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Front fog lights, detailed description

Front fog lights, detailed description

The two fog lights are located in the spoiler. They are activated with a switch (88) when the light switch (10) is in position 1 or 2 (market-dependent). This function is programmable.


The fog light switch is connected to BCM (707). BCM detects the switch position and sends the bus message "Front fog lights, button active ON", which is used by the Underhood Electrical Centre (UEC) to control the fog lights. The lamps are supplied PWM-regulated voltage.


When the fog light switch (88) is depressed, BCM pin A28 is grounded. BCM sends the bus message "Front fog lights, button active ON". UEC reads the bus message and activates the outputs, pins 33 and 10, to the fog lights (85FR/FL) if the market-dependent conditions are met. UEC sends the bus message "Front fog lights, indicator active ON", which is used by MIU (540) to light the indicator lamp when the fog lights are activated.

Variant 1, EU


• Parking lights or dipped beam on

• Ignition position ON


Variant 2, US


• Dipped beam on

• Ignition position ON


Variant 3, SE


• Parking lights or main beam on

• Ignition ON


Overvoltage protector

The power supply from UEC (342) pins 33 and 10 is regulated with PWM 65 Hz so that the voltage does not exceed 13.0 V. This reduces heat build-up in the lamp housing.


Filament monitor

In the event of a break in the front fog light circuits, UEC (342) sends the bus message "Right front fog light not working ON" or "Left front fog light not working ON".


Note

If one or more of the conditions are not met and the fog lights do not come on when the switch is depressed, the switch must be pressed again to light the fog lights once all conditions have been met.


Important

When changing a bulb, use one with the right output otherwise the components could be damaged.