Outside Temperature

Outside Temperature Measurement And Display Components

An outside air temperature sensor in the area of the bumper measures the outside temperature. The temperature value is sent to the instrument cluster across conventional cables.

The input value of the temperature sensor is computed in the control module of the instrument cluster against the current engine temperature (coolant temperature) and the vehicle speed.

This ensures that the outside temperature signal is not excessively falsified by the air flow and/or the engine heat.

The instrument cluster makes this outside temperature mean value available to the other control modules as a telegram via the K-CAN SYSTEM.

The instrument cluster is thus the "outside temperature master" for the control modules in the chassis and suspension, drive and body sections.

Control panels

Steering column switch center
The onboard computer and Check Control displays can be called up and scrolled through with the buttons on the turn indicator and low beam switch.

Controller
The Controller can be used via the Control Display to change the units of the temperature gauge ( degree C, degree F). The display can also be coded using the Tester.

Trip odometer reset button
The trip distance reset button on the instrument cluster can be used with the ignition switched off to call up displays and functions.
- A brief press displays the outside temperature for eight seconds and
- a long press (> two seconds) activates the test functions.

Display areas

Within the speedometer
In this display area, the diagnostic test functions can be called up:
- Switch terminal R or
- terminal 15 on or
- switch terminal 15 off, hold the trip distance reset button pressed for longer than 5 seconds and switch terminal R on.

Test no. 7 can be used to display the current value (sensor value) of the outside temperature in the display area within the tachometer.

Below the gear display
In addition to the time, the outside temperature is normally displayed in this display area with a display resolution of 0.5 degrees C.

If the outside temperature falls below +3 degrees C, an acoustic warning is issued.

If required, these displays are overwritten by Check Control warning symbols (e.g. the symbol for outside temperature). Check Control messages are usually announced by a gong.

Onboard computer
The outside temperature can be controlled as an additional function via the onboard computer. The outside temperature is displayed in the LCD display field below the gear display, unless it has been overwritten by a variable indicator lamp of the Check Control.