GF83.70-D-2008HZ Trigger Heating Mode, Function

GF83.70-D-2008HZ Trigger Heating Mode, Function
MODEL 906.111 /113 /131 /133 /135 /153 /155 /211 /213 /231 /233 /235 /253 /255 /611 /613 /631 /633 /635 /637 /653 /655 /657 /711 /713 /731 /733 /735
- with CODE (HZ9) Heater booster, diesel
- Heater booster (ZUH)

MODEL 906.611 /613 /631 /633 /635 /637 /653 /655 /657 /711 /713 /731 /733 /735
- with CODE (HZ5) 10 kW warm water auxiliary heater with timer
- Heater booster (ZUH)

On vehicles with code (HZ9) Heater booster, diesel, pressing the stationary heater switch (S46/10) in the upper subfield activates the heater operation of the heater booster heater unit when the engine is running with "terminal 61 ON" via the warm water auxiliary heater 2 (N33/2). The signal of the stationary heater switch is control unit directly read in by the warm water auxiliary heater 2 control unit via a discrete line.

New USA exhaust emission legislation as of 01/2010:
Operation of the stationary heater is only possible with outside temperatures < 4 °C (39.2 °F).

On vehicles with code (HZ5) 10 kW warm water auxiliary heater with timer, pressing the warm water stationary heater switch (S46/11) in the lower subfield activates the heater operation of the heater booster heater unit when the engine is running with "terminal 61 ON".
The signal of the warm water stationary heater switch is directly read in by the warm water auxiliary heating control unit (N33/3) via a discrete line and then forwarded to the warm water auxiliary heater 2 control unit.

The stationary heater switch has a "Memory function" (automatic heater operation activation of the heater booster heater unit). The "Memory function" remains active (also in the event of a status change of circuit 15 and circuit 61) until it is deactivated again by operating the stationary heater switch in the upper subfield.

The warm water auxiliary heater 2 control unit reads in the signal directly or via the warm water auxiliary heating control unit and then actuates the following components needed for the heater operation of the heater booster heater unit:
- Blower motor (N33/2m1) of the ZUH combustion air blower, for combustion air supply
- Glow pin (N33/2r1), for preheating the burner housing and for ignition of the fuel
- Metering pump (M46/4), for fuel supply
- Circulation pump (M13/4), to circulate the coolant

In addition, the warm water auxiliary heater 2 control unit places the message "ZHZ_EIN (heater booster switched on)" on the Controller Area Network bus class B (interior) (CAN-B) and permanently actuates the red light emitting diode (LED) integrated in the stationary heater switch directly via a discrete line on vehicles with code (HZ9) Heater booster, diesel.
On vehicles with code (HZ5) 10 kW warm water auxiliary heater with timer, the warm water auxiliary heater 2 control unit permanently actuates the red LED integrated in the warm water stationary heater switch via the warm water auxiliary heating control unit.