2007 INFINITI QX56 transmission

LAN-8
< SERVICE INFORMATION >[CAN FUNDAMENTAL]
TROUBLE DIAGNOSIS
Example: Data link connector branch line open circuit
NOTE:
• When data link connector branch line is open, transmission and reception of CAN communication signals is
not affected. Therefore, no symptoms occur. However, be sure to repair malfunctioning circuit.
• When data link connector branch line is open, the screen-display of the CONSULT-II “SELECT SYSTEM”
screen may be the same as when the CAN communication line has short-circuit. However, symptoms differ
depending on the case. See below chart for the differences.
Unit name Symptom
ECM Engine torque limiting is affected, and shift harshness increases.
BCM Reverse warning chime does not sound.
EPS control unit Normal operation.
Combination meter• Shift position indicator and OD OFF indicator turn OFF.
• Warning lamps turn ON.
ABS actuator and electric unit (control unit) Normal operation.
TCM No impact on operation.
IPDM E/R Normal operation.
SKIB8739E
Unit name Symptom
ECM
Normal operation. BCM
EPS control unit
Combination meter
ABS actuator and electric unit (control unit)
TCM
IPDM E/R
SELECT SYSTEM
(CONSULT-II)Difference of symptom
Data link connector branch line open circuit
All Diag on CAN units are not
indicated.Normal operation.
CAN-H, CAN-L harness short-circuitMost the units which are connected to the CAN com-
munication system enter fail-safe mode or are deac-
tivated.

TROUBLE DIAGNOSIS
LAN-11
< SERVICE INFORMATION >[CAN FUNDAMENTAL]
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Example: CAN DIAG SUPPORT MNTR indication
Without PAST
With PAST
MONITOR ITEM (ON-BOARD DIAGNOSIS)
NOTE:
• For some models, CAN communication diagnosis result is received from the vehicle monitor. (CONSULT-II
is not available.)
• Refer to LAN-40, "
CAN Diagnostic Support Monitor" for the details.
SKIB8742E
Item PRSNT Description
Initial diagnosisOK Normal at present
NG Control unit error (Except for some control units)
Transmission diagnosisOK Normal at present
UNKWNUnable to transmit signals for 2 seconds or more.
Diagnosis not performed
Control unit name
(Reception diagnosis)OK Normal at present
UNKWNUnable to receive signals for 2 seconds or more.
Diagnosis not performed
No control unit for receiving signals. (No applicable optional parts)
Item PRSNT PAST Description
Transmission diagnosisOKOK Normal at present and in the past
1 – 39Normal at present, but unable to transmit signals for 2 seconds or more
in the past. (The number indicates the number of ignition switch cycles
from OFF to ON.)
UNKWN 0 Unable to transmit signals for 2 seconds or more at present.
Control unit name
(Reception diagnosis)OKOK Normal at present and in the past
1 – 39Normal at present, but unable to receive signals for 2 seconds or more
in the past. (The number indicates the number of ignition switch cycles
from OFF to ON.)
UNKWN 0 Unable to receive signals for 2 seconds or more at present
––Diagnosis not performed.
No control unit for receiving signals. (No applicable optional parts)

LAN-12
< SERVICE INFORMATION >[CAN FUNDAMENTAL]
TROUBLE DIAGNOSIS
Example: Vehicle Display
ItemResult indi-
catedError counter Description
CAN_COMM
(Initial diagnosis)OK 0 Normal at present
NG 1 – 50Control unit error
(The number indicates how many times diagnosis has been
run.)
CAN_CIRC_1
(Transmission diagnosis)OK 0 Normal at present
UNKWN 1 – 50Unable to transmit for 2 seconds or more at present.
(The number indicates how many times diagnosis has been
run.)
CAN_CIRC_2 – 9
(Reception diagnosis of each unit)OK 0 Normal at present
UNKWN 1 – 50Unable to transmit for 2 seconds or more at present.
(The number indicates how many times diagnosis has been
run.)
Diagnosis not performed.
No control unit for receiving signals. (No applicable optional
parts)

TROUBLE DIAGNOSES WORK FLOW
LAN-13
< SERVICE INFORMATION >[CAN FUNDAMENTAL]
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TROUBLE DIAGNOSES WORK FLOW
Information Needed for Trouble DiagnosisINFOID:0000000003533615
CAN communication system performs trouble diagnosis with the following tools.
How to Use CAN Communication Signal ChartINFOID:0000000003533616
The CAN communication signal chart lists the signals needed for trouble diagnosis. It is useful for detecting
the root cause by finding a signal related to the symptom, and by checking transmission and reception unit.
To o l U s a g e
Interview sheet For filling in vehicle information and interview with customer.
Data sheet For attaching CONSULT-II data or on-board diagnosis data.
Diagnosis sheet For detecting the root cause. (Diagnosis sheet includes system diagram for every CAN system type)
SELECT SYSTEM
(CONSULT-II)
For checking the condition of control units and the status of CAN communication. SELF-DIAG RESULTS
(CONSULT-II)
CAN DIAG SUPPORT MNTR
(CONSULT-II)
CAN communication signal
chartFor converting information received from a customer into CAN communication signal transmission
and reception. This information can be used to judge whether a circuit between control units is nor-
mal or abnormal.
Abbreviation list For checking abbreviations in CAN communication signal chart and diagnosis sheet.
SKIB8715E

