Operation CHARM: Car repair manuals for everyone.
Hosted by mcallihan.com
Home >> Jaguar >> 2012 >> XJ (X351) V8-5.0L >> Repair and Diagnosis >> Lighting and Horns >> Description and Operation >> Exterior Lighting >> Description >> Part 2

Part 2





Exterior Lighting

LIGHTING CONTROL SWITCH









The lighting control switch is located on the LH (left-hand) steering column multifunction switch. The lighting control switch is a rotary control with positions for the following lighting functions:
- Off
- Side lamps
- Headlamps
- AUTO headlamps
- Headlamp timer (3 time period selections).
The LH (left-hand) steering column multifunction switch also provides for the following functions:
- Low beam headlamps
- High beam headlamps
- Headlamp flash
- LH (left-hand) and RH (right-hand) turn signal indicators
- Trip computer function button. For additional information, refer to Information and Message Center Description
The switch has a turn signal indicator lane change function which is configurable by the dealer. If the switch is gently pushed to either turn signal indicator position and then released, the applicable turn signal indicators will flash 3 times and then will be automatically cancelled. If a turn signal indicator fails, the green turn signal warning indicator in the instrument cluster will flash at twice the normal rate and the audible ticking from the instrument cluster sounder will also be at twice the normal rate.

AUXILIARY LIGHTING SWITCH

NOTE:
LHD (left-hand drive) switch shown









The auxiliary lighting switch is located in the instrument panel, adjacent to the steering column. The switch has a rear fog lamp switch and a rotary thumbwheel dimmer to adjust instrument panel illumination. The auxiliary lighting switch also has a luggage compartment release switch.
The rear fog lamp switch is a non-latching switch which provides a momentary signal to the instrument cluster. The fog lamps can only be activated if the ignition is in power mode 6 and the headlamps or auto headlamps are selected on. If the fog lamp switch is pressed when the fog lamps are operating, they will be switched off. If the lighting control switch is moved to the side lamp or off position or if the auto headlamps turns off the headlamps the rear fog lamps will be extinguished. If the headlamps are subsequently turned on the rear fog lamp operation will not be active and the rear fog lamp switch must be pressed to activate the lamps.

HEADLAMP ASSEMBLY
Two types of headlamp are available; xenon without Adaptive Front lighting System (AFS) or xenon with AFS. The headlamp is secured in the front of the vehicle with three bolts; 1 inboard bolt is screwed into the front upper cross member and 2 bolts located at the rear of the headlamp assembly and secure the headlamp to a fender support brackets which in turn is connected to the upper cross-member. Xenon bulb replacement requires the removal of the 3 bolts and the headlamp assembly.
The rear of the headlamp has an access panel which is secured with four screws. The panel allows access to the xenon bulb for replacement. A smaller rubber pull-off cover on the panel can be removed to access the tourist lever. Access to the panel and the pull-off cover is by partial removal of the wheel arch splash shield.
The headlamps have 2 adjustment screws on the rear which allow for the manual setting of the vertical and horizontal alignment.
On NAS vehicles, the headlamp is regarded as 'Visual Optically Left' aiming. The adjustment screws must be turned equal amounts to maintain the correlation in the vertical axis only. There is no horizontal adjustment. Refer to the Service Repair Procedures manual for headlamp alignment data and procedures.
Each headlamp has an integral 16 pin connector which provides inputs and outputs for the various functions of the headlamp assembly.









Bi-Xenon Headlamp
The bi-xenon headlamp uses a projector module. The projector module comprises an ellipsoidal lens and a reflector. The projector reflector collects the light produced by the xenon bulb and projects the light into a focal plane containing a shield. The contour of the shield is projected onto the road by the lens.
A tourist lever mechanism is located on the right hand side of the projector module. This mechanism moves a flap 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 partial removal of the wheel arch splash shield and 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.

NOTE:
The tourist lever is not fitted to NAS vehicles.

