Can communication INFINITI QX56 2004 Factory Service Manual

CAN COMMUNICATION
LAN-11
[CAN]
C
D
E
F
G
H
I
J
L
MA
B
LAN
Revision: August 20072004 QX56
Input/output signal chart
T: Transmit R: Receive
Signals ECM TCMDriver
seat
con-
trol
unitCom-
bina-
tion
meterDis-
play
con-
trol
unitBCMStee r-
ing
angle
sen-
sorFront
air
con-
trolTran s-
fer
con-
trol
unitABS
actua-
tor
and
elec-
tric
unit
(con-
trol
unit)IPDM
E/R
A/T self-diagnosis signal R T
Stop lamp switch signal R T R
Parking brake switch signal T R
Battery voltage signal T R
Key switch signal R T
Ignition switch signal R T R
P range signal T R
Closed throttle position signal T R
Wide open throttle position signal T R
Engine speed signal T R R R R R
Engine status signal T R R
Engine coolant temperature signal T R R R
Accelerator pedal position signal T R R R
Fuel consumption monitor signalTR
TR
Turbine revolution signal R T
Output shaft revolution signal R T R
A/C switch signal R T
A/C compressor request signal T R R
Blower fan motor switch signal R T R
A/C switch/indicator signalTR
RT
Cooling fan speed request signal T R R
Position light request signal R T R
Low beam request signal T R
Low beam status signal RT
High beam request signal R T R
High beam status signal RT
Front fog light request signal T R
Day time running light request signal T R
Vehicle speed signalRRRT
RRRT RR R
Sleep wake up signal R T R
Door switch signal R R R T R
Turn indicator signal R T
Key fob ID signal R T
Key fob door unlock signal R T

LAN-12
[CAN]
CAN COMMUNICATION
Revision: August 20072004 QX56
Buzzer output signal R T
Fuel level sensor signal R T
ASCD SET lamp signal T R
ASCD CRUISE lamp signal T R
Malfunction indicator lamp signal T R
Fuel level low warning signal T R
Front wiper request signal T R
Front wiper stop position signal R T
Rear window defogger switch signal T R R
Rear window defogger control signal R R R T
Hood switch signal R T
Theft warning horn request signal T R
Horn chirp signal T R
Steering angle sensor signal T R
ABS warning lamp signal R T
VDC OFF indicator lamp signal R T
SLIP indicator lamp signal R T
Brake warning lamp signal R T
System setting signalRT
TR
Distance to empty signal T R
ASCD operation signal T R
ASCD OD cancel request T R
A/T CHECK indicator lamp signal T R
A/T position indicator lamp signal T R R
Tire pressure signal R T
Tire pressure data signal R T
1st position switch signal R T
4th position switch signal R T
Tow mode switch signal R T
A/T fluid temperature sensor signal T RSignals ECM TCMDriver
seat
con-
trol
unitCom-
bina-
tion
meterDis-
play
con-
trol
unitBCMSteer-
ing
angle
sen-
sorFront
air
con-
trolTrans-
fer
con-
trol
unitABS
actua-
tor
and
elec-
tric
unit
(con-
trol
unit)IPDM
E/R

CAN COMMUNICATION
LAN-13
[CAN]
C
D
E
F
G
H
I
J
L
MA
B
LAN
Revision: August 20072004 QX56
TYPE 4
System diagram

Ty p e 4
Input/output signal chart
T: Transmit R: Receive
PKIA8135E
Signals ECM TCMICC
sen-
sorICC
unitDriver
seat
con-
trol
unitCom-
bina-
tion
mete
rDis-
play
con-
trol
unitBCMStee r-
ing
angle
sen-
sorFront
air
con-
trolTra ns -
fer
con-
trol
unitABS
actu-
ator
and
elec-
tric
unit
(con-
trol
unit)IPD
M
E/R
A/T self-diagnosis signal R T
Stop lamp switch signal R T R
Parking brake switch signal T R
Battery voltage signal T R
Key switch signal R T
Ignition switch signal R T R
P range signal T R R
Closed throttle position signal T R R
Wide open throttle position signal T R
Engine speed signal T R R R R R R
Engine status signal T R R
Engine coolant temperature sig-
nalTR R R
Accelerator pedal position signal T R R R R
Fuel consumption monitor signalTR
TR
Turbine revolution signal R T R
Output shaft revolution signal R T R R
A/C switch signal R T
A/C compressor request signal T R R
Blower fan motor switch signal R T R

