Activate preprogrammed heater, function - GF83.70-P-3058T

MODEL 211.0/2/6 with CODE (228) Stationary heater 

Enter preselected time 

Function requirements: 

• Term. 15R

Function 

The starting time for the stationary heater is set in the instrument cluster via the stationary heater menu. The starting time is entered and actuated with the aid of the multifunction steering wheel button groups. Up to 3 starting times can be stored. Following selection, the starting time is automatically activated. Activation is indicated by the yellow indicator lamp in the STH switch. The starting time is stored in the instrument cluster.

The preselected times currently stored in the instrument cluster are suppressed if the heater operation has been manually switched on.

Stationary heater start upon reaching the preselected time 

Function requirements 

• C. 15 OFF
• Sufficient remaining quantity of fuel in tank

Function 

When the preselected time is reached, the yellow indicator lamp goes out and the instrument cluster transmits the switch-on request to the STH control unit. This then initiates the "Ventilate or heat" query via CAN-B to the AAC [KLA] control unit. The AAC [KLA] control unit determines the current interior and outside temperature.

Depending on the values determined and the last setting of the AAC [KLA] control unit, the AAC [KLA] control unit makes a decision either for heating or ventilation and then transmits the decision to the STH control unit.

If the decision is for heating, a query on the status of all components involved in the heater operation is conducted and a self-test is performed if required. The heater operation is not started in the event of a relevant fault. However, the stationary ventilation function is always performed, irrespective of the result.

Heating decision 

The fuel metering pump is actuated to supply fuel and the heater unit starts heater operation.

To enable the interior to be heated up faster, the heater unit regulates the flow of coolant, depending on the temperature, between the small and large coolant circuit via the switchover valve. The coolant circulation pump ensures that the temperature-controlled coolant is circulated in the coolant circuit.

When the temperature is at a sufficient level, the AAC [KLA] control unit actuates the blower motor via the blower regulator.

Ventilation decision 

During stationary ventilation only the blower is actuated in the vehicle.

The AAC [KLA] control unit actuates the blower motor via the blower regulator.

Depending on the interior temperature, a switchover from stationary heating to stationary ventilation and vice versa can be made.

Status indicator 

The red indicator lamp in the STH switch indicates stationary heating, and the blue lamp indicates stationary ventilation.

STH heater unit component description	A6	GF83.70-P-4202T
Stationary heater/heater booster control unit, location/task	A6n1	GF83.70-P-4002T
STH switchover valve component description	A6y1	GF83.70-P-4205T
Blower motor, location/task/function	A32m1	GF83.10-P-2140T
Blower regulator, location/task/function	A32n1	GF83.10-P-2141T
In-car temperature sensor with ventilation fan, location/purpose/function	B10/4	GF83.57-P-2107T
Outside temperature sensor, location/task/function	B14	GF83.57-P-2110T
Heater water circulation pump, location/task/function	M13	GF83.20-P-2109T
Driver-side SAM control unit with fuse and relay module, location/task/design	N10/1	GF54.21-P-4109T
Front passenger-side SAM control unit with fuse and relay module, location/task/design	N10/11	GF54.21-P-4111T
Control and operating unit for automatic air conditioning, location/task	N22 Vehicles without code (581) Comfort automatic air conditioning	GF83.40-P-2180T
Comfort automatic air conditioning control and operating unit, location/task	N22/7 Vehicles with code (581) Comfort automatic air conditioning	GF83.40-P-2181TT
Stationary heater switch, location/task	N72s12	GF83.70-P-4056T
STH fuel metering pump component description	Y23	GF83.70-P-4203T