INFINITI QX56 2008 Factory Service Manual

STR-2
< PRECAUTION >
PRECAUTIONS
PRECAUTION
PRECAUTIONS
Precaution for Supplemental Restraint System (SRS) "AIR BAG" and "SEAT BELT
PRE-TENSIONER"
INFOID:0000000004857581
The Supplemental Restraint System such as “A IR 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 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 inopera tive, 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 unintent ional activation of the system. For re moval of Spiral Cable and Air Bag
Module, see the SR section.
• Do not use electrical test equipmen t on any circuit related to the SRS unless instructed to in this
Service Manual. SRS wiring harn esses can be identified 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 Unit or other Airbag System sensors with the Igni-
tion ON or engine running, DO NOT use air or electri c 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 minu tes before performing any service.
Precaution Necessary for Steering W heel Rotation After Battery Disconnect
INFOID:0000000004857584
NOTE:
• This Procedure is applied only to models with Intelligent Key system and NATS (NISSAN ANTI-THEFT SYS-
TEM).
• Remove and install all control units after disconnecting both battery cables with the ignition knob in the
″LOCK ″ position.
• Always use CONSULT-III to perform self-diagnosis as a part of each function inspection after finishing work.
If DTC is detected, perform trouble diagnosis according to self-diagnostic results.
For models equipped with the Intelligent Key system and NATS, an electrically controlled steering lock mech-
anism is adopted on the key cylinder.
For this reason, if the battery is disconnected or if the battery is discharged, the steering wheel will lock and
steering wheel rotation will become impossible.
If steering wheel rotation is required when battery pow er is interrupted, follow the procedure below before
starting the repair operation.
OPERATION PROCEDURE
1. Connect both battery cables. NOTE:
Supply power using jumper cables if battery is discharged.
2. Use the Intelligent Key or mechanical key to turn the ignition switch to the ″ACC ″ position. At this time, the
steering lock will be released.
3. Disconnect both battery cables. The steering lock will remain released and the steering wheel can be rotated.
4. Perform the necessary repair operation.
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PRECAUTIONSSTR-3
< PRECAUTION >
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5. When the repair work is completed, return the ignition switch to the
″LOCK ″ position before connecting
the battery cables. (At this time, the steering lock mechanism will engage.)
6. Perform a self-diagnosis check of al l control units using CONSULT-III.
Precaution for Power Generation Variable Voltage Control SystemINFOID:0000000001538874
CAUTION:
For this model, the battery current sensor that is installed to the negative battery cable measures the
charging/discharging current of the battery and performs various engine controls. If an electrical com-
ponent is connected directly to the negative battery terminal, the current flowing through that compo-
nent will not be measured by the battery current sensor. This condition may cause a malfunction of
the engine control system and battery discharge m ay occur. Do not connect an electrical component
or ground wire directly to the battery terminal.
Revision: March 2010 2008 QX56

STR-4
< PREPARATION >
PREPARATION
PREPARATION
PREPARATION
Special Service ToolINFOID:0000000001538875
The actual shapes of Kent-Moore tools may differ from those of special service tools illustrated here.
Commercial Service ToolINFOID:0000000001538876
Tool number
(Kent-Moore No.)
Tool name Description
—
(J-48087)
Battery Service Center Te s t s b a t t e r y.
For operating instructions, refer to Technical
Service Bulletin and Battery Service Center
User Guide.
—
(J-44373) Model 620
Starting/Charging system tester Tests starting and charging systems.
For operating instructions, refer to Technical
Service Bulletin.
WKIA5280E
SEL403X
Tool name
Description
Power tool Loosening bolts and nuts
PBIC0190E
Revision: March 2010 2008 QX56

DIAGNOSIS AND REPAIR WORKFLOWSTR-5
< BASIC INSPECTION >
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BASIC INSPECTION
DIAGNOSIS AND REPAIR WORKFLOW
Work FlowINFOID:0000000001696223
OVERALL SEQUENCE
DETAILED FLOW
ALBIA0417GB
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2008 QX56

