2007 INFINITI QX56 ignition

PRECAUTIONS
LAN-3
< SERVICE INFORMATION >[CAN FUNDAMENTAL]
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SERVICE INFORMATION
PRECAUTIONS
Precaution When Using CONSULT-IIINFOID:0000000003533606
Use CONSULT-II CONVERTER when connecting CONSULT-II to data link connector.
CAUTION:
CAN communication does not function properly if CONSULT-II is used without connecting CONSULT-II
CONVERTER.
Precaution for Trouble DiagnosisINFOID:0000000003533607
CAUTION:
• Never apply 7.0 V or more to the measurement terminal.
• Use a tester with open terminal voltage of 7.0 V or less.
• Turn the ignition switch OFF and disconnect the battery cable from the negative terminal when
checking the harness.
Precaution for Harness RepairINFOID:0000000003533608
• Solder the repaired area and wrap tape around the soldered area.
NOTE:
A fray of twisted lines must be within 110 mm (4.33 in).
• Bypass connection is never allowed at the repaired area.
NOTE:
Bypass connection may cause CAN communication error. The
spliced wire becomes separated and the characteristics of twisted
line are lost.
• Replace the applicable harness as an assembly if error is detected on the shield lines of CAN communica-
tion line.
SKIB8766E
SKIB8767E

TROUBLE DIAGNOSIS
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< SERVICE INFORMATION >[CAN FUNDAMENTAL]
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TROUBLE DIAGNOSIS
Condition of Error DetectionINFOID:0000000003533611
“U1000” or “U1001” is indicated on SELF-DIAG RESULTS on CONSULT-II if CAN communication signal is not
transmitted or received between units for 2 seconds or more.
CAN COMMUNICATION SYSTEM ERROR
• CAN communication line open (CAN-H, CAN-L, or both)
• CAN communication line short (ground, between CAN communication lines, other harnesses)
• Error of CAN communication control circuit of the unit connected to CAN communication line
WHEN INDICATED “U1000” OR “U1001” IS INDICATED EVEN THOUGH CAN COMMUNICATION
SYSTEM IS NORMAL
• CONSULT-II CONVERTER not connected: Error may be detected by the self-diagnosis when not using
CONSULT-II CONVERTER (Depending on the control unit which carries out CAN communication).
• Removal/installation of parts: Error may be detected when removing and installing CAN communication unit
and related parts while turning the ignition switch ON. (A DTC except for CAN communication may be
detected.)
• Fuse blown out (removed): CAN communication of the unit may cease.
• Voltage drop: Error may be detected if voltage drops due to discharged battery when turning the ignition
switch ON (Depending on the control unit which carries out CAN communication).
• Error may be detected if the power supply circuit of the control unit, which carries out CAN communication,
malfunctions (Depending on the control unit which carries out CAN communication).
• Error may be detected if reprogramming is not completed normally.
NOTE:
CAN communication system is normal if “U1000” or “U1001” is indicated on SELF-DIAG RESULTS of CON-
SULT-II under the above conditions. Erase the memory of the self-diagnosis of each unit.
Symptom When Error Occurs in CAN Communication SystemINFOID:0000000003533612
In CAN communication system, multiple units mutually transmit and receive signals. Each unit cannot transmit
and receive signals if any error occurs on CAN communication line. Under this condition, multiple control units
related to the root cause malfunction or go into fail-safe mode.
ERROR EXAMPLE
NOTE:
• Each vehicle differs in symptom of each unit under fail-safe mode and CAN communication line wiring.
• Refer to LAN-37, "
Abbreviation List" for the unit abbreviation.
Example: TCM branch line open circuit
SKIB8738E

TROUBLE DIAGNOSIS
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< SERVICE INFORMATION >[CAN FUNDAMENTAL]
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P Example: Main Line Between Data Link Connector and ABS Actuator and Electric Unit (Control Unit) Open Circuit
Example: CAN-H, CAN-L Harness Short Circuit
SKIB8740E
Unit name Symptom
ECM Engine torque limiting is affected, and shift harshness increases.
BCM• Reverse warning chime does not sound.
• The front wiper moves under continuous operation mode even though the front wip-
er switch being in the intermittent position.
EPS control unit The steering effort increases.
Combination meter• The shift position indicator and OD OFF indicator turn OFF.
• The speedometer is inoperative.
• The odo/trip meter stops.
ABS actuator and electric unit (control unit) Normal operation.
TCM No impact on operation.
IPDM E/RWhen the ignition switch is ON,
• The headlamps (Lo) turn ON.
• The cooling fan continues to rotate.
SKIB8741E

