GF83.70-P-3066GZ Activate Heater With Stationary Heater Switch, Function

GF83.70-P-3066GZ Activate Heater With Stationary Heater Switch, Function
- Only ECE-cars

Component Identification:

Function requirements:
^ Circuit 30
^ Fuel gauge is not in reserve

Function
After actuation of the STH switch, the upper control panel control unit sends the signal for switching on the stationary heater to the STH control unit via CAN-B.
Thereupon, the STH control unit transmits a query to the AAC [KLA] control and operating unit via CAN-B 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