2004 INFINITI QX56 Can communication

HEADLAMP (FOR CANADA) - DAYTIME LIGHT SYSTEM -
LT-35
C
D
E
F
G
H
I
J
L
MA
B
LT
Revision: August 20072004 QX56
System DescriptionEKS007AB
Daytime light system turns on daytime light lamps while driving. Daytime light lamps are not turned on if
engine is activated with parking brake applied. Release parking brake to turn on daytime light lamps. The
lamps turn off when lighting switch is in the 2ND position or AUTO position (Headlamp is "ON") and when light-
ing switch is in the PASSING position. (Daytime light lamps are not turned off only by parking brake itself.)
A parking brake signal and engine run or stop signal are sent to BCM (body control module) by CAN commu-
nication line.
OUTLINE
Power is supplied at all times

through 10A fuse [No. 19, located in the fuse block (J/B)]

to combination meter terminal 8, and

through 50A fusible link (letter f , located in the fuse and fusible link box)

to BCM terminal 70, and

through 10A fuse [No. 45, located in the IPDM E/R (intelligent power distribution module engine room)]

to daytime light relay terminals 2 and 5.
When the ignition switch is in ON or START position, power is supplied

through 10A fuse [No. 14, located in the fuse block (J/B)]

to combination meter terminal 24, and

through 10A fuse (No. 59, located in the fuse and relay box)

to BCM terminal 38.
Ground is supplied

to combination meter terminal 17 and

to BCM terminal 67

through grounds M57, M61 and M79.
DAYTIME LIGHT OPERATION
With the engine running, the lighting switch in the OFF or 1ST position and parking brake released, the IPDM
E/R receives input requesting the daytime lights illuminate. This input is communicated across the CAN com-
munication lines. The CPU (central processing unit) of the IPDM E/R controls the daytime light relay coil.
When energized, this relay directs power

through daytime light relay terminal 3

to front combination lamp LH terminal 2

through front combination lamp LH terminal 6

through IPDM E/R terminal 55

through 10A fuse (No. 35, located in the IPDM E/R)

through 10A fuse (No. 34, located in the IPDM E/R)

through IPDM E/R terminal 56

to front combination lamp RH terminal 6.
Ground is supplied

to combination lamp RH terminal 2

through grounds E9, E15 and E24.
With power and ground supplied, the daytime lights illuminate. The high beam headlamps are now wired in
series and illuminate at a reduced intensity.
COMBINATION SWITCH READING FUNCTION
Refer to BCS-3, "COMBINATION SWITCH READING FUNCTION" .
AUTO LIGHT OPERATION
For auto light operation, refer to LT-4 8, "System Description" in AUTO LIGHT SYSTEM.
CAN Communication System DescriptionEKS007AC
Refer to LAN-5, "CAN COMMUNICATION" .

HEADLAMP (FOR CANADA) - DAYTIME LIGHT SYSTEM -
LT-45
C
D
E
F
G
H
I
J
L
MA
B
LT
Revision: August 20072004 QX56
2. CHECK DAYTIME LIGHT RELAY
1. Apply battery voltage to daytime light relay terminal 2 and ground terminal 1.
2. Check continuity between terminals 3 and 5.
OK or NG
OK >> GO TO 3.
NG >> Replace daytime light relay.
3. CHECK DAYTIME LIGHT RELAY CIRCUIT
1. Disconnect IPDM E/R connector E122.
2. Check continuity between daytime light relay connector E103
terminal 1 (BR) and IPDM E/R harness connector E122 terminal
44 (BR).
OK or NG
OK >> GO TO 4.
NG >> Repair harness or connector.
4. CHECK INPUT SIGNAL
1. Connect daytime light relay and IPDM E/R connector.
2. Start engine and release parking brake. Headlamp switch OFF.
3. Select “IPDM E/R” on CONSULT-II. With data monitor, make
sure “DTRL REQ” turns ON-OFF linked with operation of park-
ing brake switch.
OK or NG
OK >> Replace IPDM E/R. Refer to PG-29, "Removal and
Installation of IPDM E/R" .
NG >> GO TO 5.
5. CHECKING CAN COMMUNICATIONS
Select “BCM” by CONSULT-II and perform self-diagnosis for BCM.
Displayed self-diagnosis results
NO DTC>>Replace BCM. Refer to BCS-19, "Removal and Installa-
tion of BCM" .
CAN COMM CIRCUIT>> Check BCM CAN communication system.
Refer to BCS-13, "
CAN Communication Inspection
Using CONSULT-II (Self-Diagnosis)" . 3 - 5 : Continuity should exist.
WKIA1447E
44 (BR) - 1 (BR) : Continuity should exist.
WKIA2069E
Parking brake ON : DTRL REQ ON
Parking brake OFF : DTRL REQ OFF
WKIA1449E
SKIA1039E

LT-48
AUTO LIGHT SYSTEM
Revision: August 20072004 QX56
System DescriptionEKS007AP
Automatically turns on/off the parking lamps and the headlamps in accordance with ambient light.
Timing for when the lamps turn on/off can be selected using four modes.
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-55, "
SETTING CHANGE FUNCTIONS" .
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- 6 , "
System Descrip-
tion" .
COMBINATION SWITCH READING FUNCTION
Refer to BCS-3, "COMBINATION SWITCH READING FUNCTION" .
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 head-
lamp 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 (driver side), front door switch (passenger side), 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 DescriptionEKS007AQ
Refer to LAN-5, "CAN COMMUNICATION" .
Major Components and FunctionsEKS007AR
Components Functions
BCM

Turns on/off circuits of tail light and headlamp according to signals from light sensor, lighting switch
(AUTO), driver door switch, passenger door switch, rear door 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)

