2008 INFINITI QX56 high beam

EXL-2
HEADLAMP (HI) CIRCUIT ................................28
Description ........................................................... ...28
Component Function Check ...................................28
Diagnosis Procedure ..............................................28
HEADLAMP (LO) CIRCUIT ...............................30
Description ........................................................... ...30
Component Function Check ...................................30
Diagnosis Procedure ..............................................30
FRONT FOG LAMP CIRCUIT ...........................32
Description ........................................................... ...32
Component Function Check ...................................32
Diagnosis Procedure ..............................................32
PARKING LAMP CIRCUIT ................................34
Description ........................................................... ...34
Component Function Check ...................................34
Diagnosis Procedure ..............................................34
TURN SIGNAL LAMP CIRCUIT ........................37
Description ........................................................... ...37
Component Function Check ...................................37
Diagnosis Procedure ..............................................37
OPTICAL SENSOR ...........................................40
Description ..............................................................40
Component Function Check ...................................40
Diagnosis Procedure ..............................................40
HEADLAMP AIMING SWITCH ..........................42
Description ........................................................... ...42
Diagnosis Procedure ..............................................42
HEADLAMP .......................................................43
Wiring Diagram .................................................... ...43
DAYTIME LIGHT SYSTEM ................................47
Wiring Diagram .................................................... ...47
AUTO LIGHT SYSTEM ......................................54
Wiring Diagram .................................................... ...54
HEADLAMP AIMING SYSTEM (MANUAL) ......61
Wiring Diagram .................................................... ...61
FRONT FOG LAMP SYSTEM ...........................65
Wiring Diagram .................................................... ...65
TURN SIGNAL AND HAZARD WARNING
LAMP SYSTEM .............................................. ...
68
Wiring Diagram .................................................... ...68
PARKING, LICENSE PLATE AND TAIL
LAMPS SYSTEM ............................................ ...
75
Wiring Diagram .................................................... ...75
STOP LAMP ......................................................81
Wiring Diagram .................................................... ...81
BACK-UP LAMP ................................................85
Wiring Diagram .................................................... ...85
TRAILER TOW ..................................................90
Wiring Diagram .................................................... ...90
ECU DIAGNOSIS .......................................99
BCM (BODY CONTROL MODULE) ............... ...99
Description ........................................................... ...99
IPDM E/R (INTELLIGENT POWER DISTRI-
BUTION MODULE ENGINE ROOM) ................
100
Description ........................................................... .100
SYMPTOM DIAGNOSIS ...........................101
EXTERIOR LIGHTING SYSTEM SYMPTOMS ..101
Symptom Table .................................................... .101
NORMAL OPERATING CONDITION ...............103
Description ........................................................... .103
BOTH SIDE HEADLAMPS DO NOT SWITCH
TO HIGH BEAM ................................................
104
Description ........................................................... .104
Diagnosis Procedure .............................................104
BOTH SIDE HEADLAMPS (LO) ARE NOT
TURNED ON .....................................................
105
Description ............................................................105
Diagnosis Procedure .............................................105
PARKING, LICENSE PLATE AND TAIL
LAMPS ARE NOT TURNED ON ......................
106
Description ........................................................... .106
Diagnosis Procedure .............................................106
BOTH SIDE FRONT FOG LAMPS ARE NOT
TURNED ON .....................................................
107
Description ............................................................107
Diagnosis Procedure .............................................107
PRECAUTION ...........................................108
PRECAUTIONS .............................................. ..108
Precaution for Supplemental Restraint System
(SRS) "AIR BAG" and "SEAT BELT PRE-TEN-
SIONER" .............................................................. .
108
Precaution Necessary for Steering Wheel Rota-
tion After Battery Disconnect ................................
108
ON-VEHICLE REPAIR ..............................110
ADJUSTMENT AND INSPECTION ................ ..110
HEADLAMP ............................................................ .110
HEADLAMP : Aiming Adjustment .........................110
FRONT FOG LAMP ................................................ .111
FRONT FOG LAMP : Aiming Adjustment .............111
REMOVAL AND INSTALLATION .............113
HEADLAMP .................................................... ..113
Revision: March 2010 2008 QX56