TROUBLE DIAGNOSES WORK FLOW
LAN-21
< SERVICE INFORMATION >[CAN FUNDAMENTAL]
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• For abbreviations, refer to LAN-37, "Abbreviation List".
DETECT THE ROOT CAUSE
Identify the root cause using the created diagnosis sheet.
Identifying the root cause• Draw a line on the diagnosis sheet to indicate the possible cause. Narrow the search.
NOTE:
• Color-code when drawing lines.
• Do not draw a line onto a existing line.
• Drawing a line is not necessary if the circuit is shorted. Refer to "Present Error — Short Circuit —", "Past
Error — Short Circuit —".
Refer to the following for details of the trouble diagnosis procedure.
• "Present Error — Open Circuit —"
• "Present Error — Short Circuit —"
• "Past Error — Open Circuit —"
• "Past Error — Short Circuit —"
NOTE:
When the root cause appears to be a branch line or short circuit, be sure to check the control unit as well as
the communication line.
Present Error — Open Circuit —
Identify the error circuit using information from the “SELECT SYSTEM” and “CAN DIAG SUPPORT MNTR”
screens.
1. SELECT SYSTEM: Check the items indicated in “SELECT SYSTEM”. Draw a line on the diagnosis sheet
to indicate the error circuit.
NOTE:
CAN communication line has no error if units other than Diag on CAN units are indicated. An error may be
on the power supply of the control unit, DDL1 line or DDL2 line.
a. “TRANSMISSION” which is Diag on CAN unit, is not indicated on “SELECT SYSTEM” screen. This indi-
cates that DLC is not receiving a signal from TCM. Draw a line to indicate an error between DLC and TCM
(line 1-a in the figure).
NOTE:
• Diag on CAN units are not indicated on the “SELECT SYSTEM” screen when the CAN line between
Diag on CAN unit and the data link connector is open.
SKIB8891E

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

LAN-40
< SERVICE INFORMATION >[CAN]
TROUBLE DIAGNOSIS
TROUBLE DIAGNOSIS
CAN Diagnostic Support MonitorINFOID:0000000003533626
Use “CAN DIAG SUPPORT MNTR” for detecting the root cause.
MONITOR ITEM LIST (CONSULT-II)
ECM
0: Error at present, 1 – 39: Error in the past (Number means the number of times the ignition switch is turned OFF→ON)
*: 39 or higher number is fixed at 39 until the self-diagnosis result is erased.
TCM
NOTE:
Replace the unit when “NG” is indicated on the “INITIAL DIAG”.
ICC Unit
NOTE:
Replace the unit when “NG” is indicated on the “INITIAL DIAG”.
SELECT SYS-
TEMCAN DIAG SUP-
PORT MNTRDescriptionNormal Error
PRSNT PAST PRSNT PAST
ENGINETRANSMIT DIAG Signal transmission status
OKOK
or
1 – 39
*UNKWN 0 VDC/TCS/ABSSignal receiving status from the ABS actu-
ator and electric unit (control unit)
METER/M&ASignal receiving status from the combina-
tion meter
BCM/SEC Signal receiving status from the BCM
ICC Signal receiving status from the ICC unit
HVAC Not used even though indicated
TCM Signal receiving status from the TCM OKOK
or
1 – 39
*UNKWN 0
EPS Not used even though indicated
IPDM E/R Signal receiving status from the IPDM E/R OKOK
or
1 – 39
*UNKWN 0
e4WD Not used even though indicated
AWD/4WDSignal receiving status from the transfer
control unitOKOK
or
1 – 39
*UNKWN 0
SELECT SYS-
TEMCAN DIAG SUP-
PORT MNTRDescriptionNormal Error
PRSNT
A/TINITIAL DIAG Status of CAN controller
OKNG
TRANSMIT DIAG Signal transmission status
UNKWN ECM Signal receiving status from the ECM
VDC/TCS/ABSSignal receiving status from the ABS actuator and electric unit
(control unit)
METER/M&A Signal receiving status from the combination meter
ICC/e4WD Signal receiving status from the ICC unit
AWD/4WD Signal receiving status from the transfer control unit

TROUBLE DIAGNOSIS
LAN-41
< SERVICE INFORMATION >[CAN]
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0: Error at present, 1 – 39: Error in the past (Number means the number of times the ignition switch is turned OFF→ON)
*: 39 or higher number is fixed at 39 until the self-diagnosis result is erased.
BCM
NOTE:
Replace the unit when “NG” is indicated on the “INITIAL DIAG”.
Front Air Control
SELECT SYS-
TEMCAN DIAG SUP-
PORT MNTRDescriptionNormal Error
PRSNT
ICCINITIAL DIAG Status of CAN controller
OKNG
TRANSMIT DIAG Signal transmission status
UNKWN ECM Signal receiving status from the ECM
VDC/TCS/ABSSignal receiving status from the ABS actuator and electric unit
(control unit)
TCM Signal receiving status from the TCM
METER/M&A
Not used even though indicated LANE KEEP
ECM(l)
ICC SENSOR Signal receiving status from the ICC sensor OK UNKWN
STRG
Not used even though indicated METER/M&A(l)
ERROR(l)
LANE DETEC-
TOR
TCM(l)
BCM/SEC Signal receiving status from the BCM OK UNKWN
SELECT SYS-
TEMCAN DIAG SUP-
PORT MNTRDescriptionNormal Error
PRSNT PAST PRSNT PAST
AUTO DRIVE
POS.TRANSMIT DIAG Not used even though indicated
METER/M&ASignal receiving status from the combina-
tion meter
OKOK
or
1 – 39
*UNKWN 0
BCM/SEC Signal receiving status from the BCM
TCM Signal receiving status from the TCM
SELECT SYS-
TEMCAN DIAG SUP-
PORT MNTRDescriptionNormal Error
PRSNT
BCMINITIAL DIAG Status of CAN controller
OKNG
TRANSMIT DIAG Signal transmission status
UNKWN ECM Signal receiving status from the ECM
IPDM E/R Signal receiving status from the IPDM E/R
METER/M&A Signal receiving status from the combination meter
I-KEY Not used even though indicated