354/911/954/99) | Y16/5 | High-voltage PTC heater switchover valve (model 205.013/047/053/054/147/213/247/253, model 253.311/354/911/954/99) | |
A26/17 | Head unit | A | Vehicles except CODE 889 (KEYLESS-GO) and except CODE 893 (KEYLESS-GO start function) | |
A32m1 | Blower motor | B | Vehicles with code (889) KEYLESS-GO or code (893) KEYLESS-GO start function | |
A32n1 | Blower regulator | C | Model 205 up to model year 2019, model 253 up to model year 2020 | |
B14 | Outside temperature sensor | D | Model 205 as of model year 2019, model 253 as of model year 2020 | |
B38/2 | Rain/light sensor with additional functions | CAN B | Interior CAN | |
B38/2b5 | Sun sensor | CAN D | Diagnostic CAN | |
M91/6 | Heating circuit circulation pump (model 205.013/047/053/054/147/213/247/253, model 253.311/354/911/954/99) | CAN HMI | User interface CAN | |
N10/6 | Front SAM control unit | CAN LR | Steering wheel CAN | |
N10/8 | Rear SAM control unit | Flex E | Chassis FlexRay | |
N22/1 | Climate control control unit | LIN B8-2 | Climate control LIN 2 | |
N33/5 | High-voltage PTC heater (model 205.013/047/053/054/147/213/247/253, model 253.311/354/911/954/99) | LIN B8-3 | AC operation LIN | |
N33/5b1 | High-voltage PTC heater temperature sensor (model 205.013/047/053/054/147/213/247/253, model 253.311/354/911/954/99) | LIN B16 | Rain and light sensor LIN | |
N58/1 | Climate control operating unit | LIN E1 | Steering LIN | |
N58/1s23 | Auxiliary climate control button (model 205.013/047/053/054/147/213/247/253, model 253.311/354/911/954/99) |
Function requirements, general
No overvoltage or undervoltage of high-voltage battery (model 205.012/013/047/053/054/147/212/213/247/253, model 253.311/354/911/954/99)
Charge level of high-voltage battery above minimum charge level (model 205.012/013/047/053/054/147/212/213/247/253, model 253.311/354/911/954/99)
Circuit 15C off:
The electronic ignition lock control unit sends the status of terminal 15 via interior CAN to the A/C 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 via remote activation (auxiliary climate control button on transmitter key) (model 205 with code 577 (Remote activation of heating and ventilation systems)), when entering by unlocking the vehicle (model 205.012/013/047/053/054/147/212/213/247/253, model 253.311/354/911/954/99) or by pressing the auxiliary climate control button (model 205.013/047/053/054/147/213/247/253, model 253.311/354/911/954/99)
Preprogrammed by activating a departure time in the instrument cluster (model 205.013/047/053/054/147/213/247/253, model 253.311/354/911/954/99) or web-based via a browser, e.g. using a smartphone, tablet or PC (model 205.013/047/053/054/147/213/247/253, model 253.311/354/911/954/99)
On model 205.013/047/053/054/147/213/247/253, model 253.311/354/911/954/99, the auxiliary climate control can be operated e.g. using a smartphone, a tablet or a PC via a browser. The current operating condition of the pre-entry climate control is shown there.
For this purpose, the climate control control unit continuously transmits information on the operating status of the auxiliary climate control via the interior CAN, electronic ignition lock control unit and diagnostics CAN to:
Telematics services communications module (with CODE B57 (Battery level COM MODULE))
HERMES control unit (model 205.013/047/053/054/147/213/247/253, model 253.311/354/911/954/99 with code 360 (HERMES UMTS))
Emergency call system control unit (model 205.047 with code 348 (Emergency call/assist system))
The information stored there can be retrieved using the smart phone, tablet or PC, for example. The information is provided by request only. The telematics services communications module (with code B57 (COM MODULE battery level)) sends the data via the communications module/stationary heater antenna splitter (with code B24 (Remote control for stationary heater)) and the communications module/stationary heater antenna. The HERMES control unit (model 205.013/047/053/054/147/213/247/253, model 253.311/354/911/954/99 with code 360 (HERMES UMTS)) transmits the data via the emergency call system antenna. On model 205.047 and with code 348 (Emergency call/assist system), the emergency call system control unit sends the data via the telephone antenna splitter, the left telephone antenna and the right telephone antenna. In the event of poor reception or a failure of the telephone antenna splitter, the left telephone antenna or the right telephone antenna, the emergency call system control unit automatically uses the emergency call system antenna to send and receive the mobile phone signals.
