Inclusion
Additional or auxiliary heater can be switched on by remote control. Immediate heating button -E537- if programmed accordingly in the infotainment system menu or directly on the air conditioning control panel. The vehicle electronics automatically starts the additional or auxiliary heater if all the necessary conditions for this are met. The function of the fresh air blower -V2-H of the combination glow plug with ignition control system -Q8- is first checked, after which the glow plug with ignition control system -Q8- goes through the preheating phase. The subsequent start-up process depends on the coolant temperature and may vary in duration. Next, fuel is supplied, the glow plug with ignition control system -Q8- is switched off in stages and the flame control sensor is activated. After the end of the pre-glow, the device starts at full power and further load control (combustion mode, full load, partial load and regulation pause) via coolant temperature thresholds: changeover from full load to partial load: approx. 82°C; switching from partial load to regulation pause: approx. 88°C. If the coolant temperature falls below 71°C during the control pause of 15 minutes, the heater switches back to full load mode. To compensate for changes due to aging, the reference resistance of the ignition-monitoring glow plug -Q8- is determined automatically at regular intervals, depending on the device, during the start-up or after-run phase. During these calibration processes, the corresponding functions can also take a long time.
Shutdown
The additional or auxiliary heater is switched off after the maximum possible operating period of 60 minutes has elapsed or when switched off manually using the remote control or the immediate heating button -E537-. The auxiliary or auxiliary heater is switched off if at least one of the pre-set switching conditions is not fulfilled. After switching off, the metering pump -V54- is directly adjusted. The operation of the combustion air blower -V6- and the glow plug with ignition control -Q8- is temporarily limited in order to completely burn out the remaining fuel in the system and to cool down the burner components. The after-run of the circulation pump -V55- continues. The inertial run-out of the heater can be different, depending on the software version and the load level at the time of shutdown: 175 seconds when turning off from full load mode, 110 seconds when turning off from partial load mode. Depending on the software version of the control unit, there may be deviations in the specified durations of the operating phase after switching off.
Removing and installing radio signal receiver for auxiliary water heater -R149-
The radio signal receiver for the additional heater -R149- is located behind the left side trim in the luggage compartment. Remove left luggage compartment trim. Disconnect aerial connector -1- and connector -2-. Press tab -3- and push radio receiver out of bracket -arrow-.
Installation in reverse order.
Note: When replacing the receiver, adapt the new receiver to the heater using the Tester in the "Guided Fault Finding" mode".