Headlamp Assembly
HEADLAMP ASSEMBLY
Three types of headlamp are available; Halogen, Bi-Xenon or Adaptive Front lighting System (AFS). The headlamps share a common, clear lens.
The headlamps are located behind the front carrier assembly. Each headlamp is secured to the front carrier assembly with two locking plates. The locking plate slides in grooves in the rear of the headlamp and two holes in each plate locate on pins on the carrier. Each locking plate is pressed down to lock the pins in the locking plate holes. The locking plates allow removal of the headlamp from the carrier for bulb changing without the requirement for special tools.
The rear of the headlamp unit has removable access panels which allow access to the bulbs for replacement. A large cover, which is rotated anti-clockwise to remove, allows access to the low/high beam bulb on both halogen and xenon
headlamps. Another removable cover provides access to the high beam only halogen bulb which is retained with a spring clip. A smaller cover can also be rotated anti-clockwise to provide access to the turn signal lamp bulb. Below this cover is a removable cover which provides access to the side lamp bulb, the cornering lamp/static bending lamp bulb and the side marker lamp bulb on NAS models.
The headlamps have two adjustment screws on the rear which allow for the manual setting of the vertical and horizontal alignment. Refer to the Service Repair Procedures information for headlamp alignment data.
Each headlamp has an integral sixteen pin connector which provides inputs and outputs for the various functions of the headlamp assembly. The usage of the pins differs between model variants, refer to the Electrical Reference Library (ERL) for pin details.
The low beam headlamps are switched on when the ignition switch is in the ignition position (II) and:
^ the lighting control switch is in the headlamp position
^ the lighting control switch is in the AUTO position and a 'lights on' signal is received by the CJB from the rain/light sensor.
The low beam headlamps can also be operated by the headlamp delay feature.
The high beam headlamps are switched on when the ignition switch is in the ignition position (II) and:
^ the low beam headlamps are selected on in the headlamp position or activated via the AUTO feature
^ The left hand steering column multifunction switch is pushed forward away from the driver.
The high beam headlamps will be switched off when:
^ The left hand steering column multifunction switch is moved rearward towards the driver
^ The low beam headlamps are switched off
^ The ignition switch is moved to the auxiliary position (I) or off position (0).
Halogen Headlamps
The halogen headlamps use a complex surface reflector for both the low beam lamp and the halogen fill in high beam lamp. This type of reflector has the reflector divided into separate parabolic segments, with each segment having a different focal length. The halogen headlamps require adhesive decals to be applied to the clear outer lens to mask the beam cut-off when driving in opposite drive hand markets.
The low and high beam bulbs are quartz halogen H7, with a rating of 55W. The bulbs are retained in the headlamp unit with conventional wire retaining clips.
Xenon Headlamps
Safety Precautions
WARNING: The Xenon system generates up to 28000 volts and contact with this voltage could lead to fatality. Make sure that the headlamps are switched off before working on the system.
The following safety precautions must be followed when working on the xenon headlamp system:
^ DO NOT attempt any procedures on the xenon headlamps when the lights are switched on.
^ Handling of the D2S Xenon bulb must be performed using suitable protective equipment, e.g. gloves and goggles. The glass part of the bulb must not be touched.
^ Xenon bulbs must be disposed of as hazardous waste.
^ Only operate the lamp in a mounted condition in the reflector.
The xenon headlamps use a complex surface reflector for the Halogen fill in high beam lamp only lighting unit, which is of the same design as the high beam unit used on the Halogen headlamps. This type of reflector has the
reflector divided into separate parabolic segments, with each segment having a different focal length.
The high beam bulbs are quartz halogen H7, with a rating of 55W. The bulbs are retained in the headlamp unit with conventional wire retaining clips.
The xenon headlamp is known as bi-xenon and operates as both low beam and high beam headlamp unit. The xenon lamp or High Intensity Discharge (HID) lamp as they are sometimes called, comprises an ellipsoidal lens with a solenoid controlled shutter to change the beam output from low to high beam.
NOTE: If the lighting control switch is in the OFF position, the xenon lamps do not operate when the high beam 'flash' function is operated. If the lighting switch is in the headlamps position or AUTO position with the low beam lamps active, the xenon low beam will remain on when the high beam 'flash' function is operated.
The xenon headlamp system is controlled by the CJB using a control module for each headlamp and an igniter. The control modules and the igniters provide the regulated power supply required to illuminate the xenon bulbs through their start-up phases of operation.
Xenon/Halogen Headlamp Beam Comparison
The xenon low/high beam headlamps use ellipsoidal technology for the lens and reflector providing improved night time visibility compared to conventional halogen headlamps. The xenon headlamps provide the following benefits when compared to halogen headlamps:
^ Longer bulb life - Approximately 3 to 5 times longer than a halogen bulb Increased light output - xenon headlamps output 3 to 4 times more light on the road surface than halogen headlamps
^ Blue/White light which is closer to natural daylight - xenon lamps produce a blue/white light compared to a yellow light produced by a halogen bulb
^ Improved night time driving visibility - xenon lamps produce a wider and brighter beam in front of the vehicle than conventional halogen bulbs
^ Lower running temperatures
^ Lower power consumption.
Xenon Headlamp Construction
The xenon headlamp is a self contained unit located within the headlamp assembly. The unit comprises a reflector, an adaptor ring, the lens, a shutter controller and the xenon bulb, which as an assembly is known as the projector module.
