2007 INFINITI QX56 Head light

AUTO LIGHT SYSTEM
LT-35
< SERVICE INFORMATION >
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OUTLINE
The auto light control system uses an optical sensor that detects outside brightness.
When the lighting switch is in "AUTO" position, it automatically turns on/off the parking lamps and the head-
lamps in accordance with the ambient light. Sensitivity can be adjusted in four steps. For the details of the set-
ting, refer to LT-40, "
Preliminary Check" .
Optical sensor ground is supplied
• to optical sensor terminal 3
• through BCM (body control module) terminal 18.
When ignition switch is turned to “ON” position and when outside brightness is darker than prescribed level,
input is supplied
• to BCM terminal 58
• through optical sensor terminal 4.
The headlamps will then illuminate. For a description of headlamp operation, refer to LT- 5 , "
System Descrip-
tion" .
COMBINATION SWITCH READING FUNCTION
Refer to BCS-3, "System Description" .
EXTERIOR LAMP BATTERY SAVER CONTROL
When the combination switch (lighting switch) is in the AUTO position, and the ignition switch is turned from
ON or ACC to OFF, and one of the front doors is opened, the battery saver control feature is activated.
Under this condition, the headlamps remain illuminated for 5 minutes, then the headlamps are turned off.
Exterior lamp battery saver control mode can be changed by the function setting of CONSULT-II.
DELAY TIMER FUNCTION
When the ignition switch is ON and auto light switch is ON, the BCM turns on/off the headlamps. In delay timer
function, ignition is OFF, auto light sensor power source is OFF and the headlamps are not turned on/off by the
BCM. On condition that:
• when the state of ignition switch ON or ACC is ON and output judgment by auto light function is headlamp
ON changes to ignition switch and ACC are OFF and any door switch is ON, output judgment by BCM
should be headlamp ON for 5 minutes by timer. After time out, output judgment by BCM should be headlamp
OFF.
• when the state of any door switch is turned to ON from OFF while 45 second or 5 minute timer is counting,
timer stops, and restarts counting for 5 minutes, then BCM judges output as headlamp ON. After time out,
BCM judges output as headlamp OFF.
• when the state of front door switch (LH), front door switch (RH), rear door switch LH, rear door switch RH or
back door latch (door ajar switch) is ON turns to all door switches are OFF while 45 second or 5 minute timer
is counting, timer stops, and restarts counting for 45 seconds, then BCM judges output as headlamp ON.
After timer out, BCM judges output as headlamp OFF.
• when the state is ignition switch ON or ACC is ON or auto light switch OFF while timer is counting, timer
stops counting and BCM turns on/off lamps according to headlamp function, front fog lamp function, auto
light function and headlamp battery save function.
Delay timer control mode can be changed by the function setting of CONSULT-II.
CAN Communication System DescriptionINFOID:0000000003533370
Refer to LAN-4, "CAN Communication System" .
Major Component and FunctionsINFOID:0000000003533371
Components Functions
BCM• Turns on/off circuits of tail light and headlamp according to signals from light sensor, lighting switch
(AUTO), front door switch LH, front door switch RH, rear door switch, back door latch (door ajar
switch), and ignition switch (ON, OFF).
Optical sensor • Converts ambient light (lux) to voltage, and sends it to BCM. (Detects lightness of 50 to 1,300 lux)

LT-40
< SERVICE INFORMATION >
AUTO LIGHT SYSTEM
How to Proceed with Trouble Diagnosis
INFOID:0000000003533376
1. Confirm the symptom or customer complaint.
2. Understand operation description and function description. Refer to LT-34, "
System Description" .
3. Carry out the Preliminary Check. Refer to LT-40, "
Preliminary Check" .
4. Check symptom and repair or replace the component. Refer to LT-42, "
Trouble Diagnosis Chart by Symp-
tom" .
