Page 746 of 3371
BCS-1
BODY CONTROL SYSTEM
K ELECTRICAL
CONTENTS
C
D
E
F
G
H
I
J
L
M
SECTION BCS
A
B
BCS
Revision: August 20072004 QX56 PRECAUTIONS .......................................................... 2
Precautions for Supplemental Restraint System
(SRS) “AIR BAG” and “SEAT BELT PRE-TEN-
SIONER” .................................................................. 2
BCM (BODY CONTROL MODULE) ........................... 3
System Description .................................................. 3
BCM FUNCTION ................................................... 3
COMBINATION SWITCH READING FUNCTION ..... 3
CAN COMMUNICATION CONTROL .................... 6
BCM STATUS CONTROL ..................................... 6
SYSTEMS CONTROLLED BY BCM DIRECTLY ..... 7
SYSTEMS CONTROLLED BY BCM AND IPDM
E/R ........................................................................ 7
MAJOR COMPONENTS AND CONTROL SYS-
TEM ....................................................................... 7CAN Communication System Description ................ 8
Schematic ................................................................. 9
CONSULT-II Function (BCM) ................................. 11
CONSULT-II OPERATION ................................... 11
ITEMS OF EACH PART ...................................... 12
WORK SUPPORT ............................................... 12
CAN Communication Inspection Using CONSULT-
II (Self-Diagnosis) ................................................... 13
Configuration .......................................................... 13
DESCRIPTION .................................................... 13
READ CONFIGURATION PROCEDURE ............ 13
WRITE CONFIGURATION PROCEDURE .......... 16
Removal and Installation of BCM ........................... 19
REMOVAL ........................................................... 19
INSTALLATION ................................................... 19
Page 748 of 3371
BCM (BODY CONTROL MODULE)
BCS-3
C
D
E
F
G
H
I
J
L
MA
B
BCS
Revision: August 20072004 QX56
BCM (BODY CONTROL MODULE)PFP:284B2
System DescriptionEKS007GE
BCM (body control module) controls the operation of various electrical units installed on the vehicle.
BCM FUNCTION
BCM has a combination switch reading function for reading the operation of combination switches (light, wiper
washer, turn signal) in addition to the function for controlling the operation of various electrical components.
Also, it functions as an interface that receives signals from the front air control, and sends signals to ECM
using CAN communication.
COMBINATION SWITCH READING FUNCTION
1. Description
BCM reads combination switch (light, wiper) status, and controls various electrical components accord-
ing to the results.
BCM reads information of a maximum of 20 switches by combining five output terminals (OUTPUT 1-5)
and five input terminals (INPUT 1-5).
2. Operation description
BCM activates transistors of output terminals (OUTPUT 1-5) periodically and allows current to flow in
turn.
If any (1 or more) of the switches are turned ON, circuit of output terminals (OUTPUT 1-5) and input ter-
minals (INPUT 1-5) becomes active.
At this time, transistors of output terminals (OUTPUT 1-5) are activated to allow current to flow. When
voltage of input terminals (INPUT 1-5) corresponding to that switch changes, interface in BCM detects
voltage change and BCM determines that switch is ON.
3. BCM - Operation table of combination switch
BCM reads operation status of combination switch by the combination shown in the following table.
LIIA0757E
Page 749 of 3371
BCS-4
BCM (BODY CONTROL MODULE)
Revision: August 20072004 QX56
NOTE:
Headlamp has a dual system switch.
4. Example operation: (When lighting switch 1st position turned ON)
When lighting switch 1st position is turned ON, contact in combination switch turns ON. At this time if
OUTPUT 4 transistor is activated, BCM detects that voltage changes in INPUT 5.
When OUTPUT 4 transistor is ON, BCM detects that voltage changes in INPUT 5, and judges lighting
switch 1st position is ON. Then BCM sends tail lamp ON signal to IPDM E/R using CAN communica-
tion.
When OUTPUT 4 transistor is activated again, BCM detects that voltage changes in INPUT 5 and rec-
ognizes that lighting switch 1st position is continuously ON.
SKIA4959E
Page 750 of 3371
BCM (BODY CONTROL MODULE)
BCS-5
C
D
E
F
G
H
I
J
L
MA
B
BCS
Revision: August 20072004 QX56
NOTE:
Each OUTPUT terminal transistor is activated at 10 ms intervals. Therefore, after a switch is turned ON,
electrical loads are activated with a time delay. But this time delay is so short that it cannot be noticed.
5. Operation mode
Combination switch reading function has operation modes as follows:
Normal status
When BCM is not in sleep status, OUTPUT terminals (1-5) each turn ON-OFF every 10 ms.
Sleep status
LIIA0760E
Page 751 of 3371
BCS-6
BCM (BODY CONTROL MODULE)
Revision: August 20072004 QX56
When BCM is in sleep mode, transistors of OUTPUT 1 and 5 stop the output, and BCM enters low-cur-
rent-consumption mode. OUTPUTS (2, 3, and 4) turn ON-OFF at 60 ms intervals, and receives lighting
switch input only.
CAN COMMUNICATION CONTROL
CAN communication allows a high rate of information through the two communication lines (CAN-L, CAN-H)
connecting the various control units in the system. Each control unit transmits/receives data, but selectively
reads required data only.
BCM STATUS CONTROL
BCM changes its status depending on the operation status in order to save power consumption.
1. CAN communication status
With ignition switch ON, CAN communicates with other control units normally.
Control by BCM is being operated properly.
When ignition switch is OFF, switching to sleep mode is possible.
Even when ignition switch is OFF, if CAN communication with IPDM E/R and combination meter is
active, CAN communication status is active.
2. Sleep transient status
This status shuts down CAN communication when ignition switch is turned OFF.
It transmits sleep request signal to IPDM E/R and combination meter.
