Part 1
GF83.70-P-0006CE Stationary Heater (STH), Function
MODEL 204
- with CODE (228) Stationary heater
A1 Instrument cluster
A1p13 Multifunction display
A2/53 Mobile phone antenna splitter and stationary heater radio remote control (with code (386) Comfort telephony)
A6 Stationary heater unit
A6b1 Stationary heater temperature sensor
A6f1 Stationary heater thermal fuse
A6m2 Stationary heater combustion air blower
A6n1 Stationary heater control unit
A6r4 Stationary heater glow plug/ flame monitor unit
A6r5 Stationary heater fuel preheater heating element (diesel engine)
A6y2 Stationary heater fuel shutoff valve (diesel engine)
A6/1 Stationary heater radio remote control receiver
A8/3 Stationary heater radio remote control transmitter
A28/11 Multifunction antenna
A32m1 Blower motor
A32n1 Blower regulator
B10/4 Interior temperature sensor
B14 Outside temperature sensor
M13/5 Coolant circulation pump
N2/10 Supplemental restraint system control unit
N3/9 CDI control unit (with diesel engine)
N3/10 ME-SFI [ME] control unit (with gasoline engine)
N10/1 Front SAM control unit with fuse and relay module
N22/7 Automatic air conditioning control and operating unit
N70 Overhead control panel control unit
N70b1 Interior temperature sensor with integrated fan (with code (414) Power glass tilting/sliding roof)
N70/3 Overhead control panel electronics
N70/3b1 Interior temperature sensor with integrated fan (without code (414) Power glass tilting/ sliding roof)
N72/1 Upper control panel control unit
N72/1s30 Stationary heater button
N73 Electronic ignition switch control unit
Y16 Stationary heater switchover valve
Y23 Stationary heater fuel pump
CAN B Interior CAN
CAN E Chassis CAN
LIN 1 Instrument panel LIN
Stationary heater (STH), general
In cold seasons before commencing a journey, the stationary heater ensures:
- the interior compartment is preheated
- the windows are free of ice and condensation
- the engine is preheated
The use of the stationary heater reduces:
- the accident hazard by providing clear visibility before starting out on a trip
- the mechanical wear to the automotive engine associated with a cold start
- fuel consumption and at the same time it also helps to protect the environment by reducing the pollutants in the exhaust when starting up a preheated engine
The stationary heater also contains the stationary ventilation function.
This provides for the following at high ambient temperatures and a high interior temperature due to intense solar radiation:
- the interior is ventilated
- stored heat is reduced
It is not possible to reduce the temperature below the level of the outside temperature.
The stationary heater can be switched on as follows:
- Immediately via the stationary heater button or the radio remote control transmitter
- preprogrammed via the menu structure in the instrument cluster or the radio remote control transmitter
The central component of the stationary heater is the heater unit that contains all necessary components for generating and exchanging heat.
The heater unit is integrated directly into the engine's heating and cooling circuit and is supplied with fuel by the stationary heater fuel pump.
The stationary heater enables the interior temperature of the vehicle to be increased according to the request.
The operation of the stationary heater requires the determination of the following temperatures:
- Outside temperature (for calculation of the heating duration with a programmed departure time)
- Interior temperature (in roof area)
- Interior temperature in instrument panel area
Outside temperature:
The outside temperature is recorded by the outside temperature sensor. The front SAM control unit directly reads in the signal of the outside temperature sensor, calculates the outside temperature and sends it to the unit and operating unit via interior CAN.
Interior temperature in area of roof, On vehicles with code (414) Power glass tilting/sliding roof:
The interior temperature is measured by the interior temperature sensor with integrated fan (N70b1).
The overhead control panel control unit reads in the signals from the interior temperature sensor directly and sends them to the control and operating unit via interior CAN.
Interior temperature in area of roof, On vehicles without code (414) Power glass tilting/sliding roof:
The interior temperature is measured by the interior temperature sensor with integrated fan (N70/3b1).
The control and operating unit reads in the signals of the interior temperature sensor directly.
Interior temperature in area of instrument panel:
The interior temperature is recorded by the interior temperature sensor.
The control and operating unit reads in the signals of the interior temperature sensor directly.
The stationary heater encompasses the following subfunctions:
^ Function sequence for teaching in radio remote control transmitter
^ Function sequence for operation with the radio remote control transmitter
^ Function sequence for checking the component status
^ Function sequence for activating ventilation or heating
^ Function sequence for ventilation or heating mode
^ Function sequence for triggering immediate mode
^ Function sequence for programming the departure time
^ Function sequence for triggering ventilation/heating mode for the departure time
^ Function sequence, STH shutoff
Additional function requirements, function sequence for teaching in radio remote control transmitter
^ Circuit 30 ON or
^ Circuit 15C ON
The electronic ignition lock control unit sends the status of circuit 15C via interior CAN to the stationary heater control unit.