The auxiliary climate control comprises the following functions:
Auxiliary climate control via remote activation (model 205 with code 577 (Remote activation of heating and ventilation systems))
Auxiliary climate control via vehicle unlocking (model 205.012/013/047/053/054/147/212/213/247/253, model 253.311/354/911/954/99)
Auxiliary climate control at departure time (model 205.013/047/053/054/147/213/247/253, model 253.311/354/911/954/99)
Auxiliary climate control via auxiliary climate control button (model 205.013/047/053/054/147/213/247/253, model 253.311/354/911/954/99)
Start air quality improvement (with code P21 (Air Quality package))
Auxiliary climate control via remote activation (model 205 with code 577 (Remote activation of heating and ventilation systems))
The pre-entry climate control can be requested via the separate pre-entry climate control button on the transmitter key.
Vehicles without CODE (889) KEYLESS-GO and except CODE (893) KEYLESS-GO start function:
When the pre-entry climate control button is pressed, the transmitter key sends the access authorization code and the request to start the pre-entry climate control via the rear window antenna and the FM 1, AM, CL [ZV] and KEYLESS-GO antenna amplifier to the electronic ignition lock control unit. If the access authorization code is valid, the electronic ignition lock control unit sends the request for starting the pre-entry climate control via the interior CAN to the climate control control unit. The A/C control unit then starts the pre-entry climate control.
Vehicles with code (889) KEYLESS-GO or code (893) KEYLESS-GO start function:
When the pre-entry climate control button is pressed, the transmitter key sends the access authorization code and the request to start the pre-entry climate control via the rear window antenna and the FM 1, AM, CL [ZV] and KEYLESS-GO antenna amplifier to the KEYLESS-GO control unit. The KEYLESS-GO control unit sends this radio signal to the electronic ignition lock control unit via interior CAN.
If the access authorization code is valid, the electronic ignition lock control unit sends the request for starting the pre-entry climate control via the interior CAN to the climate control control unit. The A/C control unit then starts the pre-entry climate control.
To operate the pre-entry climate control, the A/C control unit assesses the outside temperature:
The outside temperature sensor measures the outside temperature. The front SAM control unit reads in the signal of the outside temperature sensor directly, calculates the outside temperature and transmits it to the A/C control unit over the interior CAN. The climate control control unit then evaluates the outside temperature.
The heating functions are activated at outside temperatures below 20 °C.
The ventilation functions are activated at outside temperatures above 20 °C.
If cooling is required, the following functions are started:
Automatic air conditioning
The climate control control unit sends the request to switch on the blower motor over the climate control LIN 2 to the blower regulator, which actuates the blower motor directly.
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 interior CAN to the rear SAM control unit.
The seat ventilation remains switched on even after starting the vehicle.
If cooling mode was activated, ventilation takes place for a maximum of 120 min. The cooling mode is terminated after this time has lapsed or when circuit 15 is switched on or when the vehicle is started.
If heating is required, the following functions are started:
Seat heater (with CODE 401 (Seat climate control for driver and front passenger) or CODE 873 (Seat heater for driver and front passenger))
The climate control control unit sends the request to switch on the seat heater via interior CAN to the rear SAM control unit.
The seat heating remains switched on even after starting the vehicle.
Steering wheel heater (with CODE 443 (Steering wheel heater))
The climate control control unit transmits the request for auxiliary climate control to the steering wheel electronics via the interior CAN, electronic ignition lock control unit, suspension FlexRay, steering column tube module control unit and steering LIN or steering wheel CAN.
The steering wheel heater also remains switched on after starting the vehicle.
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 also remains switched on after starting the vehicle.
If heating mode was activated, heating takes place for a maximum of 10 min. The heating mode is terminated after this time has lapsed or when circuit 15 is switched on or when the vehicle is started.
The pre-entry climate control can be activated two times if the on-board electrical system is sufficiently stable.
