Operation CHARM: Car repair manuals for everyone.

GF54.30-P-2007Q Instrument Cluster Illumination, Function



GF54.30-P-2007Q Instrument Cluster Illumination, Function

Activating the instrument cluster illumination
The instrument cluster (A1) illumination is switched on automatically when the instrument cluster is activated. The details on the instrument cluster (A1) can only be seen clearly once the instrument cluster has been activated because of the "black screen technology".
The instrument cluster (A1) is activated when the following events occur:
^ CAN message standing lamp ON
^ Circuit 15R ON
^ Trip odometer reset button (A1s3) operated
^ Driver's door opened.
^ Driver's door closed.

The brightness of the illumination depends on:
^ the CAN message from the rain/light sensor (B38/2)
^ the status of "circuit 58d" (standing lamp information)
^ the position of the instrument lighting rheostat and reset button (A1r1)

Regulation of the display illumination
With the CAN message "standing lamp ON" the current position of the instrument lighting rheostat and reset button (A1r1) is transferred over the interior CAN.
In this state, the signal from the rain/light sensor (B38/2) via the overhead control panel control unit (N70) is disregarded.

Regulation of the display illumination via sensors
When the CAN message "standing lamp OFF" is received, circuit 58d is set to 0%. Because of this, the CAN message from the rain/ light sensor (B38/2) via the overhead control panel control unit (N70) is processed as a control variable and converted.

The display brightness via the rain/light sensor (B38/2) is only dependent on the ambient brightness.
If a fault occurs with the rain/light sensor (B38/2), the overhead control panel control unit (N70) sets circuit 58d to 100%. The display illumination can then be adjusted using the instrument lighting rheostat and reset button (A1r1).