Two seconds after CAN communication of all control units stops, CAN communication switches to inac-
tive status.
3. CAN communication inactive status
With ignition switch OFF, CAN communication is not active.
With ignition switch OFF, control performed only by BCM is active.
Three seconds after CAN communication of all control units stops, CAN communication switches to
inactive status.
4. Sleep status
WKIA4093E
Page 752 of 3371
BCM (BODY CONTROL MODULE)
BCS-7
C
D
E
F
G
H
I
J
L
MA
B
BCS
Revision: August 20072004 QX56
BCM is activated with low current consumption mode.
CAN communication is not active.
When CAN communication operation is detected, it switches to CAN communication status.
When a state of the following switches changes, it switches to CAN communication state:
–Key switch
–Hazard switch
–Door lock/unlock switch
–Front door switch (LH, RH)
–Rear door switch (LH, RH)
–Back door switch
–Combination switch (passing, lighting switch 1st position, front fog lamp)
–Keyfob (lock/unlock signal)
–Door lock assembly LH (key cylinder switch)
When control performed only by BCM is required by switch, it shifts to CAN communication inactive
mode.
Status of combination switch reading function is changed.
SYSTEMS CONTROLLED BY BCM DIRECTLY
Power door lock system. Refer to BL-16, "POWER DOOR LOCK SYSTEM" .
Remote keyless entry system. Refer to BL-44, "REMOTE KEYLESS ENTRY SYSTEM" .
Power window system. Refer to GW-15, "POWER WINDOW SYSTEM" . NOTE
Sunroof system. Refer to RF-10, "SUNROOF" . NOTE
Room lamp timer. Refer to LT- 1 2 9 , "INTERIOR ROOM LAMP" .
Warning chime system. Refer to DI-43, "WARNING CHIME" .
Turn signal and hazard warning lamps system. Refer to LT-80, "TURN SIGNAL AND HAZARD WARNING
LAMPS" .
NOTE:
Power supply only. No system control.
SYSTEMS CONTROLLED BY BCM AND IPDM E/R
Panic system. Refer to BL-44, "REMOTE KEYLESS ENTRY SYSTEM" .
Theft warning system. Refer to BL-75, "VEHICLE SECURITY (THEFT WARNING) SYSTEM" .
IVIS (NATS) system. Refer to BL-138, "IVIS (INFINITI VEHICLE IMMOBILIZER SYSTEM-NATS)" .
Headlamp, daytime light, fog lamp, tail lamp, auto light and battery saver control systems. Refer to LT- 6 ,
"HEADLAMP (FOR USA)" , LT-34, "HEADLAMP (FOR CANADA) - DAYTIME LIGHT SYSTEM -" , LT-69,
"FRONT FOG LAMP" , LT- 1 0 8 , "PARKING, LICENSE PLATE AND TAIL LAMPS" , or LT- 4 7 , "AUTO
LIGHT SYSTEM" .
Front wiper and washer system. Refer to WW-4, "FRONT WIPER AND WASHER SYSTEM" .
Rear wiper and washer system. Refer to WW-33, "REAR WIPER AND WASHER SYSTEM" .
Rear window defogger system. Refer to GW-78, "REAR WINDOW DEFOGGER" .
MAJOR COMPONENTS AND CONTROL SYSTEM
System Input Output
Remote keyless entry system Keyfob
All-door locking actuator
Back door opener actuator
Turn signal lamp (LH, RH)
Power door lock system
Front power door lock/unlock
switch (LH, RH)
All door switch
Key switchAll-door locking actuator
Power supply (IGN) to power window and
sunroofIgnition power supply Power supply to power window and sunroof system
Page 753 of 3371
BCS-8
BCM (BODY CONTROL MODULE)
Revision: August 20072004 QX56
CAN Communication System DescriptionEKS007GF
Refer to LAN-5, "CAN COMMUNICATION" .
Power supply (BAT) to power window and
sunroofBattery power supply Power supply to power window and sunroof system
Panic alarm
Key switch
KeyfobIPDM E/R
Auto light system
Auto light sensor
Combination switchIPDM E/R
Battery saver control
Ignition switch
Combination switch
Front door switch LH
Front door switch RHIPDM E/R
Headlamp Combination switch IPDM E/R
Tail lamp Combination switch IPDM E/R
Fog lamp Combination switch IPDM E/R
Turn signal lamp Combination switch
Turn signal lamp
Combination meter
Hazard lamp Hazard switch
Turn signal lamp
Combination meter
Room lamp timer
Key switch
Keyfob
Main power window and door
lock/unlock switch
Front door lock assembly LH
(key cylinder switch)
All door switchInterior room lamp
Key warning chime
Key switch
Front door switch LHCombination meter (warning buzzer)
Light warning chime
Combination switch
Key switch
Front door switch LHCombination meter (warning buzzer)
Vehicle-speed-sensing intermittent wiper
Combination switch
Combination meterIPDM E/R
Rear window defogger Rear window defogger switch IPDM E/R
Air conditioner switch signal Front air control ECM
Blower fan switch signal Front air control ECM
Low tire pressure warning system Remote keyless entry receiver
Combination meter
Display control unit
Trailer tow Combination switch Trailer turn signal lamp
Vehicle security system
Remote keyless entry receiver
(Keyfob)
Main power window and door
lock/unlock switch
Power window and door lock/
unlock switch RH
Front door lock assembly LH
(key cylinder switch)
All door switch
Glass hatch ajar switch
IPDM E/R
Security indicator lamp System Input Output
Page 754 of 3371
BCM (BODY CONTROL MODULE)
BCS-9
C
D
E
F
G
H
I
J
L
MA
B
BCS
Revision: August 20072004 QX56
SchematicEKS007GG
WKWA3104E
