GF83.70-P-2001Q Heater Operation, Function

GF83.70-P-2001Q Heater operation, function
- with CODE (228) Stationary heater [models 209.3 as of 1.6.04]


Requirement
Request of "heater operation" by
^ STH radio remote control transmitter (A8/3) or
^ STH switch (N72s12) or
^ Instrument cluster (A1) (timer setting)
is present.

Heating function
^ The red LED in the STH switch (N72s12) indicates by means of a steady light that heating mode has been triggered.
^ The AAC [KLA] control and operating unit (N22) in vehicles without code (581) Comfort automatic air conditioning or the comfort AAC control and operating unit (N22/7) in vehicles with code (581) Comfort automatic air conditioning transmits the "Heat" signal to the STH control unit (A6n1) via the Controller Area Network Bus class B (interior) (CAN-B) and switches to stationary heating mode. The flaps in the air conditioner housing are moved to the "Heat" position and the circulation pump (A6m1) is actuated by the STH control unit (A6n1).
^ The STH control unit (A6n1) activates STH heater unit (A6) heating operation.
^ If the temperature sensor (A6b1) that is a fixed constituent of the STH heater unit (A6) detects an adequate coolant temperature value, the STH control unit (A6n1) relays the "Blower ON" command to the AAC [KLA] control and operating unit (N22) or the comfort AAC control and operating unit (N22/7) via CAN-B. This actuates the blower motor (A32m1) via the blower regulator (A32n1).

During heating operation, the temperature is controlled by means of different actuations (partial load, full load) of the STH fuel metering pump (Y23) and the combustion air blower (A6m2) by the STH control unit (A6n1).

Automatic stop of heater operation
^ When the heating duration elapses (basic value 50 min, via STAR DIAGNOSIS in steps of 10 min, adjustable between 10 min and 60 min).

Manual ending of heater operation
^ Operate "OFF" button at STH radio remote control transmitter (A8/3).

vehicles as of 1.12.04 the correct reception of the switch-off signal by the STH radio remote control receiver (A6/1) is confirmed on the STH radio remote control transmitter (A8/3). If the wireless connection is OK, the LED illuminates with a steady red light for 2 seconds after the time of signal transmission. If the wireless connection is not OK, the LED flashes red for 2 seconds.

^ Operate STH switch (N72s12).

The indicator lamp in the STH switch (N72s12) extinguishes at the end of heating operation.
The STH heater unit (A6) then goes into power-down mode. xxx

Emergency shutoff
A thermal fuse that is a fixed constituent of the STH control unit (A6n1) switches off the STH heater unit (A6) if a critical temperature threshold is exceeded.