Additional function requirements for auxiliary climate control via vehicle unlocking (model 205.012/013/047/053/054/147/212/213/247/253, model 253.311/354/911/954/99)
Pre-entry climate control pre-configured via menu in head unit (model 205.012/212):
The head unit sends the status of the pre-entry climate control over the user interface CAN, electronic ignition lock control unit and the interior CAN to the climate control control unit.
Auxiliary climate control preset via menu in head unit and area (driver's side or vehicle interior) selected (model 205.013/047/053/054/147/213/247/253, model 253.311/354/911/954/99)
Auxiliary climate control via vehicle unlocking (model 205.012/013/047/053/054/147/212/213/247/253, model 253.311/354/911/954/99)
The objective of auxiliary climate control via unlocking (via transmitter key or KEYLESS-GO (with code 889 (KEYLESS-GO))) of the central locking system is to briefly preheat or preventilate the driver's side area (model 205.012/212) and/or the driver's side area or vehicle interior (model 205.013/047/053/054/147/213/247/253, model 253.311/354/911/954/99) when entering the vehicle and to precool the air from the air vents.
The electronic ignition lock control unit sends the status of the central locking over the interior CAN to the climate-control control unit. The climate control control unit checks the pre-configuration and then starts the pre-entry climate control.
To operate the pre-entry climate control, the climate control control unit assesses the following information:
Interior temperature in head area:
The interior temperature is recorded by the interior temperature sensor with integrated fan in the overhead control panel control unit. The overhead control panel control unit transmits information about the interior temperature to the climate control control unit via the interior CAN. The fan sucks in the air for temperature measurement from the vehicle interior.
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.
Model 205.012/212:
If the vehicle interior temperature is at least 4 °C above the set specified temperature, the vehicle is cooled. If the vehicle interior temperature is at least 4 °C below the set specified temperature, the vehicle is heated. If the lowest possible specified temperature is set on the climate control operating unit, the vehicle is always cooled. If the highest possible specified temperature is set on the climate control operating unit, the vehicle is always heated.
Model 205.013/047/053/054/147/213/247/253, model 253.311/354/911/954/99:
If the interior temperature is above the selected specified temperature, the vehicle is cooled. If the interior temperature is below the selected specified temperature, the vehicle is heated.
If cooling is required, the following functions are started:
Automatic air conditioning
The climate control control unit actuates the electric A/C compressor over the climate control LIN 2 and sends the request to switch on the blower motor over the climate control LIN 2 to the blower regulator, which then directly actuates the 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 interior CAN to the rear SAM control unit.
The seat ventilation remains switched on even after starting the vehicle.
If the cooling mode has been activated, cooling takes place for a maximum of 120 s (model 205.012/212) or 300 s (model 205.013/047/053/054/147/213/247/253, model 253.311/354/911/954/99). Cooling mode is ended after this time has expired, when the vehicle is started or when the auxiliary climate control button is pressed (model 205.013/047/053/054/147/213/247/253, model 253.311/354/911/954/99).
If heating is required, the following functions are started:
Automatic air conditioning (model 205.013/047/053/054/147/213/247/253, model 253.311/354/911/954/99)
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 coolant temperature is sent by the high voltage PTC heater over the 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 transmits the request to switch on the heating circuit circulation pump and the high-voltage PTC heater switchover valve to the high-voltage PTC heater via air conditioning control LIN 2. The high-voltage PTC heater switchover valve regulates the flow of coolant (small or large coolant circuit). The high-voltage PTC heater directly actuates the heater circuit circulation pump and the high-voltage PTC heater switchover valve.
The climate control control unit actuates the electric A/C compressor over the climate control LIN 2 and sends the request to switch on the blower motor over the climate control LIN 2 to the blower regulator, which then directly actuates the 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 12 °C and interior temperature deviation above 5 °C))
The climate control control unit sends the request to switch on the seat heater via interior CAN to the rear SAM control unit.
The seat heating remains switched on even after starting the vehicle.
Steering wheel heater (with CODE 443 (Steering wheel heater))
The climate control control unit transmits the request for auxiliary climate control to the steering wheel electronics via the interior CAN, electronic ignition lock control unit, suspension FlexRay, steering column tube module control unit and steering LIN or steering wheel CAN.
The steering wheel heater also remains switched on after starting the vehicle.
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 also remains switched on after starting the vehicle.
