Outside temperature sensor (coding-dependent) The instrument cluster determines the current outside temperature with the aid of the outside temperature sensor (NTC resistor). The outside temperature sensor is connected by a separate ground (analog ground) and a sensor line (analog positive) to the instrument cluster. The outside temperature is only indicated when a steering column switch with on-board computer function key is installed.
The instrument cluster sends the ”outside temperature” information via the body bus (K-bus). In ignition lock position ”0”, the outside temperature sensor is read by the instrument cluster at time intervals which are within the minute range. For this purpose, the instrument cluster is temporarily activated, provides the information and then switches itself off again.
Outside temperature warning (coding-dependent) If, while driving, the outside temperature drops below +3 oC, depending on the coding, a warning signal (code-dependent gong or acoustic generator) is triggered and the display changes from the current indication mode to the outside temperature display with the displayed value flashing for 8 seconds. If the outside temperature display is reactivated with the on-board computer function button on the steering lock switch with the outside temperature warning still active, the display will flash again but no acoustic warning is now signalled. If the outside temperature increases to above + 3 oC while driving, the outside temperature display is shown and does not flash. The outside temperature warning is only activated again after exceeding a temperature of + 6 oC and then again dropping below + 3 o C.
Outside temperature display (code-dependent) The unit of temperature display (o C/o F) is defined in the coding data. However, it is possible to change over the unit of display from o C to o F and from o F to o C by pressing the right-hand button in the instrument cluster while the outside temperature is displayed. The unit display selected is retained for as long as supply voltage is applied to the instrument cluster and no reset is triggered.
The display range extends from 40 oC to +50 oC. An increasing outside temperature display is damped since heat from the engine and other ambient conditions influence the outside temperature display. A drop in the outside temperature is not damped.
The instrument cluster sends the ”outside temperature” information via the body bus (K-bus). In ignition lock position ”0”, the outside temperature sensor is read by the instrument cluster at time intervals which are within the minute range. For this purpose, the instrument cluster is temporarily activated, provides the information and then switches itself off again.