Function sequence for teaching in radio remote control transmitter
The individual components have already been matched to each other at the factory. Teaching in is only necessary upon exchange of the heater unit or of the radio remote control receiver or the radio remote control transmitter.
To teach in the radio remote control transmitter, press the stationary heater button in the upper control panel control unit for approx. t = 20 s. The radio remote control receiver opens the teach-in window for max. t = 5 s.
If the red indicator lamp in the air heater button flashes, press the "OFF" button until the "OFF" message is shown in the display (at least t=1s).
The radio remote control transmitter then sends a radio signal.The radio remote control receiver receives this radio signal and stores the radio remote control transmitter as assigned to it. The radio remote control receiver then closes the teach-in window. To teach in an additional radio remote control transmitter, the teach-in window must be opened again.
The radio remote control receiver can store up to three radio remote control transmitters. If a fourth radio remote control transmitter is to be taught in, the first radio remote control transmitter that was taught in is deleted.
Using the diagnostic tester the teach-in window can be opened, the time period of which can be configured and the number of radio remote control transmitters that have undergone teach-in can then be read out
The upper control panel control unit evaluates the air heater button and sends this via instrument panel LIN, front SAM control unit and interior CAN to the stationary heater control unit. The stationary heater control unit sends the request to open the teach- in window to the radio remote control receiver.
With the teach-in window open, the stationary heater control unit sends a corresponding signal via interior CAN, front SAM control unit and instrument panel LIN to the upper control panel control unit. The upper control panel control unit actuates the indicator lamp in the stationary heater button.
Vehicles without code (386) Comfort telephony:
The radio remote control receiver receives the radio signals of the radio remote control transmitter directly via the multifunction antenna.
Vehicles with code (386) Comfort telephony:
The radio remote control receiver receives the radio signals of the radio remote control transmitter via the mobile phone and stationary heater radio remote control antenna splitter and the multifunction antenna.
Function sequence for operation with the radio remote control transmitter
When pressing the "ON" button on the radio remote control transmitter, this emits a radio signal (switch-on signal).
The stationary heater control unit receives this switch-on signal and starts the "Ventilate" or "Heat" query to the control and operating unit. The stationary heater is the activated accordingly.
In addition, the radio remote control receiver stores the current operating condition of the stationary heater.
The stationary heater control unit then sends information on the operating condition of the stationary heater to the radio remote control receiver, which can then be called up via the radio remote control transmitter.
This information is provided exclusively upon request via the radio remote control transmitter.
The range of the radio remote control transmitter is maximum s = 300 m (outdoors).
The following influences can reduce the maximum range:
- radio interference
- solid obstacles (e.g. enclosed premises)
- unfavorable position to the vehicle
Vehicles without code (386) Comfort telephony:
The radio remote control receiver receives the radio signals of the radio remote control transmitter directly via the multifunction antenna.
Vehicles with code (386) Comfort telephony:
The radio remote control receiver receives the radio signals of the radio remote control transmitter via the mobile phone and stationary heater radio remote control antenna splitter and the multifunction antenna.
The stationary heater control unit reads in the switch-on signal via the radio remote control receiver and sends the "Ventilate" or "Heat" query via interior CAN to the control and operating unit.
The radio signal path is bidirectional, i.e. if the radio signal does not reach the radio remote control receiver, this is displayed at the radio remote control transmitter.
The following functions can be operated using the radio remote control transmitter:
- Trigger immediate mode
- Call up departure time
- Set departure time
- Activate departure time
- Deactivate departure time
- Call up the operating condition of the stationary heater
The individual requests are stored in the stationary heater control unit.
Trigger immediate mode:
Press the "ON" button once.
The ventilation or heating mode is started depending on the temperature level.
Call up departure time:
Press one of the arrow keys on the radio remote control transmitter once. The operating condition of the stationary heater is shown in the display. Press the "right" arrow key.
The first of three possible departure times is shown.
Press the "right" arrow key again.
The second departure time is shown.
Press the "right" arrow key once again.
The third departure time is shown.
The departure times are shown in the radio remote control transmitter upon request, not stored.
Set departure time:
If the desired departure time is not displayed, this can be programmed in setting mode.
Press the "ON" and "OFF" buttons at the same time for this (within t < 0.7 s). The clock symbol in the display flashes. The departure time can now be set using the arrow keys. To adopt the newly set departure time, press the "ON" and "OFF" buttons again at the same time.
Activate departure time:
To activate a departure time, the "ON" button must be pressed after calling up the desired time.
Deactivate departure time:
To deactivate a departure time, the "OFF" button must be pressed after calling up the desired time.
The operating condition of the stationary heater is shown in the display of the radio remote control transmitter.
Call up the operating condition of the stationary heater:
Press one of the arrow keys on the radio remote control transmitter once. The operating condition of the stationary heater is shown in the display of the radio remote control transmitter.
The possible displays are listed in the separate description "Stationary heater radio remote control transmitter, component description". The display time can be set via diagnostic tester in the stationary heater control unit in 2-second intervals (t = 4 and 30 s).