If the heating mode has been activated, heating takes place for a maximum of 120 s (model 205.012/212) or 300 s (model 205.013/047/053/054/147/213/247/253, model 253.311/354/911/954/99). Heating mode is ended after this time has expired, when the vehicle is started or when the auxiliary climate control button is pressed (model 205.013/047/053/054/147/213/247/253, model 253.311/354/911/954/99).
If the on-board electrical system is sufficiently stable, the auxiliary climate control can be activated once (model 205.012/212) or twice (model 205.013/047/053/054/147/213/247/253, model 253.311/354/911/954/99).
Additional function requirement for auxiliary climate control at departure time (model 205.013/047/053/054/147/213/247/253, model 253.311/354/911/954/99)
Pre-entry climate control pre-configured via menu in the head unit and the area (driver's side or vehicle interior) selected:
The head unit sends the "setting request" for pre-entry climate control over the user interface CAN, electronic ignition lock control unit and the interior CAN to the climate control control unit.
Pre-entry climate control pre-configured, e.g. through smartphone, tablet or PC
The telematics services communications module (with code B57 (COM MODULE battery level)) receives the data for web-based activation of the pre-entry climate control at departure time via the communications module/stationary heater antenna and the communications module/stationary heater antenna splitter (with code B24 (Remote control for stationary heater)). The HERMES control unit (model 205.013/047/053/054/147/213/247/253, model 253.311/354/911/954/99 with code 360 (HERMES UMTS)) receives the data via the emergency call system antenna. On model 205.047 and with code 348 (Emergency call/assist system), the emergency call system control unit sends the data for web-based activation of the pre-entry climate control at departure time via the left telephone antenna, the right telephone antenna and the telephone antenna splitter. In the event of poor reception or a failure of the telephone antenna splitter, the left telephone antenna or the right telephone antenna, the emergency call system control unit automatically uses the emergency call system antenna to send and receive the mobile phone signals. The telematics services communication module (with code B57 (Communication module battery charge level)), the HERMES control unit (model 205.013/047/053/054/147/213/247/253, model 253.311/354/911/954/99 with code 360 (HERMES UMTS)) or the emergency call system control unit (model 205.047 and with code 348 (Emergency call/assist system)) transmits the received requests to the climate control control unit via the diagnostics CAN, electronic ignition lock control unit and interior CAN.
Auxiliary climate control at departure time (model 205.013/047/053/054/147/213/247/253, model 253.311/354/911/954/99)
The objective of the pre-entry climate control at departure time is to pre-heat or pre-cool the vehicle interior prior to departure.
Set a departure time:
The departure time can be set, selected and activated via the menu structure in the instrument cluster or web-based via a browser, e.g. using a smartphone, a tablet or a PC. Up to three departure times can be configured.
Activating the departure time via the instrument cluster:
The instrument cluster transmits the activated departure time via the user interface CAN, electronic ignition lock control unit and interior CAN to the climate control control unit. The climate control control unit calculates the required starting time for the pre-entry climate control and sends this via the interior CAN, electronic ignition lock control unit, and chassis FlexRay to the powertrain control unit. When the starting time is reached, the powertrain control unit sends the request for pre-entry climate control via chassis FlexRay, electronic ignition lock control unit and interior CAN to the climate control control unit.
Activating the departure time, e.g. with a smartphone, a tablet or a PC:
The telematics services communications module (with code B57 (COM MODULE battery level)) receives the corresponding requests for web-based programming of the departure time via the communications module/stationary heater antenna and the communications module/stationary heater antenna splitter (with code B24 (Remote control for stationary heater)).
In the case of web-based programming, the HERMES control unit (model 205.013/047/053/054/147/213/247/253, model 253.311/354/911/954/99 with code 360 (HERMES UMTS)) receives the requests via the emergency call system antenna.
On model 205.047 with code 348 (Emergency call/assist system), the emergency call system control unit receives the corresponding requests for web-based programming of the departure time via the emergency call system antenna and via the left telephone antenna, the right telephone antenna and the telephone antenna splitter. In the event of poor reception or a failure of the telephone antenna splitter, the left telephone antenna or the right telephone antenna, the emergency call system control unit automatically uses the emergency call system antenna to send and receive the mobile phone signals.
