General Information

The following buttons and displays are included:

• Vehicle electrical system control module -J519-
• Photo transistor inside the instrument cluster control module -J285-
• Instrument panel and switch illumination dimmer switch -E20- in the headlamp switch -E1-

The buttons on the symbols and the displays are illuminated to make it easier for the vehicle occupants to see them. The illumination for some switches is dependant on the outside light (terminal 58s), some are dependant on the outside light and the ignition (terminal 58st) and the display illumination (terminal 58d).

The vehicle electrical system control module -J519- controls the button and display illumination and is call the dimming master. The dim master calculates the dimming values for terminals 58s, 58st and 58d based on the outside brightness and the intensity set by the driver.

The instrument cluster control module -J285- determines the ambient brightness. The instrument cluster has a photo transistor that senses the brightness. The instrument cluster control module -J285- filters the value and then sends it to the vehicle electrical system control module -J519- via the CAN Bus.

The driver uses the instrument panel and switch illumination dimmer switch -E20-, which is integrated in the headlamp switch -E1-, to set the brightness intensity. The setting is sent to the vehicle electrical system control module -J519- via the LIN Bus.

The dimming values are independent of each other and have different values.

The dimming values, terminal 58s and terminal 58st are emitted by the vehicle electrical system control module -J519- both as discrete PWM signals and as Bus signals. The terminal 58d dimming value is emitted as a Bus signal.