2008 INFINITI QX56 headlamp

HEADLAMPEXL-7
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FUNCTION DIAGNOSIS
HEADLAMP
System DiagramINFOID:0000000001547094
System DescriptionINFOID:0000000001547095
Control of the headlamp system operation is dependent upon the position of the lighting switch (combination
switch). When the lighting switch is placed in the 2nd position, the BCM (body control module) receives input
requesting the headlamps and park lamps to illuminate. Th is input is communicated to the IPDM E/R (intelli-
gent power distribution module engine room) via the CA N communication lines. The CPU (central processing
unit) of the IPDM E/R controls the headlamp high and headl amp low relay coils. When energized, these relays
direct power to the respective headlamps, which then illuminate.
Component Parts LocationINFOID:0000000001547096
Component DescriptionINFOID:0000000001547097
XENON HEADLAMP
A Xenon type headlamp is adapted to the low beam headlamps. Xenon bulbs do not use a filament.
Instead,they produce light when a high voltage current is passed between two tungsten electrodes through a
AWLIA0009GB
1. BCM M18, M20 (view with instrument
panel removed) 2. IPDM E/R E122, E123, E124 3. Combination switch M28
4. Combination meter M23, M24
ALLIA0379ZZ
Revision: March 2010 2008 QX56

EXL-8
< FUNCTION DIAGNOSIS >
HEADLAMP
mixtureof xenon (an inert gas) and certain other metal halides. In addition to added lighting power, electronic
controlof the power supply gives the headlamps stable quality and tone color.Following are some of the many
advantages of the xenon type headlamp.
• The light produced by the headlamps is a white color comparable to sunlight that is easy on the eyes.
• Light output is nearly double that of halogen headlamps, affording increased area of illumination.
• The light features a high relative spectral distribution at wavelengths to which the human eye is most sensi-tive. This means that even in the rain, more light is reflected back from the road surface toward the vehi-
cle,for added visibility.
• Power consumption is approximately 25 percent less than halogen headlamps, reducing battery load..
HIGH BEAM OPERATION/FLASH-TO-PASS OPERATION
With the lighting switch in the 2ND position and placed in HIGH position, the BCM receives input requesting
the headlamp high beams to illuminate. The flash to pass feature can be used any time and also sends a sig-
nal to the BCM. This input is communicated to t he IPDM E/R via the CAN communication lines. The CPU of
the combination meter controls the ON/OFF status off the HIGH BEAM indicator. The CPU of the IPDM E/R
controls the headlamp high relay coil which supplies power to the high beam headlamps.
The combination meter receives a high beam request signal (ON) via the CAN communication lines and turns
the high beam indicator lamp ON.
COMBINATION SWITCH READING FUNCTION
Refer to BCS-7, "System Description".
AUTO LIGHT OPERATION
Refer to EXL-11, "System Description".
Revision: March 2010 2008 QX56

DAYTIME LIGHT SYSTEMEXL-9
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DAYTIME LIGHT SYSTEM
System DiagramINFOID:0000000001547098
System DescriptionINFOID:0000000001547099
The headlamp system for Canada vehicles is equipped with a daytime light control unit that activates the high
beam headlamps at approximately half illumination whenever the engine is operating. If the parking brake is
applied before the engine is started the daytime lights will not be illuminated. The daytime lights will illuminate
once the parking brake is released. Thereafter, the daytime lights will continue to operate when the parking
brake is applied.
Component Parts LocationINFOID:0000000001547100
AWLIA0010GB
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Revision: March 2010 2008 QX56

EXL-10
< FUNCTION DIAGNOSIS >
DAYTIME LIGHT SYSTEM
Component Description
INFOID:0000000001547101
After starting the engine with the parking brake released and the lighting switch in the OFF or 1ST position, the
headlamp high beam automatically turns on at a reduced intensity. With the lighting switch in the 2nd position
or with autolamps ON, the headlamps function the same as conventional light systems.
OPERATION
The BCM monitors inputs from the parking brake switch and the combination switch to determine when to acti-
vate the daytime light system. The BCM sends a dayti me light request to the IPDM E/R via the CAN commu-
nication lines. The IPDM E/R grounds the daytime light relay which in turn, provides power to the ground side
of the LH high beam lamp. Power flows backward through the LH high beam lamp to the IPDM E/R, through
the high beam fuses, through the RH high beam lamp circuit to the RH high beam lamp and on to ground. The
high beam lamps are wired in series which causes them to illuminate at a reduced intensity.
1. IPDM E/R E119, E122, E123, E124 2. Parking brake switch M11 3. BCM M18, M20 (view with instrument
panel removed)
4. Daytime running light relay E103 5. Combination switch M28 6. Combination meter M24
Revision: March 2010 2008 QX56