The telematics services communication module (with code B57 (Communication module battery charge level)), the HERMES control unit (model 205.013/047/053/054/147/213/247/253, model 253.311/354/911/954/99 with code 360 (HERMES UMTS)) or the emergency call system control unit (model 205.047 and with code 348 (Emergency call/assist system)) transmits the received requests to the powertrain control unit via the diagnostics CAN, electronic ignition lock control unit and suspension FlexRay. The powertrain control unit then sends the activated departure time via chassis FlexRay, electronic ignition lock control unit and user interface CAN to the instrument cluster, which stores this. The climate control control unit calculates the required starting time for the pre-entry climate control and sends this via the interior CAN, electronic ignition lock control unit, and chassis FlexRay to the powertrain control unit. When the starting time is reached, the powertrain control unit sends the request for pre-entry climate control via chassis FlexRay, electronic ignition lock control unit and interior CAN to the climate control control unit.
When the departure time is activated, the LED in the pre-entry climate control button lights up yellow. The request to switch on the LED is transmitted by the powertrain control unit via chassis FlexRay, electronic ignition lock control unit, interior CAN, climate control control unit and the climate control LIN to the climate control operating unit. The climate control operating unit actuates the LED in the pre-entry climate control button directly.
To operate the pre-entry climate control at the departure time, the climate control control unit assesses the following information:
Interior temperature in head area:
The interior temperature is recorded by the interior temperature sensor with integrated fan in the overhead control panel control unit. The overhead control panel control unit transmits information about the interior temperature to the climate control control unit via the interior CAN. The fan sucks in the air for temperature measurement from the vehicle interior.
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 of the outside temperature sensor directly, calculates the outside temperature and transmits it to the A/C control unit over the interior CAN.
Solar radiation:
The sun sensor integrated in the rain/light sensor with additional functions records the angle of incidence and the intensity of the solar radiation. The signals of the rain/light sensor with additional functions are read in by the front SAM control unit via the rain/light sensor LIN. The front SAM control unit sends the signals over the interior CAN to the A/C 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 above the selected specified temperature, the vehicle is cooled. If the interior temperature is below the selected specified temperature, the vehicle is heated.
If cooling is required, the following functions are started:
Automatic air conditioning
The climate control control unit actuates the electric A/C compressor over the climate control LIN 2 and sends the request to switch on the blower motor over the climate control LIN 2 to the blower regulator, which then directly actuates the 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 interior CAN to the rear SAM control unit.
The seat ventilation remains switched on even after starting the vehicle.
If heating is required, the following functions are started:
Automatic air conditioning
The climate control control unit actuates the electric A/C compressor over the climate control LIN 2 and sends the request to switch on the blower motor over the climate control LIN 2 to the blower regulator, which then directly actuates the blower motor. The refrigerant compressor is activated in order to ensure that the air flowing out is dried, thus preventing fogging of the windows.
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 coolant temperature is sent by the high voltage PTC heater over the 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 transmits the request to switch on the heating circuit circulation pump and the high-voltage PTC heater switchover valve to the high-voltage PTC heater via air conditioning control LIN 2. The high-voltage PTC heater switchover valve regulates the flow of coolant (small or large coolant circuit). The high-voltage PTC heater directly actuates the heater circuit circulation pump and the high-voltage PTC heater switchover valve.
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 12 °C and interior temperature deviation above 5 °C))
The climate control control unit sends the request to switch on the seat heater via interior CAN to the rear SAM control unit.
The seat heating remains switched on even after starting the vehicle.
Steering wheel heater (with CODE 443 (Steering wheel heater))
The climate control control unit transmits the request for auxiliary climate control to the steering wheel electronics via the interior CAN, electronic ignition lock control unit, suspension FlexRay, steering column tube module control unit and steering LIN or steering wheel CAN.
The steering wheel heater also remains switched on after starting the vehicle.
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 also remains switched on after starting the vehicle.
The steering wheel heater and the mirror heater are actuated for max. 8 min and the seat heater and the rear window heater for max. 13 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. The vehicle interior then continues to be air-conditioned and the temperature is maintained. For this purpose, pre-entry climate control is activated max. 55 min. 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.
Even if the vehicle is connected to power supply equipment and the high-voltage battery was completely charged, the high-voltage battery can discharge during pre-entry climate control.
Auxiliary climate control is ended when the vehicle is started, when the auxiliary climate control button is pressed or if 5 min have passed since the selected departure time expired.
