service INFINITI QX56 2007 Factory Service Manual

LAN-28
< SERVICE INFORMATION >[CAN FUNDAMENTAL]
TROUBLE DIAGNOSES WORK FLOW
• Refer to LAN-61, "Malfunction Area Chart".
Past Error — Open Circuit —
Review CAN communication signal chart based on information received from the interview with the customer
and on past error information from SELF-DIAG RESULTS and CAN DIAG SUPPORT MNTR.
SKIB8894E

TROUBLE DIAGNOSES WORK FLOW
LAN-29
< SERVICE INFORMATION >[CAN FUNDAMENTAL]
C
D
E
F
G
H
I
J
L
MA
B
LAN
N
O
P
1. SELF-DIAG RESULTS: Inspect the control units indicating “U1000” or “U1001” on SELF-DIAG RESULTS.
2. CAN DIAG SUPPORT MNTR (with PAST): Check the CAN DIAG SUPPORT MNTR (with PAST) of units
indicating “U1000” or “U1001” on SELF-DIAG RESULTS. Draw a line on the diagnosis sheet to indicate
the possible error circuit.
NOTE:
For the details of each indication on CAN DIAG SUPPORT MNTR, refer to LAN-40, "
CAN Diagnostic Sup-
port Monitor".
a. Reception item of “ENGINE”: “VDC/TCS/ABS”, “3” is indicated in the “PAST”. This means ECM could not
receive the signal from ABS in the past. Draw a line between ECM and ABS (line 2-a in the figure).
SKIB8731E

LAN-30
< SERVICE INFORMATION >[CAN FUNDAMENTAL]
TROUBLE DIAGNOSES WORK FLOW
b. Reception item of “METER”: “VDC/TCS/ABS”, “3” is indicated in the “PAST”. This means M&A could not
receive the signal from ABS in the past. Draw a line between M&A and ABS (line 2-b in the figure).
c. Reception item of “TRANSMISSION”: “VDC/TCS/ABS”, “3” is indicated in the “PAST”. This means TCM
could not receive the signal from ABS in the past. Draw a line between TCM and ABS (line 2-c in the fig-
ure).
3. CAN DIAG SUPPORT MNTR (without PAST): Check the CAN DIAG SUPPORT MNTR (without PAST) of
units indicating “U1000” or “U1001” on SELF-DIAG RESULTS. Draw a line on the diagnosis sheet to indi-
cate the possible error circuit.
NOTE:
• While an error occurred in the past according to SELF-DIAG RESULTS, it is unclear which signal is not
received. Assume that errors were detected from all reception items.
• Draw a single line among the unit and all reception items. (Work flow differs from CAN DIAG SUPPORT
MNTR (with PAST).)
a. Reception item of “EPS”: Assume that the unit could not receive the signals from ECM, ABS, and M&A.
Draw a line among EPS, ECM, ABS, and M&A (line 3-a in the figure).
SKIB8732E

TROUBLE DIAGNOSES WORK FLOW
LAN-31
< SERVICE INFORMATION >[CAN FUNDAMENTAL]
C
D
E
F
G
H
I
J
L
MA
B
LAN
N
O
P
b. Reception item of “ABS”: Assume that the unit could not receive the signal from ECM. Draw a line
between ABS and ECM (line 3-b in the figure).
4. Search for the possible cause using CAN communication signal chart using information from the interview
with the customer.
NOTE:
For the details of CAN communication signal, refer to LAN-44, "
CAN Communication Signal Chart".
a. ABS warning lamp turned ON and speedometer did not move: This means that “ABS warning lamp signal”
and “Vehicle speed signal” could not communicate between M&A and ABS (4-a in the figure).
SKIB8733E

LAN-32
< SERVICE INFORMATION >[CAN FUNDAMENTAL]
TROUBLE DIAGNOSES WORK FLOW
b. The tachometer moved normally: This means that “Engine speed signal” could communicate normally
between ECM and M&A (4-b in the figure).
5. Fill out the diagnosis sheet based on information from step 4.
a. The ABS warning lamp turned ON and speedometer did not move: Assume that a possible cause is no
communication between M&A and ABS. Draw a line between M&A and ABS. (Line 5-a in the figure).
SKIB8895E