The reflector is curved and provides the mounting for the xenon bulb. The bulb locates in a keyway to ensure correct alignment in the reflector and is secured by pushing and turning to lock. The bulb has a two pin connector which is also a push and turn to lock fitting.
The shutter controller is a solenoid which operates, via a lever mechanism, to the shutter. The shutter is used to change the beam projection from low beam to high beam and visa versa.
A tourist lever mechanism is located on the right hand side of the projector module. This mechanism moves to blank off a portion of the beam spread to enable the vehicle to be driven in opposite drive hand markets without applying blanking decals to the headlamp lens. The beam is changed by removing the access cover at the rear of the lamp assembly and moving a small lever located near the bulb holder, at the side of the reflector. Make sure that the headlamps are off before removing the access cover.
The xenon bulbs illuminate when an arc of electrical current is established between two electrodes within the bulb. The xenon gas sealed in the bulb reacts to the electrical excitation and the heat generated by the current flow. The xenon gas reaction to the controlled current flow between the electrodes produces the blue/white light.
To operate at full efficiency, the xenon bulb goes through three stages of operation before full output for continuous operation is achieved. The three phases are; start-up phase, warm-up phase and continuous phase.
In the start-up phase, the bulb requires an initial high voltage starting pulse of 18000 to 28000 volts to establish the arc. This is produced by the igniters. The warm-up phase begins once the arc is established. The xenon control modules regulate the supply to the bulbs to 2.6A which gives a lamp output of 75W During this phase, the xenon gas begins to illuminate brightly and the environment within the bulb stabilises ensuring a continual current flow between the electrodes. When the warm-up phase is complete, the xenon control modules change to continuous phase. The supply voltage to the bulb is reduced and the operating power required for continual operation is reduced to 35W.
The xenon system is controlled by the CJB, the two xenon control modules and the two igniters. The xenon control modules (one per headlamp) receive an operating voltage from the CJB when the headlamps are switched on. The modules regulate the power supply required through the phases of start-up.
The igniters (one per headlamp) generate the initial high voltage required to establish the arc. The igniters have integral coils which generate high voltage pulses required for start-up. Once the xenon bulbs are operating, the igniters provide a closed circuit for regulated power supply from the control modules.
Turn Signal Lamp
The turn signal lamp is incorporated into the outer part of the headlamp assembly. The lamp is located above the side lamp/cornering lamp. The turn signal lamp uses an 27W/7W S8W wedge bulb. The bulb is fitted into a holder which is connected via wires to the main connector on the headlamp housing. The holder is fitted into an aperture in the headlamp housing and rotated to lock into position. The bulb is accessible via a sealed cover which is attached to the rear of the headlamp housing. The cover is secured in the housing by rotating in a clockwise direction until locked. Access to the cover requires removal of the headlamp from the front carrier assembly and removal of the outer locking plate from the headlamp.
The turn signal lamps are operated by the left hand steering column multifunction switch or by the hazard flasher switch. The steering column multifunction switch is only active with the ignition switch in the ignition position (II), the hazard flasher switch is active at all times. When active, the turn signal lamps will flash at a frequency cycle of 380ms on and 380ms off.
If a bulb fails, the remaining turn signal lamps bulbs continue to flash at normal speed. The turn signal indicators in the instrument cluster will flash at double speed to indicate the bulb failure to the driver.
Side Lamp
The side lamp is incorporated into the outer part of the headlamp assembly and is located below the turn signal indicator lamp. The side lamp shares the same housing and reflector as the cornering lamp and static bending lamp (when fitted).
The side lamp uses a capless 5W wedge fitting bulb which locates into a holder which is connected via wires to the main connector on the headlamp housing. The holder is a push fit into a receptacle in the headlamp housing. The bulb is accessible via a removable cover at the rear of the headlamp housing. Access to the cover requires removal of the headlamp from the front carrier assembly and partial removal of the outer locking plate from the headlamp.
The side lamps are operated by selecting side lamps or headlamps on the lighting control switch. The side lamps are operational at all times and are not dependent on the ignition switch position. The side lamps will also be illuminated when the lighting control switch is in the AUTO position and a 'lights on' signal is received by the CJB from the rain/light sensor.
Cornering Lamp
NOTE: The cornering lamps are not fitted to NAS market vehicles
The cornering lamps are an optional feature designed to illuminate the direction of travel when cornering at low speeds. The design of the lens projects a spread of light from the vehicle at approximately 45 ° to the vehicle axis.
The cornering lamp is incorporated into the outer part of the headlamp assembly and shares the same housing and reflector as the side lamp.
The cornering lamp uses a 35W Halogen H8 bulb which locates in a holder which is connected on the headlamp housing.
The holder is located in an aperture in the headlamp housing and rotated to lock. The bulb is accessible via a removable cover at the rear of the headlamp housing.
The cornering lamps are controlled by the left hand steering column multifunction switch with the lighting control switch in the headlamp position and the ignition switch in position II. The cornering lamps are supplied power via the ignition switch to ensure that they do not function with the headlamp delay feature. The cornering lamps are deactivated if
the vehicle speed exceeds 25 mph (40 km/h).
Only one cornering lamp will illuminate at any one time. If the left hand turn signal indicators are selected on,
the left hand cornering lamp will be illuminated and visa versa, providing the vehicle speed and lighting control switch positions are correct. Cornering lamps are disabled when reverse gear is selected.