Auxiliary climate control via auxiliary climate control button (model 205.013/047/053/054/147/213/247/253, model 253.311/354/911/954/99)
The pre-entry climate control can also be switched on after 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 auxiliary climate control is switched on and off by pressing the auxiliary climate control button in the air conditioning control panel. 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.
Using the indicator lamps in the pre-entry climate control button, the current operating condition of the pre-entry climate control is shown:
Indicator lamp illuminates in red: Heating is switched on
Indicator lamp illuminates in blue: Cooling is switched on
Indicator lamp illuminates in yellow: Departure time is preselected
The request to switch on the indicator lamp is transmitted by the powertrain control unit via chassis FlexRay, electronic ignition lock control unit, interior CAN, climate control control unit and the climate control LIN to the climate control operating unit. The climate control operating unit actuates the LED in the pre-entry climate control button directly.
To operate the auxiliary climate control by pressing the auxiliary climate control button, the climate control control unit assesses the following information:
Interior temperature in head area:
The interior temperature is recorded by the interior temperature sensor with integrated fan in the overhead control panel control unit. The overhead control panel control unit transmits information about the interior temperature to the climate control control unit via the interior CAN. The fan sucks in the air for temperature measurement from the vehicle interior.
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 of the outside temperature sensor directly, calculates the outside temperature and transmits it to the A/C control unit over the interior CAN.
Solar radiation:
The sun sensor integrated in the rain/light sensor with additional functions records the angle of incidence and the intensity of the solar radiation. The signals of the rain/light sensor with additional functions are read in by the front SAM control unit via the rain/light sensor LIN. The front SAM control unit sends the signals over the interior CAN to the A/C 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 cooling is required, the following functions are started:
Automatic air conditioning
The climate control control unit actuates the electric A/C compressor over the climate control LIN 2 and sends the request to switch on the blower motor over the climate control LIN 2 to the blower regulator, which then directly actuates the 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 interior CAN to the rear SAM control unit.
The seat ventilation remains switched on even after starting the vehicle.
If heating is required, the following functions are started:
Automatic air conditioning
The climate control control unit actuates the electric A/C compressor over the climate control LIN 2 and sends the request to switch on the blower motor over the climate control LIN 2 to the blower regulator, which then directly actuates the blower motor. The refrigerant compressor is activated in order to ensure that the air flowing out is dried, thus preventing fogging of the windows.
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 coolant temperature is sent by the high voltage PTC heater over the 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 transmits the request to switch on the heating circuit circulation pump and the high-voltage PTC heater switchover valve to the high-voltage PTC heater via air conditioning control LIN 2. The high-voltage PTC heater switchover valve regulates the flow of coolant (small or large coolant circuit). The high-voltage PTC heater directly actuates the heater circuit circulation pump and the high-voltage PTC heater switchover valve.
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 12 °C and interior temperature deviation above 5 °C))
The climate control control unit sends the request to switch on the seat heater via interior CAN to the rear SAM control unit.
The seat heating remains switched on even after starting the vehicle.
Steering wheel heater (with CODE 443 (Steering wheel heater))
The climate control control unit transmits the request for auxiliary climate control to the steering wheel electronics via the interior CAN, electronic ignition lock control unit, suspension FlexRay, steering column tube module control unit and steering LIN or steering wheel CAN.
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 also remains switched on after starting the vehicle.
Additional function requirements for starting air quality improvement (with code P21 (Air Quality package))
Ionization was activated during the latest ignition cycle via the menu in the head unit:
The head unit sends the status of the ionization via user interface CAN, electronic ignition lock control unit and the interior CAN to the climate control control unit.
Fragrancing was activated during the latest ignition cycle via the menu in the head unit:
The head unit sends the status of the fragrancing via user interface CAN, electronic ignition lock control unit and the interior CAN to the climate control control unit.
Start 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 activated via the operation menu in the head unit:
Ionization
Fragrancing
Both functions cannot be selected separately. Even if the vehicle is neither cooled nor ventilated based on the evaluation of the environmental data, both functions are activated at the time that is included in the function sequence for the corresponding type of activation of the pre-entry climate control and switched off after 60 s. On model 205 with code 577 (Remote activation of heating and ventilation systems), both functions are switched off after a period of 10 min (heating) or 5 min (cooling).
Ionization and fragrancing remain switched on even after starting the vehicle.