Part 2
Exterior Lighting
Common Headlamp Features
Turn Signal Indicator Lamp
The turn signal indicator lamp is incorporated into the outer part of the headlamp assembly. The lamp is located above the side lamp on halogen headlamps and the static bending/cornering lamp on Xenon headlamps. The turn signal indicator lamp uses an PH24W orange colored bulb module. The module is fitted into a holder which is connected via contacts on the headlamp housing to the main connector in the headlamp housing. The module is a snap fit in the holder and needs to be pulled sharply to remove. The holder is fitted with a seal and is located into an aperture in the headlamp housing and rotated to lock into position. Access to the holder requires removal of the headlamp from the front carrier assembly and removal of the outer locking plate from the headlamp.
The turn signal indicator 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 in ignition mode 6, the hazard flasher switch is active at all times. When active, the turn signal indicator lamps will flash at a frequency cycle of 400ms on and 400ms off.
If a bulb fails, the remaining turn signal indicator lamps bulbs continue to flash at normal speed. The turn signal indicators in the instrument cluster will flash at double speed to indicate the failure to the driver.
Side Lamp - Halogen Headlamps
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 uses a capless W5W 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 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 dependant 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.
Side Lamp - Xenon Headlamps
The side lamps on all Xenon headlamps are LED's. The 10 LED's are arranged around the outer part of the halogen fill-in lamp and the xenon projector module.
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 dependant 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 - Xenon (non-AFS headlamps only)
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 degrees 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 in ignition power mode 6. The cornering lamps are supplied power via the ignition circuit 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.
Cornering/Static Bending Lamps (Xenon AFS headlamps only)
NOTE:
The cornering/static bending lamps are not fitted to NAS market vehicles
The cornering/static bending lamps are a standard feature on AFS headlamps 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 degrees to the vehicle axis. The static bending lamps are powered by the CJB and controlled by the AFS control module. The cornering lamp functionality is controlled by the CJB as described for non-AFS headlamps.
The cornering lamp and static bending lamp is incorporated into the outer part of the headlamp assembly.
The cornering/static bending lamp uses a 35W Halogen H8 bulb which locates in a holder which is connected via wires to the main connector 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.
AFS Control
On headlamps with AFS, the cornering lamp function is as described previously for the Xenon non-AFS headlamps.
The static bending lamps operate with a steering angle sensor signal which is received by the AFS control module. The AFS control module sends a static bending lamp on request to the CJB which activates the static bending lamp bulb.
The static bending lamp operation is variable with the speed of the vehicle and the steering wheel angle. The static bending lamps illuminate at 0 mph (0 km/h) when the steering wheel rotation reaches 20 degrees. At 43 mph (70 km/h) the static bending lamps will illuminate when the steering wheel angle reaches 10 degrees. The static bending lamps will be switched off when the vehicle speed exceeds 43 mph (70 km/h).
The operation of the static bending lamps is controlled by the AFS control module. When the operation parameters of the lamp are reached, the CJB fades the static bending lamp bulb on using a PWM voltage over a period of approximately 2 seconds. When the lamp is switched off, the CJB fades the bulb off by decreasing the PWM voltage.
Halogen Headlamps
The halogen headlamps use a projector module for the low beam headlamp and a complex surface reflector for the halogen high beam lamp. 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.
The projector module comprises a reflector, the lens and the halogen bulb. The projector module only operates as a low beam halogen headlamp.
The high beam lamp reflector is divided into separate parabolic segments, with each segment having a different focal length.
The halogen headlamp uses a side lamp bulb which is located in the position used by the cornering/static bending lamp on xenon headlamps. The lens pattern for the side lamp in this position differs from the lens pattern used for the cornering/static bending lamp.
The halogen headlamps do not require adhesive decals to be applied to the clear outer lens to mask the beam cut-off when driving in opposite drive hand markets. 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 projector module. Make sure that the headlamps are off before removing the access cover.
CAUTION: This lever can be very hot if the lamps have been operating. Allow sufficient time to cool before operating the lever.
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 D3S Xenon bulb must be performed using suitable protective equipment, e.g. gloves and goggles. The glass part of the bulb must not be touched.
- 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 Bi-Xenon (the Bi-Xenon trademark is the property of Hella KGaA Hueck & Co., Germany) projector module headlamp operates as both low beam and high beam headlamp unit. The Xenon lamp (or High Intensity Discharge (HID) lamp), comprises an ellipsoidal lens with a solenoid controlled shutter to change the beam output from low to high beam. The bulb is retained with a locking ring which must be rotated to facilitate removal of the D3S bulb.
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
- Mercury free.
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 35W D3S 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 rotating a locking ring on the projector module to lock. The bulb has a pin connector which is a push to lock fitting.
The shutter controller is a solenoid which operates the shutter via a lever mechanism. 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 projector module. 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 stabilizes 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.