AUTO LIGHT SYSTEMEXL-11
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AUTO LIGHT SYSTEM
System DiagramINFOID:0000000001547102
System DescriptionINFOID:0000000001547103
• BCM (Body Control Module) controls auto light operati on according to signals from optical sensor, lighting
switch and ignition switch.
• IPDM E/R (Intelligent Power Distribution Module Engine Room) operates parking, license plate, tail and
headlamps according to CAN communication signals from BCM.
• Optical sensor detects ambient br ightness and converts light (lux) to voltage, then sends the optical sensor
signal to BCM.
OUTLINE
The auto light control system has an optical sensor that detects outside brightness.
When the lighting switch is in AUTO position, it automat ically turns ON/OFF the parking, license plate, tail and
headlamps in accordance with the ambient light. Sensitivity can be adjusted in four steps. For the details of the
setting, Refer to EXL-23, "
EXTERNAL LAMP : CONSULT-III Function".
AWLIA0011GB
Revision: March 2010 2008 QX56

EXL-12
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AUTO LIGHT SYSTEM
Component Parts Location
INFOID:0000000001547104
Component DescriptionINFOID:0000000001547105
AUTO LIGHT OPERATION
The auto light system operates t he low beam and high beam headlamps, parking lamps, tail lamps and license
plate lamps. The BCM monitors the lighting switch (com bination switch) position as a part of the BCM combi-
nation switch reading function. When the lighting switch is in the AUTO position, the BCM automatically turns
the lamps ON/OFF according to ambient light brightness.
NOTE:
Timing for when lamps turn ON/OFF can be changed by the function setting of CONSULT-III. Refer to EXL-23,
"EXTERNAL LAMP : CONSULT-III Function".
COMBINATION SWITCH READING FUNCTION
Refer to BCS-7, "System Description".
1. BCM M18, M19, M20 (view with instru-
ment panel removed) 2. IPDM E/R E122, E123, E124 3. Optical sensor M302
4. Front door switch LH B8
RH B108 5. Rear door switch
LH B18
RH B116 6. Back door switch
D502
7. Combination switch M28
ALLIA0382ZZ
Revision: March 2010 2008 QX56

EXL-14
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HEADLAMP AIMING SYSTEM (MANUAL)
HEADLAMP AIMING SYSTEM (MANUAL)
System DiagramINFOID:0000000001806201
System DescriptionINFOID:0000000001806202
The headlamp aiming system (manual) controls the headlamp light axis height according to input from the
headlamp aiming switch. The variable internal resist ance of the headlamp aiming switch controls the signal
ground of the headlamp aiming motors located on the front combination lamp LH and RH.
Component DescriptionINFOID:0000000001806204
AWLIA1629GB
Part Description
Headlamp aiming motor Moves the headlamp up/down based on input from the headlamp aiming switch.
Headlamp aiming switch Controls variable ground to the headlamp aiming motor signal to move the headlamp aim-
ing motor up/down.
Revision: March 2010
2008 QX56

FRONT FOG LAMPEXL-15
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FRONT FOG LAMP
System DiagramINFOID:0000000001547106
System DescriptionINFOID:0000000001547107
The front fog lamps are activated with the lighting switch (combination switch). The lighting switch signal to
the BCM is monitored with the BCM combination switch reading function. When the fog lamps are turned ON
with the lighting switch, the BCM sends a front fog lamp request signal via CAN communication lines to the
IPDM E/R. The IPDM E/R grounds the front fog la mp relay coil to activate the front fog lamps.
Component Parts LocationINFOID:0000000001547108
Component DescriptionINFOID:0000000001547109
FRONT FOG LAMP OPERATION
When the lighting switch is in front fog lamp ON posit ion and also in 1ST or 2ND position or AUTO position
(headlamp is ON), the BCM detects FR FOG ON and t he HEAD LAMP1, 2 ON or the AUTO LIGHT ON. The
BCM sends a front fog lamp request ON signal via the CAN communication lines to the IPDM E/R. The IPDM
E/R then turns ON the front fog lamp re lay sending power to the front fog lamps.
COMBINATION SWITCH READING FUNCTION
Refer to BCS-7, "System Description".
JPLIA0004GB
1. BCM M18, M20 (view with instrument
panel removed) 2. IPDM E/R E122, E123, E124 3. Combination switch M28
ALLIA0379ZZ
Revision: March 2010
2008 QX56