5. Does the auto light system operate normally? If YES: GO TO 6. If NO: GO TO 4.
6. Inspection End.
Preliminary CheckINFOID:0000000003533377
SETTING CHANGE FUNCTIONS
• Sensitivity of auto light system can be adjusted using CONSULT-II. Refer to LT-40, "CONSULT-II Function
(BCM)" .
CHECK POWER SUPPLY AND GROUND CIRCUIT FOR BCM
Refer to BCS-15, "BCM Power Supply and Ground Circuit Inspection" .
CHECK POWER SUPPLY AND GROUND CIRCUIT FOR IPDM E/R
Refer to PG-26, "IPDM E/R Power/Ground Circuit Inspection" .
CONSULT-II Function (BCM)INFOID:0000000003533378
Refer to BCS-16, "CONSULT-II Function (BCM)".
CONSULT-II START PROCEDURE
Refer to GI-36, "CONSULT-II Start Procedure" .
WORK SUPPORT
Work Support Setting Item
• Delay timer setting can be selected and set from eight modes.
• Sensitivity of auto light can be selected and set from four modes.
DATA MONITOR
Display Item List
Work item Description
CUSTOM A/LIGHT SETTINGAuto light sensitivity can be changed in this mode. Sensitivity can be adjusted in four modes.
• MODE 1 (Normal-default)/ MODE 2 (Desensitized)/MODE 3 (Sensitive)/MODE4 (Insensitive)
ILL DELAY SETAuto light delay off timer period can be changed in this mode. Selects auto light delay off timer period
among eight modes.
• MODE 1 (45 sec.)/MODE 2 (OFF)/MODE 3 (30 sec.)/MODE 4 (60 sec.)/MODE 5 (90 sec.)/MODE
6 (120 sec.)/MODE 7 (150 sec.)/MODE 8 (180 sec.)
Monitor item Contents
IGN ON SW "ON/OFF" Displays "IGN position (ON)/OFF, ACC position (OFF)" judged from the ignition switch signal.
ACC ON SW "ON/OFF" Displays "ACC (ON)/OFF, Ignition OFF (OFF)" status judged from ignition switch signal.
HI BEAM SW "ON/OFF"Displays status (high beam switch: ON/Others: OFF) of high beam switch judged from lighting
switch signal.
HEAD LAMP SW 1 "ON/OFF"Displays status (headlamp switch 1: ON/Others: OFF) of headlamp switch 2 judged from light-
ing switch signal.
HEAD LAMP SW 2 "ON/OFF"Displays status (headlamp switch 2: ON/Others: OFF) of headlamp switch 2 judged from light-
ing switch signal.
LIGHT SW 1ST "ON/OFF"Displays status (lighting switch 1st position: ON/Others: OFF) of lighting switch judged from
lighting switch signal.

AUTO LIGHT SYSTEM
LT-41
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ACTIVE TEST
Display Item List
SELF-DIAGNOSTIC RESULTS
Display Item List
CONSULT-II Function (IPDM E/R)INFOID:0000000003533379
Refer to PG-18, "CONSULT-II Function (IPDM E/R)" .
CONSULT-II START PROCEDURE
Refer to GI-36, "CONSULT-II Start Procedure" .
DATA MONITOR
All Items, Main Items, Select Item Menu
AUTO LIGHT SW "ON/OFF"Displays status of the lighting switch as judged from the lighting switch signal. (AUTO position:
ON/Other than AUTO position: OFF)
PASSING SW "ON/OFF"Displays status (flash-to-pass switch: ON/Others: OFF) of flash-to-pass switch judged from
lighting switch signal.
FR FOG SW "ON/OFF"Displays status (front fog lamp switch: ON/Others: OFF) of front fog lamp switch judged from
lighting switch signal.