TROUBLE DIAGNOSES WORK FLOW
LAN-33
< SERVICE INFORMATION >[CAN FUNDAMENTAL]
C
D
E
F
G
H
I
J
L
MA
B
LAN
N
O
P
b. The tachometer moved normally: Put check marks between ECM and M&A. The circuit between ECM and
M&A is functioning properly (check marks 5-b in the figure).
6. The circuit which has the most amount of lines are the possible cause. Error is detected from ABS actua-
tor and electric unit (control unit) branch line (shaded in the figure).
NOTE:
For abbreviations, refer to LAN-37, "
Abbreviation List".
SKIB8735E

LAN-34
< SERVICE INFORMATION >[CAN FUNDAMENTAL]
TROUBLE DIAGNOSES WORK FLOW
7. Perform the inspection procedure for the possible cause. Refer to LAN-61, "Malfunction Area Chart".
Past Error — Short Circuit —
When the symptoms listed below exist, a short circuit of the CAN communication line is a possible cause.
SKIB8896E
Item (CONSULT-II) Indication Inspection procedure
SELF-DIAG RESULTS “U1000” and “U1001” is indicated in the past for most units.
Refer to LAN-61, "
Malfunction
Area Chart".
CAN DIAG SUPPORT MNTROnly on CAN DIAG SUPPORT MNTR (with PAST), “1 - 39” is in-
dicated on “PAST” of “TRANSMIT DIAG” and the reception item.

TROUBLE DIAGNOSES WORK FLOW
LAN-35
< SERVICE INFORMATION >[CAN FUNDAMENTAL]
C
D
E
F
G
H
I
J
L
MA
B
LAN
N
O
P
SKIB8897E

LAN-36
< SERVICE INFORMATION >[CAN]
INDEX FOR DTC
SERVICE INFORMATION
INDEX FOR DTC
DTC No. IndexINFOID:0000000003533619
DTCSelf-diagnosis item
(CONSULT-II indication)DTC detection condition Inspection
U1000 CAN COMM CIRCUITWhen ECM is not transmitting or receiving CAN
communication signal of OBD (emission-related
diagnosis) for 2 seconds or more.
Refer to LAN-37
. When a control unit (except for ECM) is not
transmitting or receiving CAN communication
signal for 2 seconds or more.
U1001 CAN COMM CIRCUITWhen ECM is not transmitting or receiving CAN
communication signal other than OBD (emis-
sion-related diagnosis) for 2 seconds or more.
U1002 SYSTEM COMMWhen a control unit is not transmitting or receiv-
ing CAN communication signal for 2 seconds or
less.Start the inspection. Re-
fer to the applicable sec-
tion of the indicated
control unit.
U1010 CONTROL UNIT [CAN]When an error is detected during the initial diag-
nosis for CAN controller of each control unit.Replace the control unit
indicating “U1010”.

HOW TO USE THIS SECTION
LAN-37
< SERVICE INFORMATION >[CAN]
C
D
E
F
G
H
I
J
L
MA
B
LAN
N
O
P
HOW TO USE THIS SECTION
CautionINFOID:0000000003533620
• This section describes information peculiar to a vehicle, sheets for trouble diagnosis, and inspection proce-
dures.
• For trouble diagnosis procedure, refer to LAN-14, "
Trouble Diagnosis Procedure".
Abbreviation ListINFOID:0000000003533621
Abbreviations in CAN communication signal chart, and the diagnosis sheet are as per the following list.
Abbreviation Unit nameSELECT SYSTEM
(CONSULT-II)CAN DIAG SUPPORT MNTR
(CONSULT-II)
4WD Transfer control unit ALL MODE AWD/4WD AWD/4WD
A-BAG Air bag diagnosis sensor unit AIR BAG –
ABS ABS actuator and electric unit (control unit) ABS VDC/TCS/ABS
ADP Driver seat control unit AUTO DRIVE POS. –
BCM BCM BCM BCM/SEC
DISP Display control unit – DISPLAY
DLC Data link connector – –
ECM ECM ENGINE ECM
HVAC Front air control HVAC –
ICC ICC unit ICCICC
ICC/e4WD
IPDM-E IPDM E/R IPDM E/R IPDM E/R
LASER ICC sensor – ICC SENSOR
M&A Combination meter – METER/M&A
STRG Steering angle sensor – STRG
TCM A/T assembly A/T TCM