LAN-14
[CAN]
CAN COMMUNICATION
Revision: August 20072004 QX56
A/C switch/indicator signalTR
RT
Cooling fan speed request signal T R R
Position light request signal R T R
Low beam request signal T R
Low beam status signal RT
High beam request signal R T R
High beam status signal RT
Front fog light request signal T R
Day time running light request
signalTR
Vehicle speed signalR RRT
RRR R T R R R
Sleep wake up signal R T R
Door switch signal R R R T R
Turn indicator signal R T
Key fob ID signal R T
Key fob door unlock signal R T
Buzzer output signalRT
TR
Fuel level sensor signal R T
Malfunction indicator lamp signal T R
Fuel level low warning signal T R
Front wiper request signal R T R
Front wiper stop position signal R T
Rear window defogger switch sig-
nalTR R
Rear window defogger control
signalRRRT
Hood switch signalRT
Theft warning horn request signal T R
Horn chirp signalTR
Steering angle sensor signal T R
ABS warning lamp signal R T
VDC OFF indicator lamp signal R R T
SLIP indicator lamp signal R T
Brake warning lamp signal R T
VDC operation signal R T
ABS malfunction signal R TSignals ECM TCMICC
sen-
sorICC
unitDriver
seat
con-
trol
unitCom-
bina-
tion
mete
rDis-
play
con-
trol
unitBCMStee r-
ing
angle
sen-
sorFront
air
con-
trolTran s -
fer
con-
trol
unitABS
actu-
ator
and
elec-
tric
unit
(con-
trol
unit)IPD
M
E/R

CAN COMMUNICATION
LAN-15
[CAN]
C
D
E
F
G
H
I
J
L
MA
B
LAN
Revision: August 20072004 QX56
TCS malfunction signal R T
VDC malfunction signal R T
Brake pressure sensor signal R T
System setting signalRT
TR
Distance to empty signal T R
ASCD operation signal T R
ASCD OD cancel request T R
A/T CHECK indicator lamp signal T R
A/T position indicator lamp signal T R R R
Current gear position signal T R
Tire pressure signal R T
Tire pressure data signal R T
1st position switch signal R T
4th position switch signal R T
Tow mode switch signal R T
A/T fluid temperature sensor sig-
nalTR
ICC operation signal R R T
ICC OD cancel request signal R R T
ICC sensor signal T R
ICC system display signal T R
ICC steering switch signal T RSignals ECM TCMICC
sen-
sorICC
unitDriver
seat
con-
trol
unitCom-
bina-
tion
mete
rDis-
play
con-
trol
unitBCMStee r-
ing
angle
sen-
sorFront
air
con-
trolTra ns -
fer
con-
trol
unitABS
actu-
ator
and
elec-
tric
unit
(con-
trol
unit)IPD
M
E/R

LAN-16
[CAN]
CAN SYSTEM (TYPE 1)
Revision: August 20072004 QX56
CAN SYSTEM (TYPE 1)PFP:23710
System DescriptionUKS000P0
CAN (Controller Area Network) is a serial communication line for real time application. It is an on-vehicle mul-
tiplex communication line with high data communication speed and excellent error detection ability. Many elec-
tronic control units are equipped onto a vehicle, and each control unit shares information and links with other
control units during operation (not independent). In CAN communication, control units are connected with 2
communication lines (CAN H line, CAN L line) allowing a high rate of information transmission with less wiring.
Each control unit transmits/receives data but selectively reads required data only.
Component Parts and Harness Connector LocationUKS000P1
BKIA0118E