WARNING: The Xenon system generates up to 30000 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 adhered to when working on the xenon low beam 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; for example 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 bulb in a mounted condition in the projector module installed in the headlamp.
The xenon headlamp is known as 'bi-xenon' because it operates as both a low and high beam headlamp unit. The xenon lamp, or High Intensity Discharge (HID) lamp as they are sometimes referred to, comprises an ellipsoidal lens with a solenoid controlled shutter to change the beam output from low to high beam.
The xenon headlamp system is controlled by the CJB (central junction box) 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 bulbs through their start-up phases of operation.
The xenon headlamp is a self contained unit located within the headlamp assembly. The unit comprises a reflector, the lens, a shutter controller and the xenon bulb, which together form an assembly known as the projector module. The reflector is curved and provides the mounting point for the xenon bulb. The bulb locates in a keyway to ensure the correct alignment in the reflector and is secured by a plastic mounting ring. The bulb is an integral component of the igniter and is electrically connected by a connector located in the igniter unit.
The shutter controller is a solenoid which operates the shutter mechanism via a lever. The shutter is used to change the beam projection from low beam to high beam and vice versa.
The xenon bulbs illuminate when an arc of electrical current is established between 2 electrodes within the bulb. The xenon gas sealed in the bulb reacts to the electrical excitation and the heat generated by the current flow to produce the characteristic blue/white light.
To operate at full efficiency, the xenon bulb goes through 3 full stages of operation before full output for continuous operation is achieved. The 3 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 up to 30000 volts to establish the arc. This is produced by the igniter. The warm-up phase begins once the arc is established. The xenon control module regulates the supply to the bulb 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 module changes to continuous phase. The supply voltage to the bulb is reduced and the operating power required for continual operation is reduced to 35W. The process from start-up to continuous phase is completed in a very short time.
The xenon control modules (one per headlamp) receive an operating voltage from the CJB (central junction box) 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 the regulated power supply from the control modules.
Static Bending/Cornering Lamps
The static bending/cornering lamps, which are a standard feature on AFS headlamps, are designed to illuminate the direction of travel when cornering at low speeds. The static bending/cornering lamp functionality, which is controlled by the CJB (central junction box), is unique to vehicles with AFS headlamps and operates using inputs from the steering angle sensor.
The static bending/cornering lamp LED (light emitting diode)'s are incorporated into the outer part of the headlamp assembly. The design of the lens projects a spread of light from the vehicle at approximately 45 degrees to the vehicle axis.
The static bending/cornering lamp uses 2 high power LED's located in the headlamp housing. The LED's are not serviceable components.
Cornering Lamp Functionality
The cornering lamps are 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 lamps are controlled by the LH (left-hand)steering column multifunction switch with the lighting control switch in the headlamp position and the ignition switch in power mode 6 (ignition on). The cornering lamps are supplied power with power mode 6 (ignition on) 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) at which point the static bending lamp functionality is activated.
Only one cornering lamp will illuminate at any one time. If the LH (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.
Static Bending Lamp Functionality

NOTE:
Static bending lamps only operate when the transmission is in DRIVE or in SPORT.
The static bending lamps operate with a steering angle sensor CAN (controller area network) signal and vehicle speed signal which is received by the AFS control module and the CJB (central junction box). The AFS control module sends a static bending lamp on request to the CJB (central junction box) which activates the static bending lamp LED (light emitting diode)'s
When the operation parameters of the lamp are reached, the CJB (central junction box) illuminates the static bending lamp LED (light emitting diode)'s on using a full power PWM (pulse width modulation) voltage. When the lamp is switched off, the CJB (central junction box) fades the LED (light emitting diode)'s off by decreasing the PWM (pulse width modulation) voltage in a linear manner.
Turn Signal Indicators
The turn signal indicator lamp is located in-board of the headlamp projector module. The indicator lamp comprises 8 amber LED (light emitting diode)'s arranged in a circular pattern.
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 lamps bulbs continue to flash at normal speed.
Side Lamps
The side lamp is located in a row along the bottom of the headlamp. The side lamp comprises 8 LED (light emitting diode)'s.
The side lamps are operated by selecting side lamps or headlamps on the lighting control switch. The side lamps are functional at all times and are dependant on a particular ignition mode status. 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 (central junction box) from the rain/light sensor.
Side Marker Lamps (NAS only)
The side marker lamp is located at the outboard end of the side lamps and is illuminated by a single amber LED (light emitting diode). An amber reflex reflector continues from the end of the side marker lamp and forms a triangle around the static bending/corning lamp (where fitted).
The side marker lamp is active at all times when the side lamps are active.

ADAPTIVE FRONT LIGHTING SYSTEM (AFS) HEADLAMPS
The AFS headlamp is similar in its construction to the xenon headlamp. The projector module is constructed and operates as described for the xenon headlamp with the addition of the AFS system which allows the projector module to be moved vertically and horizontally by stepper motors. The following description covers the additional differences to the xenon headlamp with AFS.
The AFS is a system to improve driver visibility under differing driving conditions. AFS provides a larger visible area which is illuminated when cornering by adjusting the position of the beam distribution on the road. Horizontal adjustment is made automatically to the most suitable orientation for the driving conditions using steering angle and information from other vehicle sensors.
AFS includes the dynamic headlamp leveling system described in the 'Headlamp Leveling' section of this document. The bi-xenon module within the headlamp is controlled by actuator motors which rotate the projector module on its vertical and horizontal axes to adjust the beam output to suit the cornering conditions and vehicle inclination. Only the adaptive bi-xenon lamp projector module swivels, all other lamps remain static.
The AFS is controlled by an AFS control module which is located on the instrument panel frame, behind the glove compartment. The module is connected to and controls an AFS power module located inside the headlamp housing. Signals from the AFS control module are processed by the AFS power module which powers stepper motors to adjust the vertical and horizontal alignment of the projector module. The AFS power module also controls and regulates the operation of the static bending lamp (if fitted) which is requested by the AFS control module but controlled by the CJB (central junction box).


pro multis · About Operation CHARM