AUTO LIGHT SYSTEM
LT-57
C
D
E
F
G
H
I
J
L
MA
B
LT
Revision: August 20072004 QX56
CONSULT-II Function (BCM)EKS007AY
CONSULT-II can display each diagnostic item using the diagnostic test modes shown following.
CONSULT-II OPERATION
CAUTION:
If CONSULT-II is used with no connection of CONSULT-II CONVERTER, malfunctions might be
detected in self-diagnosis depending on control unit which carries out CAN communication.
1. With the ignition switch OFF, connect CONSULT-II and CON-
SULT-II CONVERTER to the data link connector, then turn igni-
tion switch ON.
2. Touch “START (NISSAN BASED VHCL)”.
3. Touch “BCM” on “SELECT SYSTEM” screen.
If “BCM” is not indicated, go to GI-39, "
CONSULT-II Data Link
Connector (DLC) Circuit" .
BCM diagnostic
test itemDiagnostic mode Description
Inspection by partWORK SUPPORTSupports inspections and adjustments. Commands are transmitted to the BCM
for setting the status suitable for required operation, input/output signals are
received from the BCM and received data is displayed.
DATA MONITOR Displays BCM input/output data in real time.
ACTIVE TEST Operation of electrical loads can be checked by sending drive signal to them.
SELF-DIAG RESULTS Displays BCM self-diagnosis results.
CAN DIAG SUPPORT MNTR The result of transmit/receive diagnosis of CAN communication can be read.
ECU PART NUMBER BCM part number can be read.
CONFIGURATION Performs BCM configuration read/write functions.
BBIA0369E
BCIA0029E
BCIA0030E

LT-60
AUTO LIGHT SYSTEM
Revision: August 20072004 QX56
Display Item List
CONSULT-II Function (IPDM E/R)EKS007AZ
CONSULT-II can display each diagnostic item using the diagnostic test modes shown following.
CONSULT-II OPERATION
CAUTION:
If CONSULT-II is used with no connection of CONSULT-II CONVERTER, malfunctions might be
detected in self-diagnosis depending on control unit which carries out CAN communication.
1. With the ignition switch OFF, connect CONSULT-II and CON-
SULT-II CONVERTER to the data link connector, then turn the
ignition switch ON.
2. Touch “START (NISSAN BASED VHCL)”.
3. Touch “IPDM E/R” on “SELECT SYSTEM” screen.
If “IPDM E/R” is not displayed, refer to GI-39, "
CONSULT-II Data
Link Connector (DLC) Circuit" .
Monitored item CONSULT-ll display Description
CAN communication CAN communication [U1000] Malfunction is detected in CAN communication.
CAN communication systemCAN communication system 1 to 6
[U1000]Malfunction is detected in CAN system.
IPDM E/R diagnostic mode Description
SELF-DIAG RESULTS Displays IPDM E/R self-diagnosis results.
DATA MONITOR Displays IPDM E/R input/output data in real time.
CAN DIAG SUPPORT MNTR The result of transmit/receive diagnosis of CAN communication can be read.
ACTIVE TEST Operation of electrical loads can be checked by sending drive signal to them.
BBIA0369E
BCIA0029E
BCIA0030E

LT-62
AUTO LIGHT SYSTEM
Revision: August 20072004 QX56
Trouble Diagnosis Chart by SymptomEKS007B0
Lighting Switch InspectionEKS007B1
1. CHECK LIGHTING SWITCH INPUT SIGNAL
With CONSULT-II
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- 1 0 0 , "
Combination Switch Inspection" .
OK or NG
OK >> Inspection End.
NG >> Check lighting switch. Refer to LT-100, "
Combination
Switch Inspection" .
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. Test item CONSULT-II screen display Description
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-58, "WORK SUPPORT" .

Refer to LT-62, "Lighting Switch Inspection" .

Refer to LT-63, "Optical Sensor System Inspection" .
If above systems are normal, replace BCM. Refer to BCS-19,
"Removal and Installation of 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-58, "WORK SUPPORT" .

Refer to LT-63, "Optical Sensor System Inspection" .
If above systems are normal, replace BCM. Refer to BCS-19,
"Removal and Installation of BCM" .
Auto light adjustment system will not operate. (Lighting switch
AUTO, 1st position and 2nd position operate normally.)

Refer to LT-63, "Optical Sensor System Inspection" .
If above system is normal, replace BCM. Refer to BCS-19, "
Removal
and Installation of BCM" .
Auto light adjustment system will not operate.

CAN communication line to BCM inspection. Refer to BCS-13,
"CAN Communication Inspection Using CONSULT-II (Self-Diagno-
sis)" .
Shut off delay feature will not operate.

CAN communication line inspection between BCM and combina-
tion meter. Refer to BCS-13, "
CAN Communication Inspection
Using CONSULT-II (Self-Diagnosis)" .

Refer to BL-31, "Door Switch Check" .
If above system is normal, replace BCM. Refer to BCS-19, "
Removal
and Installation of BCM" .
When lighting switch is in
AUTO position: AUTO LIGHT SW ON
SKIA4196E

FRONT FOG LAMP
LT-69
C
D
E
F
G
H
I
J
L
MA
B
LT
Revision: August 20072004 QX56
FRONT FOG LAMPPFP:26150
Component Parts and Harness Connector LocationEKS007B4
System DescriptionEKS007B5
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, and

to front fog lamp relay, located in the IPDM E/R, and

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
WKIA3395E

LT-70
FRONT FOG LAMP
Revision: August 20072004 QX56

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.
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, "COMBINATION SWITCH READING FUNCTION" .
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 DescriptionEKS007B6
Refer to LAN-5, "CAN COMMUNICATION" .