GF83.70-P-3058GZ Activate Preprogrammed Heater, Function

GF83.70-P-3058GZ Activate Preprogrammed Heater, Function

Component Identification:

The starting time of the stationary heater is set in the instrument cluster via the stationary heater menu. The starting time is set with the left or right multifunction steering wheel button group and can be activated by selecting the corresponding starting time.
Once the starting time is activated, visual confirmation is provided via a continuously on yellow indicator lamp in the STH switch. The instrument cluster stores a maximum of 3 starting times.

Function requirement
^ Circuit 15R ON
^ Starting time in the instrument cluster activated
^ Fuel gauge is not in reserve

Function
When the set starting time has been reached, the instrument cluster sends the switch-on signal to the STH control unit via CAN-B.
Thereupon, the STH control unit transmits, via CAN-B, a query to the AAC [KLA] control and operating unit to check whether heating or ventilating is required.
The AAC [KLA] control and operating unit determines, depending on the target temperature last set on the operating unit, whether heating or ventilating is required and returns the corresponding message to the STH control unit.

During operation, the AAC [KLA] control and operating unit can switch over between heating and ventilating any number of times to obtain the desired target temperature irrespective of outside temperature and solar radiation. Visual confirmation is provided by an indicator lamp in the STH switch:
^ Blue: vehicle is ventilated
^ Red: vehicle is heated

Heating mode
The STH control unit switches the auxiliary heater metering pump as well as the STH switchover valve on and actuates the blower motor. The coolant circulation pump is actuated by the AAC [KLA] control and operating unit.

To obtain the set target temperature in the interior as quickly as possible, the STH control unit regulates the coolant flow between the small and the large coolant circuit heated by the STH heater unit (A6) dependent on the temperature via the STH switchover valve.
The coolant circulation pump ensures that the temperature- controlled coolant is circulated in the coolant circuit.

Ventilation
The STH control unit only actuates the blower motor.

Operating time for heater and ventilation
In the basic setting, the maximum heating time is 50 min. It is possible to change it via diagnosis in 10 min increments between 10 and 60 min.
The maximum ventilation time is limited to a maximum of 50 min in the basic setting, as is the heating time, unless a shortening factor was set via diagnosis.
The following shortening factors can be set:
^ Factor 1: ventilation time = 1/3 heating time
^ Factor 2: ventilation time = 1/2 heating time
^ Factor 3: ventilation time = 1/4 heating time