DOOR SW-DR "ON/OFF"Displays status of the front door LH as judged from the front door switch LH signal. (Door is
open: ON/Door is closed: OFF)
DOOR SW-AS "ON/OFF"Displays status of the front door RH as judged from the front door switch RH signal. (Door is
open: ON/Door is closed: OFF)
DOOR SW-RR "ON/OFF"Displays status of the rear door as judged from the rear door switch (RH) signal. (Door is open:
ON/Door is closed: OFF)
DOOR SW-RL "ON/OFF"Displays status of the rear door as judged from the rear door switch (LH) signal. (Door is open:
ON/Door is closed: OFF)
BACK DOOR SW "ON/OFF"Displays status of the back door as judged from the back door latch (door ajar switch) signal.
(Door is open: ON/Door is closed: OFF)
TURN SIGNAL R "ON/OFF" Displays status (Turn right: ON/Others: OFF) as judged from lighting switch signal.
TURN SIGNAL L "ON/OFF" Displays status (Turn left: ON/Others: OFF) as judged from lighting switch signal.
CARGO LAMP SW "ON/OFF" Displays status of cargo lamp.
OPTICAL SENSOR [0 - 5V] Displays "ambient light (close to 5V when dark/close to 0V when light)" judged from optical sen-
sor signal. Monitor item Contents
Te s t i t e m D e s c r i p t i o n
TAIL LAMP Allows tail lamp relay to operate by switching ON-OFF.
HEAD LAMP Allows headlamp relay (HI, LO) to operate by switching ON-OFF.
FR FOG LAMP Allows fog lamp relay to operate by switching ON-OFF.
CARGO LAMP Allows cargo lamp to operate by switching ON-OFF.
Monitored item CONSULT-ll display Description
CAN communication CAN communication [U1000] Malfunction is detected in CAN communication.
CAN communication system CAN communication system 1 to 6 [U1000] Malfunction is detected in CAN system.

LT-42
< SERVICE INFORMATION >
AUTO LIGHT SYSTEM
NOTE:
Perform monitoring of IPDM E/R data with the ignition switch ON. When the ignition switch is at ACC, the dis-
play may not be correct.
ACTIVE TEST
Trouble Diagnosis Chart by SymptomINFOID:0000000003533380
Lighting Switch InspectionINFOID:0000000003533381
1.CHECK LIGHTING SWITCH INPUT SIGNAL
With CONSULT-II
Item nameCONSULT-II
screen displayDisplay or
unitMonitor item selection
Description
ALL
SIGNALSMAIN
SIGNALSSELECTION
FROM MENU
Parking, license plate
and tail lamps requestTAIL&CLR REQ ON/OFF×× ×Signal status input from BCM
Headlamp low beam re-
questHL LO REQ ON/OFF×× ×Signal status input from BCM
Headlamp high beam re-
questHL HI REQ ON/OFF×× ×Signal status input from BCM
Front fog lamps request FR FOG REQ ON/OFF×× ×Signal status input from BCM
Test item CONSULT-II screen display Description
Tail lamp relay output TAIL LAMPAllows tail lamp relay to operate by switching operation ON-OFF at your
option.
Headlamp relay (HI, LO) out-
put
LAMPSAllows headlamp relay (HI, LO) to operate by switching operation (OFF,
HI, LO) at your option (Headlamp high beam repeats ON-OFF every 1
second).
Front fog lamp relay outputAllows fog lamp relay to operate by switching operation ON-OFF at your
option.
Trouble phenomenon Malfunction system and reference
• Parking lamps and headlamps will not illuminate when out-
side of the vehicle becomes dark. (Lighting switch 1st posi-
tion and 2nd position operate normally.)
• Parking lamps and headlamp will not go out when outside of
the vehicle becomes light. (Lighting switch 1st position and
2nd position operate normally.)
• Headlamps go out when outside of the vehicle becomes
light, but parking lamps stay on.•Refer to LT- 4 0 , "
CONSULT-II Function (BCM)" .
•Refer to LT- 7 3 , "
Combination Switch Inspection" .
•Refer to LT- 4 3 , "
Optical Sensor System Inspection" .
If above systems are normal, replace BCM. Refer to BCS-24, "
BCM" .
