warning INFINITI QX56 2007 Factory Service Manual

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-9
< 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 DIAGNOSES WORK FLOW
LAN-31
< SERVICE INFORMATION >[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).
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

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

TROUBLE DIAGNOSIS
LAN-45
< SERVICE INFORMATION >[CAN]
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Engine speed signal T R R R R R R
Engine status signal T R
Fuel consumption monitor signalTR
RT
ICC steering switch signal T R
Malfunction indicator lamp signal T R
Wide open throttle position signal T R
A/T CHECK indicator lamp signal T R
A/T fluid temperature sensor signal T R
A/T position indicator lamp signal T R R
A/T self-diagnosis signal R T
Current gear position signal T R R
Output shaft revolution signal R T R
P range signal T R R R R
Turbine revolution signal R T R
ICC sensor signal T R
Buzzer output signalTR
TR
ICC OD cancel request signal R R T
ICC operation signal R R T
ICC system display signal T R
System setting signalTR
RT
A/C switch signal R T R
Blower fan motor switch signal R T
Day time running light request signal T R R
Door switch signal R T R R R
Front fog light request signal T R
Front wiper request signal R T R
High beam request signal T R R
Horn chirp signal T R
Ignition switch signal R T R
Key fob door unlock signal R T
Key fob ID signal R T
Key switch signal R T
Low beam request signal T R
Position light request signal T R R
Rear window defogger switch signal T R R
Sleep wake up signal R T R R
Theft warning horn request signal T R
Tire pressure data signal T R
Tire pressure signal T R R
Turn indicator signal T RSignal name/Connecting unit
ECM
TCM
LASER
ICC
ADP
BCM
DISP
HVAC
M&A
STRG
ABS
IPDM-E

LAN-46
< SERVICE INFORMATION >[CAN]
TROUBLE DIAGNOSIS
NOTE:
CAN data of the air bag diagnosis sensor unit is not used by usual service work, thus it is omitted.
TYPE 3/TYPE 4
NOTE:
Refer to LAN-37, "
Abbreviation List" for the abbreviations of the connecting units.
T: Transmit R: Receive
A/C switch/indicator signalTR
RT
1st position switch signal R T
4th position switch signal R T
Distance to empty signal R T
Fuel level low warning signal R T
Fuel level sensor signal R T
Parking brake switch signal R T
Stop lamp switch signal R T
Tow mode switch signal R T
Vehicle speed signalRR T
RRR RRR T
Steering angle sensor signalTR
ABS malfunction signal R T
ABS warning lamp signalRT
Brake pressure sensor signal R T
Brake warning lamp signalRT
SLIP indicator lamp signalRT
TCS malfunction signal R T
VDC malfunction signal R T
VDC OFF indicator lamp signal R R T
VDC operation signal R T
Front wiper stop position signal R T
High beam status signal RT
Hood switch signal R T
Low beam status signal RT
Rear window defogger control signal R R TSignal name/Connecting unit
ECM
TCM
LASER
ICC
ADP
BCM
DISP
HVAC
M&A
STRG
ABS
IPDM-E
Signal name/Connecting unitECM
TCM
LASER
ICC
ADP
BCM
DISP
HVAC
M&A
STRG
4WD
ABS
IPDM-E
A/C compressor request signal TR
Accelerator pedal position signal T R R R R
ASCD CRUISE lamp signal T R
ASCD OD cancel request signal T R
ASCD operation signal T R
ASCD SET lamp signal T R
Battery voltage signal T R
Closed throttle position signal T R R

TROUBLE DIAGNOSIS
LAN-47
< SERVICE INFORMATION >[CAN]
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Cooling fan speed request signal TR
Engine coolant temperature signal T R R
Engine speed signal T R R R R R R R
Engine status signal T R
Fuel consumption monitor signalTR
RT
ICC steering switch signal T R
Malfunction indicator lamp signal T R
Wide open throttle position signal T R
A/T CHECK indicator lamp signal T R
A/T fluid temperature sensor signal T R
A/T position indicator lamp signal T R R R
A/T self-diagnosis signal R T
Current gear position signal T R R
Output shaft revolution signal R T R R
P range signal T R R R R
Turbine revolution signal R T R
ICC sensor signal T R
Buzzer output signalTR
TR
ICC OD cancel request signal R R T
ICC operation signal R R T
ICC system display signal T R
System setting signalTR
RT
A/C switch signal R T R
Blower fan motor switch signal R T
Day time running light request signal T R R
Door switch signal R T R R R
Front fog light request signal T R
Front wiper request signal R T R
High beam request signal T R R
Horn chirp signal T R
Ignition switch signal R T R
Key fob door unlock signal R T
Key fob ID signal R T
Key switch signal R T
Low beam request signal T R
Position light request signal T R R
Rear window defogger switch signal T R R
Sleep wake up signal R T R R
Theft warning horn request signal T R
Tire pressure data signal T RSignal name/Connecting unit
ECM
TCM
LASER
ICC
ADP
BCM
DISP
HVAC
M&A
STRG
4WD
ABS
IPDM-E

LAN-48
< SERVICE INFORMATION >[CAN]
TROUBLE DIAGNOSIS
NOTE:
CAN data of the air bag diagnosis sensor unit is not used by usual service work, thus it is omitted.
Tire pressure signal T R R
Turn indicator signal T R
A/C switch/indicator signalTR
RT
1st position switch signal R T
4th position switch signal R T
Distance to empty signal R T
Fuel level low warning signal R T
Fuel level sensor signal R T
Parking brake switch signal R T
Stop lamp switch signal R T
Tow mode switch signal R T
Vehicle speed signalRR R T
RRR RRR T
Steering angle sensor signalTR
ABS malfunction signal R T
ABS warning lamp signalRT
Brake pressure sensor signal R T
Brake warning lamp signalRT
SLIP indicator lamp signalRT
TCS malfunction signal R T
VDC malfunction signal R T
VDC OFF indicator lamp signal R R T
VDC operation signal R T
Front wiper stop position signal R T
High beam status signal RT
Hood switch signal R T
Low beam status signal RT
Rear window defogger control signal R R TSignal name/Connecting unit
ECM
TCM
LASER
ICC
ADP
BCM
DISP
HVAC
M&A
STRG
4WD
ABS
IPDM-E