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Dipped beam, xenon

Dipped beam, xenon


Dipped beam is on when the light switch (10) is in position 2 and the ignition is in OFF, ON or START position. When the ignition is ON, the power supply will be applied to the dipped beam lamps by DICE. Dipped beam is used on certain markets as daylight driving lights (light switch in 0 or 1). On some markets there are also side marker lights (234FL/FR). This is an extra filament in the front direction indicators that sends a beam of light to the side through an aperture in the reflector.

To enable DICE to determine what position (0-1-2) the light switch (10) is set to, the control module uses bus information from TWICE and its own pins 39 and 15.

TWICE monitors the parking lights and sends information on the bus (Rear light Left ON/OFF and Rear light Right ON/OFF). The ON message corresponds to switch position 1 and the OFF message corresponds to position 0 or 2.

To enable DICE to determine the position setting, it uses pins 39 and 15. DICE pin 39 is connected to light switch pin 10, which corresponds to position 0. DICE pin 15 is connected to light switch pin 11, which corresponds to position 2.

+X voltage from the ignition switch is fed from pin 11 on the light switch (10) to pin 15 on the control module, whereby the dipped beam relay will be grounded via pin 4 on the control module and the relay will close. +30 voltage is fed through the dipped beam relay via fuse 11 to pin 3 on the left-hand headlamp (663FL) and via fuse 13 to pin 3 on the right-hand headlamp (663FL).

Limp-home




The limp-home function is a safety circuit in the lighting system which ensures that dipped beam can always be switched on even if DICE should be put out of action.

With the light switch in position 2, +X voltage can also be used to supply the dipped beam lamps. +X voltage is fed to the dipped beam relay, which is then in closed position, and the voltage is fed directly through the relay and fuses (11 and 13) to the dipped beam lamps.

Important

When changing a bulb, select a new bulb of the correct rating to prevent the components being damaged.


Diagnosis

Diagnostic trouble code 1160 is generated in the event of an open circuit or a short circuit to ground or a short circuit to B+.

DTCs are not generated if the voltage is below 11 V or during diagnostic communication.

Follow me home


This function activates the dipped beam when the car key is taken out of the ignition switch, the driver's door is opened and the dipswitch is moved to its rearmost position “flash”. If the driver's door is closed at any time within the next 30 seconds the dipped beam comes on for a preprogrammed duration.

“Follow me home” means that the car's dipped beam is used when there are no other light sources available. The car's dipped beam will stay on for a certain time after the car key has been removed from the ignition and the driver's door has been closed. This time period can be adjusted in DICE (20-50 seconds).

A number of conditions must be fulfilled before DICE will activate this function.

DICE uses pin 7 to detect that the key has been withdrawn from the ignition switch. DICE then needs to get a message from TWICE concerning the status of the driver's door (OPEN). When the dipswitch (215) is activated, power is supplied to pin 41 on DICE.

The last precondition is fulfilled when TWICE puts a message on the bus concerning the status of the driver's door (CLOSED). The dipped-beam relay is thereupon grounded via pin 4 on DICE for a pre-set time (20-50 seconds), causing the dipped-beam lamps to light up.

Important

When changing a bulb, select a new bulb of the correct rating to prevent the components being damaged.


Diagnosis


Diagnostic trouble code 1160 is generated in the event of an open circuit or a short circuit to ground or a short circuit to B+.

DTCs are not generated if the voltage is below 11 V or during diagnostic communication.