CAN SYSTEM (TYPE 1)
LAN-21
[CAN]
C
D
E
F
G
H
I
J
L
MA
B
LAN
Revision: August 20072004 QX56
Work FlowUKS0018G
1. When there are no indications of “AUTO DRIVE POS.”, “BCM” or “IPDM E/R” on “SELECT SYSTEM” dis-
play of CONSULT-II, print the “SELECT SYSTEM”.
2. Print all the data of “SELF-DIAG RESULTS” for “ENGINE”, “A/T”, “AUTO DRIVE POS.”, “BCM”, “ABS”
and “IPDM E/R” displayed on CONSULT-II.
3. Print all the data of “CAN DIAG SUPPORT MNTR” for “ENGINE”, “A/T”, “AUTO DRIVE POS.”, “BCM”,
“ABS” and “IPDM E/R” displayed on CONSULT-II.
4. Attach the printed sheet of “SELECT SYSTEM”, “SELF-DIAG RESULTS” and “CAN DIAG SUPPORT
MNTR” onto the check sheet. Refer to LAN-23, "
CHECK SHEET" .
5. Based on the indications of “SELECT SYSTEM” and the results of “CAN DIAG SUPPORT MNTR”, put
marks “v” onto the items with “No indication”, “NG” or “UNKWN” in the check sheet table. Refer to LAN-23,
"CHECK SHEET" .
NOTE:

If “NG” is displayed on “INITIAL DIAG (Initial diagnosis)” as “CAN DIAG SUPPORT MNTR” for the diag-
nosed control unit, replace the control unit.

The “CAN DIAG SUPPORT MNTR” items, which are not in check sheet table, are not related to diag-
nostic procedure on service manual.
So it is not necessary to check the status of the “CAN DIAG SUPPORT MNTR” items not in check
sheet table.
6. Check CAN communication line of the navigation system. Refer to AV-131, "
CAN Communication Line
Check" .
7. Attach the CAN DIAG SUPPORT MONITOR check sheet onto the check sheet. Refer to LAN-23,
"CHECK SHEET" .
PKIA2093E
PKIA8260E
PKIA8343E

LAN-22
[CAN]
CAN SYSTEM (TYPE 1)
Revision: August 20072004 QX56
8. Mark the “NG” or “UNKWN” item of the check sheet table with “v” from the result of CAN DIAG SUPPORT
MONITOR check sheet. Refer to LAN-23, "
CHECK SHEET" .
NOTE:
If “NG” is displayed on “CAN COMM” as “CAN DIAG SUPPORT MONITOR” for the diagnosed control
unit, replace the control unit. Refer to AV- 1 3 1 , "
CAN Communication Line Check" .
9. According to the check sheet results (example), start inspection. Refer to LAN-25, "
CHECK SHEET
RESULTS (EXAMPLE)" .

CAN SYSTEM (TYPE 1)
LAN-39
[CAN]
C
D
E
F
G
H
I
J
L
MA
B
LAN
Revision: August 20072004 QX56
Case 15
Check CAN communication circuit. Refer to LAN-48, "CAN Communication Circuit Check" .
Case 16
Check IPDM E/R ignition relay circuit continuously sticks “OFF”. Refer to LAN-49, "IPDM E/R Ignition Relay
Circuit Check" .
PKIA8064E
PKIA8065E

LAN-48
[CAN]
CAN SYSTEM (TYPE 1)
Revision: August 20072004 QX56
IPDM E/R Circuit CheckUKS0018V
1. CHECK CONNECTOR
1. Turn ignition switch OFF.
2. Disconnect the negative battery terminal.
3. Check terminals and connector of IPDM E/R for damage, bend and loose connection (control module side
and harness side).
OK or NG
OK >> GO TO 2.
NG >> Repair terminal or connector.
2. CHECK HARNESS FOR OPEN CIRCUIT
1. Disconnect IPDM E/R connector.
2. Check resistance between IPDM E/R harness connector E122
terminals 39 (W) and 40 (R).
OK or NG
OK >> Replace IPDM E/R.
NG >> Repair harness between IPDM E/R and harness con-
nector E152.
CAN Communication Circuit CheckUKS0018W
1. CHECK CONNECTOR
1. Turn ignition switch OFF.
2. Disconnect the negative battery terminal.
3. Disconnect the following module and control unit connectors and check terminals for deformation, discon-
nection, looseness or damage.
–ECM
–A/T assembly
–Driver seat control unit
–Combination meter
–Display control unit
–BCM
–Steering angle sensor
–Front air control
–ABS actuator and electric unit (control unit)
–IPDM E/R
OK or NG
OK >> GO TO 2.
NG >> Repair or replace as necessary.39 (W) - 40 (R) : Approx. 108 - 132Ω
PKIA8141E