Parking lamps illuminate when outside of the vehicle becomes
dark, but headlamps stay off. (Lighting switch 1st position and
2nd position operate normally.)•Refer to LT- 4 0 , "
CONSULT-II Function (BCM)" .
•Refer to LT- 4 3 , "
Optical Sensor System Inspection" .
If above systems are normal, replace BCM. Refer to BCS-24, "
BCM" .
Auto light adjustment system will not operate. (Lighting switch
AUTO, 1st position and 2nd position operate normally.)•Refer to LT- 4 3 , "
Optical Sensor System Inspection" .
If above system is normal, replace BCM. Refer to BCS-24, "
BCM" .
Auto light adjustment system will not operate.• CAN communication line to BCM inspection. Refer to BCS-18,
"CAN Communication Inspection Using CONSULT-II (Self-Diagno-
sis)" .
Shut off delay feature will not operate.• CAN communication line inspection between BCM and combination
meter. Refer to BCS-18, "
CAN Communication Inspection Using
CONSULT-II (Self-Diagnosis)" .
•Refer toBL-25, "
Door Switch Check" .
If above system is normal, replace BCM. Refer to BCS-24, "
BCM" .

AUTO LIGHT SYSTEM
LT-43
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Select "BCM" on CONSULT-II. With "HEAD LAMP" data monitor,
make sure "AUTO LIGHT SW" turns ON-OFF linked with operation
of lighting switch.
Without CONSULT-II
Refer to LT-73, "
Combination Switch Inspection" .
OK or NG
OK >> Inspection End.
NG >> Check lighting switch. Refer to LT-73, "
Combination
Switch Inspection" .
Optical Sensor System InspectionINFOID:0000000003533382
1.CHECK OPTICAL SENSOR INPUT SIGNAL
With CONSULT-II
Select "BCM" on CONSULT-II. With "OPTICAL SENSOR" data mon-
itor, check difference in the voltage when the optical sensor is illumi-
nated and not illuminated.
NOTE:
Optical sensor must be completely subjected to work lamp light. If
the optical sensor is insufficiently illuminated, the measured value
may not satisfy the standard.
Without CONSULT-II
GO TO 2.
OK or NG
OK >> Inspection End.
NG >> GO TO 2.
2.CHECK OPTICAL SENSOR SIGNAL GROUND CIRCUIT
1. Turn ignition switch OFF.
2. Disconnect BCM connectors and optical sensor connector.
3. Check continuity (open circuit) between BCM harness connector
M18 terminal 18 and optical sensor harness connector M402
terminal 3.
4. Check continuity (short circuit) between BCM harness connector
M18 terminal 18 and ground.
OK or NG
OK >> GO TO 3.
NG >> Repair harness or connector.
3.CHECK OPTICAL SENSOR SIGNAL CIRCUITWhen lighting switch is in
AUTO position: AUTO LIGHT SW ON
SKIA4196E
Illuminated
OPTICAL SENSOR : 3.1V or more
Not illuminated
OPTICAL SENSOR : 0.6V or less
WKIA0486E
18 - 3 : Continuity should exist.
18 - Ground : Continuity should not exist.
WKIA1754E

HEADLAMP AIMING CONTROL
LT-45
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HEADLAMP AIMING CONTROL
System DescriptionINFOID:0000000003533384
The headlamp aiming system is controlled by the headlamp aiming switch.
Power is supplied at all times
• to ignition relay, located in the IPDM E/R (intelligent power distribution module engine room), and
• through 50A fusible link (letter f , located in the fuse and fusible link box)
• to BCM (body control module) terminal 70, and
• to headlamp low relay, located in the IPDM E/R (intelligent power distribution module engine room), and
• through 20A fuse (No. 53, located in the IPDM E/R)
• to CPU (central processing unit) of the IPDM E/R.
With the ignition switch in the ON or START position, power is supplied
• to ignition relay, located in the IPDM E/R, and
• through 10A fuse (No. 59, located in the fuse and relay box)
• to BCM terminal 38.
