An Overview

Main Lighting, Detailed Description

Main and dipped beam, tail lights, number plate lighting and parking lights are part of the main lighting.







Power is supplied to the headlamps from the Underhood Electrical Centre, UEC (342), which has semiconductor outputs. This makes it possible to supply PWM-regulated voltage to the lamps. The output value of the supply voltage is 13.5 V, which extends the service life of the bulb.

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

UEC handles logic for the main lighting. The light switch (10) is connected to BCM (707), which sends out bus messages about the position of the switch.

The dipswitch (215) is connected to the Column Integration Module, CIM (703). CIM sends bus messages about the position of the switch. UEC uses these bus messages to activate main or dipped beam.

The headlamp flasher, a main beam flash , can be activated regardless of the position of the ignition switch and light switch by using the dipswitch (215) to the right of the steering wheel.

Main beam is operated with the dipswitch (215) and the light switch (10). The dipswitch controls main beam 2 different ways: main beam flash (stalk pulled to spring-back position) and main beam (stalk in a fixed position). Either way, the stalk is pulled towards the steering wheel rim.

For main beam to shine continuously, the light switch (10) must be in position 2.

On certain markets, dipped beam is used as daytime running lights. This depends on how UEC is programmed.

Daytime Running Lights (DRL)
On certain markets, dipped beam is used as daytime running lights, which light automatically when the ignition is switched on.

DRL can be adjusted (ON/OFF) using the diagnostic tool. If the value is set to ON, dipped beam will come on when the light switch (10) is in position 0. If the value is set to OFF, neither parking lights nor dipped beam will come on when the light switch (10) is in position 0.







If main beam is on and the ignition is turned off, or if the light switch is turned to any other position, the main beam will be switched off and must be turned on again.

When the ignition is off, the same programming function applies to all markets. In position 0, no lights are lit. In position 1, parking lights are lit.

Halogen headlamps
Each headlamp contains an H7 halogen bulb with a 70 mm lens for dipped beam as well as an H7 bulb for main beam. The outer headlamp lens is plastic.

When dipped beam is selected, only the H7 bulb for dipped beam (12) lights. When main beam is selected, both the dipped and the main beam lamps (11) light. If the output of the bulbs exceeds 100 W, a DTC is generated in UEC and an error message is displayed in SID.

Xenon headlamps
Each headlamp (663 FL/FR) contains a 35 W Xenon bulb (D2S) with a 70 mm lens for dipped and main beam, corresponding ballast and ignition transformer. There is also an H7 halogen bulb that is used for main beam on certain markets. Xenon bulb optics shift between dipped and main beam image through a screen that drops down. The outer headlamp lens is plastic. Cars with Xenon lamps are equipped with automatic headlamp levelling.

When dipped beam is selected, only the xenon bulb for dipped beam (11a) lights. When main beam is selected, both the xenon and the main beam lamps light or the xenon lamp lights by itself, depending on the market. If the output of the halogen bulb exceeds 100 W, a DTC is generated in UEC and an error message is displayed in SID.

Xenon headlamps, US/CA
Each headlamp (663 FL/FR) contains a 35 W Xenon bulb (D2S) with a 70 mm lens for dipped beam, corresponding ballast and ignition transformer. There is also an H7 halogen bulb that is used for main beam. The outer headlamp lens is plastic. Cars with Xenon headlamps are equipped with automatic headlamp levelling.

For dipped beam, only the Xenon lamps for dipped beam shine (11a). For main beam, both the Xenon lamps and main beam bulbs (H7) are lit. If the rating of the halogen lamps exceeds 100 W, a DTC is generated in the UEC and a fault message appears on the SID.