Operation CHARM: Car repair manuals for everyone.

Operation and Function

The Multi-function indicator is an integral part of the instrument cluster and consists of an electronic processor unit and a digital display unit. Electrical signals from external components (sensors and control modules) are fed into the electronic unit, processed and stored. The results can be shown as figures in the display. The Mode Select Switch (E 86) and the Memory Switch (E 109) are located in the wiper switch lever.

The following signals are processed by the Multi-function indicator

- Pulse from Speedometer Vehicle Speed Sensor (VSS) (G 22)
- Resistance change from Oil Temperature Sensor (G 8)
- Resistance change from Outside Air Temperature Sensor (G 17)
- Fuel consumption signal from engine control module
- Pulse from terminal TD/terminal 1

When the ignition is off, the MFA display shows time. When ignition is switched on, the time remains in the display until the Multi-function Indicator Mode Select Switch (E 86) is pressed. When the Mode Select Switch (E 86) has been operated, the selected MFA function and the stored data appear. If the Mode Select Switch (E 86) is pressed briefly and repeatedly, different functions appear one after the other.

Sequence of functions:
- Time (in hours and minutes)
- Driving time (max. 100 hours)
- Average fuel consumption (liters/100 km or miles/gallon) At speeds below 8 km/hr or 8 mph the average consumption display switches to liters/hour or gallons/hour.
- Distance driven (max. 10,000 km or 10,000 miles)
- Average speed (in km/h or mph)
- Engine oil temperature (in degrees Celsius or Fahrenheit) At temperatures below 122 ~F (50~C) dashes appear.
- Outside (ambient) temperature (in degrees Celsius or Fahrenheit)

When ignition is on, the sensor values for driving time, distance driven and fuel consumption are recorded continuously and stored. The calculation of the average speed and the average fuel consumption only takes place when the function is called up.