2008 INFINITI QX56 warning

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TROUBLE DIAGNOSISLAN-7
< FUNCTION DIAGNOSIS > [CAN FUNDAMENTAL]
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TROUBLE DIAGNOSIS
Condition of Error DetectionINFOID:0000000001374966
“U1000” or “U1001” is indicated on SELF-DIAG RESULTS on CONSULT-III 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, betw
een CAN communication lines, other harnesses)
• Error of CAN communication control circuit of the unit connected to CAN communication line
WHEN “U1000” OR “U1001” IS INDICATED EV EN THOUGH CAN COMMUNICATION SYSTEM IS
NORMAL
• Removal/installation of parts: Error may be detec ted 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 “U 1001” is indicated on SELF-DIAG RESULTS of CON-
SULT-III under the above conditions. Erase the memory of the self-diagnosis of each unit.
Symptom When Error Occurs in CAN Communication SystemINFOID:0000000001374967
In CAN communication system, multiple units mutually transmit and receive signals. Each unit cannot transmit
and receive signals if any error occurs on CAN communicati on 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-36, "
Abbreviation List" for the unit abbreviation.
Example: TCM branch line open circuit
SKIB8738E
Unit name Symptom
ECM Engine torque limiting is affected, and shift harshness increases.
BCM Reverse warning chime does not sound.
Revision: March 2010 2008 QX56

LAN-8
< FUNCTION DIAGNOSIS >[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
are not affected. Therefore, no symptoms occur. However, be sure to repair malfunctioning circuit.
• When data link connector branch line is open, “ECU list” displayed on the CONSULT-III “CAN DIAG SUP- PORT MNTR” may be the same as when the CAN communication line has short-circuit. However, symp-
toms differ depending on the case. See below chart for the differences.
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.
Unit name
Symptom
SKIB8739E
Unit nameSymptom
ECM
Normal operation.
BCM
EPS control unit
Combination meter
ABS actuator and electric unit (control unit)
TCM
IPDM E/R
“ECU list” on the “CAN DIAG SUPPORT MNTR”(CONSULT-III) 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-circuit Most of the units which are connected to the CAN
communication system enter fail-safe mode or are
deactivated.
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2008 QX56

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TROUBLE DIAGNOSISLAN-9
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Example: Main Line Between Data Link Connector and ABS Actuator and Electr
ic 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/R When the ignition switch is ON,
• The headlamps (Lo) turn ON.
• The cooling fan continues to rotate.
SKIB8741E
Revision: March 2010
2008 QX56

LAN-10
< FUNCTION DIAGNOSIS >[CAN FUNDAMENTAL]
TROUBLE DIAGNOSIS
Self-Diagnosis
INFOID:0000000001374968
CAN Diagnostic Support MonitorINFOID:0000000001374969
CONSULT-III and CAN diagnostic support monitor (on-boar d diagnosis function) are used for detecting root
cause.
MONITOR ITEM (CONSULT-III)
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 OFF.)
• The steering lock does not release (if an error or malfunction occurs while turning the ignition switch 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/R When the ignition switch is ON,
• The headlamps (Lo) turn ON.
• The cooling fan continues to rotate.
DTC
Self-diagnosis item
(CONSULT-III indication) DTC detection condition
Inspection/Action
U1000 CAN COMM CIRCUIT When 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 CIRCUIT When ECM is not transmitting or receiving CAN
communication signal other than OBD (emis-
sion-related diagnosis) for 2 seconds or more.
U1002 SYSTEM COMM When 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”.
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DIAGNOSIS AND REPAIR WORKFLOWLAN-31
< BASIC INSPECTION > [CAN FUNDAMENTAL]
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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 below).
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 below).
PKID1223E
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LAN-32
< BASIC INSPECTION >[CAN FUNDAMENTAL]
DIAGNOSIS AND REPAIR WORKFLOW
b. The tachometer moved normally: This means that “Engine speed signal” could communicate normally
between ECM and M&A (4-b in the figure below).
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
below).
SKIB8895E
Revision: March 2010 2008 QX56

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PRECAUTIONSLAN-37
< PRECAUTION > [CAN]
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PRECAUTION
PRECAUTIONS
Precaution for Supplemental
Restraint System (SRS) "AIR BAG" and "SEAT BELT
PRE-TENSIONER"
INFOID:0000000004832404
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 severi ty 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 w hether the front occupants are belted or unbelted.
Information necessary to service the system safely is included in the SR and SB section of this Service Man-
ual.
WARNING:
• To avoid rendering the SRS inoper ative, 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 in correct removal and installation of the SRS, can lead to personal
injury caused by unintentional act ivation of the system. For removal of Spiral Cable and Air Bag
Module, see the SR section.
• Do not use electrical test equipm ent on any circuit related to the SRS unless instructed to in this
Service Manual. SRS wiring harnesses can be identi fied by yellow and/or orange harnesses or har-
ness connectors.
PRECAUTIONS WHEN USING POWER TOOLS (AIR OR ELECTRIC) AND HAMMERS
WARNING:
• When working near the Airbag Diagnosis Sensor Un it or other Airbag System sensors with the Igni-
tion ON or engine running, DO NOT use air or el ectric power tools or strike near the sensor(s) with a
hammer. Heavy vibration could activate the sensor( s) and deploy the air bag(s), possibly causing
serious injury.
• When using air or electric power tools or hammers, always switch the Ignition OFF, disconnect the battery, and wait at least 3 minutes before performing any service.
Precautions for Trouble DiagnosisINFOID:0000000001282381
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 th e battery cable from the negative terminal when
checking the harness.
Precautions for Harness RepairINFOID:0000000001282382
• 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
Revision: March 2010 2008 QX56

LAN
CAN COMMUNICATION SYSTEMLAN-45
< FUNCTION DIAGNOSIS > [CAN]
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Engine speed signal
T RRR R R R R R
Engine status signal TR
Fuel consumption monitor signal TR
RT
ICC steering switch signal TR
Malfunction indicator lamp signal T R
Wide open throttle position signal T R
A/T CHECK indicato r lamp signal T R
A/T fluid temperature sensor signal T R
A/T position indicator lamp signal TR RR
A/T self-diagnosis signal R T
Current gear position signal TR R
Input speed signal R TR
Output shaft revolution signal R TR R
P range signal TR R RR
ICC sensor signal T R
Buzzer output signal TR
TR
ICC OD cancel request signal R RT
ICC operation signal R RT
ICC system display signal TR
System setting signal TRT
RTR
A/C switch/indicator signal TR
RT
A/C switch signal RT R
Blower fan motor switch signal RT
Day time running light request signal TR R
Door lock/unlock status signal TR
Door switch signal R R TR R R
Front fog light request signal TR
Front wiper request signal RT R
High beam request signal TR R
Horn chirp signal TR
Ignition switch signal RTR R
Key fob door unlock signal RT
Key fob ID signal RT
Key switch signal RT
Low beam request signal TR
Position light request signal TR R
Rear window defogger switch signal T RR
Sleep wake up signal RT R R
Theft warning horn request signal TR
Signal name/Connecting unit
ECM
TCM
LASER ICC
ADP AV
BCM
HVAC I-KEY M&A
STRG 4WD
ABS
IPDM-E
Revision: March 2010 2008 QX56