When the ignition switch is in the ACC or ON position, power is supplied
• through 10A fuse [No. 4, located in the fuse block (J/B)]
• to BCM terminal 11.
When the lighting switch is in the 2ND position or AUTO position (auto lights ON), the headlamp low relay
(located in the IPDM E/R) is energized. When energized, power is supplied
• through 15A fuse (No. 41, located in the IPDM E/R)
• through IPDM E/R terminal 26
• to front combination lamp LH and RH (headlamp aiming motor) terminal 8.
Ground is supplied
• to front combination lamp LH and RH (headlamp aiming motor) terminal 4
• through grounds E9, E15 and E24, and
• to front combination lamp LH and RH (headlamp aiming motor) terminal 7
• through headlamp aiming switch terminal 1
• through headlamp aiming switch terminal 2
• through grounds M57, M61 and M79.
With power and ground supplied, headlamp aiming motors operate according to the aiming switch position.

FRONT FOG LAMP
LT-49
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FRONT FOG LAMP
Component Parts and Harness Connector LocationINFOID:0000000003533388
System DescriptionINFOID:0000000003533389
Control of the fog lamps is dependent upon the position of the combination switch (lighting switch). The light-
ing switch must be in the 2ND position or AUTO position (LOW beam is ON) for front fog lamp operation.
When the lighting switch is placed in the fog lamp position, the BCM (body control module) receives input sig-
nal requesting the fog lamps to illuminate. When the headlamps are illuminated, this input signal is communi-
cated to the IPDM E/R (intelligent power distribution module engine room) across the CAN communication
lines. The CPU (central processing unit) of the IPDM E/R controls the front fog lamp relay coil. When acti-
vated, this relay directs power to the front fog lamps.
OUTLINE
Power is supplied at all times
• to ignition relay, located in the IPDM E/R,
• to front fog lamp relay, located in the IPDM E/R,
• through 20A fuse (No. 53, located in the IPDM E/R)
• to CPU of the IPDM E/R, and
• through 50A fusible link (letter f , located in the fuse and fusible link box)
• to BCM terminal 70.
When the ignition switch is in ON or START position, power is supplied
• to ignition relay, located in the IPDM E/R, and
• through 10A fuse (No. 59, located in the fuse and relay box)
• to BCM terminal 38.
Ground is supplied
• to BCM terminal 67
• through grounds M57, M61 and M79, and
• to IPDM E/R terminals 38 and 59
• through grounds E9, E15 and E24.
FOG LAMP OPERATION
The fog lamp switch is built into the combination switch. The lighting switch must be in the 2ND position or
AUTO position (LOW beam is ON) and the fog lamp switch must be ON for fog lamp operation.
WKIA3466E

LT-50
< SERVICE INFORMATION >
FRONT FOG LAMP
With the fog lamp switch in the ON position, the CPU of the IPDM E/R grounds the coil side of the fog lamp
relay. The fog lamp relay then directs power
• through 20A fuse (No. 56, located in the IPDM E/R)
• through IPDM E/R terminal 50
• to front turn/fog lamp LH terminal 1, and
• through IPDM E/R terminal 51
• to front turn/fog lamp RH terminal 1.
Ground is supplied
• to front turn/fog lamp LH and RH terminal 3
• through grounds E9, E15 and E24.
With power and ground supplied, the front fog lamps illuminate.
COMBINATION SWITCH READING FUNCTION
Refer to BCS-3, "System Description" .
EXTERIOR LAMP BATTERY SAVER CONTROL
When the combination switch (lighting switch) is in the 2ND position (ON), the fog lamp switch is ON, and the
ignition switch is turned from ON or ACC to OFF, the battery saver control feature is activated.
Under this condition, the fog lamps (and headlamps) remain illuminated for 5 minutes, then the fog lamps (and
headlamps) are turned off.
Exterior lamp battery saver control mode can be changed by the function setting of CONSULT-II.
CAN Communication System DescriptionINFOID:0000000003533390
Refer to LAN-4, "CAN Communication System" .