LAN-10
< SERVICE INFORMATION >[CAN FUNDAMENTAL]
TROUBLE DIAGNOSIS
Self-Diagnosis
INFOID:0000000003533613
CAN Diagnostic Support MonitorINFOID:0000000003533614
CONSULT-II and CAN diagnostic support monitor (on-board diagnosis function) are used for detecting root
cause.
MONITOR ITEM (CONSULT-II)
Unit name Symptom
ECM• Engine torque limiting is affected, and shift harshness increases.
• Engine speed drops.
BCM• Reverse warning chime does not sound.
• The front wiper moves under continuous operation mode even though the front
wiper switch being in the intermittent position.
• The room lamp does not turn ON.
• The engine does not start (if an error or malfunction occurs while turning the igni-
tion switch is OFF.)
• The steering lock does not release (if an error or malfunction occurs while turning
the ignition switch is OFF.)
EPS control unit The steering effort increases.
Combination meter• The tachometer and the speedometer do not move.
• Warning lamps turn ON.
• Indicator lamps do not turn ON.
ABS actuator and electric unit (control unit) Normal operation.
TCM No impact on operation.
IPDM E/RWhen the ignition switch is ON,
• The headlamps (Lo) turn ON.
• The cooling fan continues to rotate.
DTCSelf-diagnosis item
(CONSULT-II indication)DTC detection condition Inspection/Action
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-13
. 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”.

TROUBLE DIAGNOSIS
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< 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)

TROUBLE DIAGNOSES WORK FLOW
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< SERVICE INFORMATION >[CAN FUNDAMENTAL]
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• Result: Symptom
NOTE:
• Check normal units as well as error symptoms.
- Example: Circuit between ECM and the combination meter is judged normal if the customer indicates
tachometer functions normally.
• When a CAN communication system error is present, multiple control units may malfunction or go into fail-
safe mode.
• Indication of the combination meter is important to detect the root cause because it is the most obvious from
the customer, and it performs CAN communication with many units.
INSPECTION OF VEHICLE CONDITION
• Check whether or not “U1000” or “U1001” is indicated on “SELF-DIAG RESULTS” by CONSULT-II.
NOTE:
Root cause cannot be detected using the procedure in this section if “U1000” or “U1001” is not indicated.
• Check whether the symptom is reproduced or not.
NOTE:
• Never turn the ignition switch OFF or disconnect the battery cable while the reproducing the error. The
error may temporarily correct itself, making it difficult to determine the root cause.
• The procedures for present errors differ from the procedures for past errors. Refer to "DETECT THE
ROOT CAUSE".
CHECK OF CAN SYSTEM TYPE (HOW TO USE CAN SYSTEM TYPE SPECIFICATION CHART)
Determine CAN system type based on vehicle equipment. Then choose the correct diagnosis sheet.
NOTE:
There are two styles for CAN system type specification charts. Depending on the number of available system
types, either style A or style B may be used.
CAN System Type Specification Chart (Style A)
NOTE:
SKIB8717E

LAN-38
< SERVICE INFORMATION >[CAN]
PRECAUTIONS
PRECAUTIONS
Precaution for Supplemental Restraint System (SRS) "AIR BAG" and "SEAT BELT
PRE-TENSIONER"
INFOID:0000000003533622
The Supplemental Restraint System such as “AIR BAG” and “SEAT BELT PRE-TENSIONER”, used along
with a front seat belt, helps to reduce the risk or severity of injury to the driver and front passenger for certain
types of collision. This system includes seat belt switch inputs and dual stage front air bag modules. The SRS
system uses the seat belt switches to determine the front air bag deployment, and may only deploy one front
air bag, depending on the severity of a collision and whether the front occupants are belted or unbelted.
Information necessary to service the system safely is included in the SRS and SB section of this Service Man-
ual.
WARNING:
• To avoid rendering the SRS inoperative, which could increase the risk of personal injury or death in
the event of a collision which would result in air bag inflation, all maintenance must be performed by
an authorized NISSAN/INFINITI dealer.
• Improper maintenance, including incorrect removal and installation of the SRS, can lead to personal
injury caused by unintentional activation of the system. For removal of Spiral Cable and Air Bag
Module, see the SRS section.
• Do not use electrical test equipment on any circuit related to the SRS unless instructed to in this
Service Manual. SRS wiring harnesses can be identified by yellow and/or orange harnesses or har-
ness connectors.
Precaution When Using CONSULT-IIINFOID:0000000003533623
Use CONSULT-II CONVERTER when connecting CONSULT-II to data link connector.
CAUTION:
CAN communication does not function properly if CONSULT-II is used without connecting CONSULT-II
CONVERTER.
Precaution for Trouble DiagnosisINFOID:0000000003533624
CAUTION:
• Never apply 7.0 V or more to the measurement terminal.
• Use a tester with open terminal voltage of 7.0 V or less.
• Turn the ignition switch OFF and disconnect the battery cable from the negative terminal when
checking the harness.
Precaution for Harness RepairINFOID:0000000003533625
• Solder the repaired area and wrap tape around the soldered area.
NOTE:
A fray of twisted lines must be within 110 mm (4.33 in).
SKIB8766E

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