HEADLAMPEXL-7
< FUNCTION DIAGNOSIS >
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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
< FUNCTION DIAGNOSIS >
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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
ALLIA0380ZZ
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

EXL-12
< FUNCTION DIAGNOSIS >
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-24
< FUNCTION DIAGNOSIS >
DIAGNOSIS SYSTEM (BCM)
1: The item is indicated, not monitored
ACTIVE TEST
Monitor item[Unit] Description
IGN ON SW
[ON/OFF] The switch status input from ignition switch
ACC ON SW
[ON/OFF] The switch status input from ignition switch
TURN SIGNAL R
[ON/OFF]
Each switch status that BCM judges from the combination switch reading function
TURN SIGNAL L
[ON/OFF]
HI BEAM SW
[ON/OFF]
HEAD LAMP SW1
[ON/OFF]
HEAD LAMP SW2
[ON/OFF]
LIGHT SW 1ST
[ON/OFF]
AUTO LIGHT SW
[ON/OFF]
PASSING SW
[ON/OFF]
FR FOG SW
[ON/OFF]
CARGO LAMP SW
[ON/OFF]
RR FOG SW
1
[ON/OFF]
—
DOOR SW-DR
[ON/OFF] The switch status input from front door switch LH
DOOR SW-AS
[ON/OFF] The switch status input from front door switch RH
DOOR SW-RR
[ON/OFF] The switch status input from rear door switch RH
DOOR SW- RL
[ON/OFF] The switch status input from rear door switch LH
DOOR SW-BK
[ON/OFF] The switch status input from the back door switch
OPTICAL SENSOR
[V] The value of exterior brightness voltage input from the optical sensor
Test item
Operation Description
TA I L L A M P ON
Transmits the position light request signal to IPDM E/R via CAN commu-
nication to turn the tail lamp ON.
OFF Stops the tail lamp request signal transmission.
HEAD LAMP HI
Transmits the high beam request signal via CAN communication to turn
the headlamp (HI)
LO Transmits the low beam request signal via CAN communication to turn
the headlamp (LO).
OFF Stops the high & low beam request signal transmission.
Revision: March 2010 2008 QX56

EXL-26
< FUNCTION DIAGNOSIS >
DIAGNOSIS SYSTEM (IPDM E/R)
DIAGNOSIS SYSTEM (IPDM E/R)
CONSULT - III Function (IPDM E/R)INFOID:0000000001547122
APPLICATION ITEM
CONSULT-III performs the following functi ons via CAN communication with IPDM E/R.
DATA MONITOR
Monitor item
ACTIVE TEST
Te s t i t e m
Diagnosis mode Description
Self Diagnostic Result Displays the diagnosis results judged by IPDM E/R.
Data Monitor Displays the real-time input/output data from IPDM E/R input/output data.
Active Test IPDM E/R can provide a drive signal to electronic components to check their operations.
CAN Diag Support Monitor The results of transmit/receive diagnosis of CAN communication can be read.
Monitor Item
[Unit] MAIN SIG-
NALS Description
TAIL & CLR REQ
[Off/On] ×Displays the status of the tail and clearance lamp request signal received from
BCM via CAN communication.
HL LO REQ
[Off/On] ×
Displays the status of the low beam request signal received from BCM via CAN
communication.
HL HI REQ
[Off/On] ×
Displays the status of the high beam request signal received from BCM via CAN
communication.
FR FOG REQ
[Off/On] ×Displays the status of the front fog light request signal received from BCM via
CAN communication.
IGN RLY
[Off/On] ×
Displays the status of the ignition relay judged by the IPDM E/R-.
DTRL REQ
[Off] ×
Displays the status of the daytime light request signal received from the BCM via
CAN communication.
Test item
Operation Description
EXTERNAL LAMPS Off
OFF
TAIL Operates the tail lamp relay.
Lo Operates the headlamp low relay.
Hi Operates the headlamp low relay and ON/OFF the headlamp high relay at 1 sec-
ond intervals.
Fog Operates the front fog lamp relay.
Revision: March 2010 2008 QX56