STR-6
< BASIC INSPECTION >
DIAGNOSIS AND REPAIR WORKFLOW
NOTE:
To ensure a complete and thorough diagnosis, the battery, starter motor and alternator test segments must be
done as a set from start to finish.
1.DIAGNOSIS WITH STARTING/CHARGING SYSTEM TESTER
Perform the starting system test with Starting/Charging System Tester (J-44373). For details and operating
instructions, refer to Technical Service Bulletin.
Te s t r e s u l t
CRANKING VOLTAGE NORMAL>>GO TO 2
CRANKING VOLTAGE LOW>>GO TO 5
CHARGE BATTERY>>Perform the slow battery charging procedure. (Initial rate of charge is 10A for 12
hours.) Perform battery test again. Refer to Technical Service Bulletin.
REPLACE BATTERY>>Before replacing battery, clean t he battery cable clamps and battery posts. Perform
battery test again. Refer to Technical Service Bulletin. If second test result is “REPLACE BAT-
TERY”, then do so. Perform battery test again to confirm repair.
2.CRANKING CHECK
Check that the starter motor operates properly.
Does the engine crank normally?
YES >> GO TO 3
NO >> GO TO 4
3.ENGINE START CHECK
Check that the engine starts.
Does the engine start?
YES >> Starter motor is OK. Inspection end.
NO >> Perform further diagnosis of engine mechanical or engine control system. Refer to EM and EC sections. Once resolved, perform battery test again.
4.STARTER MOTOR ACTIVATION
Check that the starter motor operates.
Does the starter motor turn?
YES >> Check ring gear and starter motor drive pinion. Once resolved, perform battery test again.
NO >> GO TO 7
5.COMPARISON BETWEEN ENGINE COOLANT AND CRANKING VOLTAGE
Compare the engine coolant temperature and verify the cranking voltage is within specification.
Minimum Specification of Cranking Voltage Referencing Coolant Temperature
Is the voltage less than the specified value?
YES >> GO TO 7
NO >> GO TO 6
6.STARTER OPERATION
Check the starter operation.
Does the starter motor turn smoothly?
YES >> Starter motor is OK. Inspection end.
NO >> GO TO 7
7.“B” TERMINAL CIRCUIT INSPECTION
Check “B” terminal circuit. Refer to STR-10, "
Diagnosis Procedure".
Is
“B” terminal circuit normal?
Engine coolant temperature [ °C ( °F)] Voltage [V]
− 30 to − 20 (−22 to − 4) 8.6
− 19 to −10 ( −2 to 14) 9.1
− 9 to 0 (16 to 32) 9.5
More than 1 (More than 34) 9.9
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YES >> GO TO 8
NO >> Repair as needed.
8.“S” CONNECTOR CIRCUIT INSPECTION
Check “S” connector circuit. Refer to STR-11, "
Diagnosis Procedure".
Is
“S” connector circuit normal?
YES >> GO TO 9
NO >> Repair as needed.
9.ENGINE ROTATION STATUS
Check that the engine can be rotated by hand.
Does the engine turn freely by hand?
YES >> Replace starter motor.
NO >> Perform further diagnosis of engine mechanical or powertrain mechanism. Refer to EM or TM
sections. Once resolved, perform battery test again. Refer to Technical Service Bulletin.
Revision: March 2010 2008 QX56

STR-8
< FUNCTION DIAGNOSIS >
STARTING SYSTEM
FUNCTION DIAGNOSIS
STARTING SYSTEM
System DiagramINFOID:0000000001696224
System DescriptionINFOID:0000000001696225
The starter motor plunger closes and provides a closed circuit between the battery and the starter motor. The
starter motor is grounded to the cylinder block. With power and ground supplied, the starter motor operates.
Component Parts LocationINFOID:0000000001696226
ALBIA0416GB
1. A/T assembly F9 (with built in TCM
F502) 2. IPDM E/R E119, E120, E122, E124 3. BCM M18 (view with instrument panel
lower LH panel removed)
AWBIA0127ZZ
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STARTING SYSTEMSTR-9
< FUNCTION DIAGNOSIS >
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Component DescriptionINFOID:0000000001696227
Component part
Description
TCM TCM supplies power to the starter relay inside the IPDM E/R
when the selector lever is shifted to the P or N position.
BCM BCM sends a starter request signal to the CPU of the IPDM E/R
over the CAN communication lines.
IPDM E/R CPU inside IPDM E/R operates the starter relay at the request of
the BCM over the CAN communication lines.
Starter motor The starter motor plunger closes and the motor is supplied with
battery power, which in turn cranks the engine, when the “S” ter-
minal is supplied with electric power.
Revision: March 2010
2008 QX56

STR-10
< COMPONENT DIAGNOSIS >
B TERMINAL CIRCUIT
COMPONENT DIAGNOSIS
B TERMINAL CIRCUIT
DescriptionINFOID:0000000001696228
Terminal "2" (B) is constantly supplied with battery power.
Diagnosis ProcedureINFOID:0000000001696229
CAUTION:
Perform diagnosis under the condition that the engine cannot start by the following procedure.
1. Remove fuel pump fuse.
2. Crank or start the engine (where possible) until the fuel pressure is depleted.
1.CHECK TERMINAL 2 POWER SUPPLY VOLTAGE
1. Turn ignition switch OFF.
2. Make sure that starter motor connector F27 terminal 2 connection is clean and tight.
3. Check voltage between starter motor connector F27 terminal 2
and ground.
Is there battery voltage present?
YES >> GO TO 2
NO >> Check harness between battery and starter motor for open circuit.
2.CHECK BATTERY CABLE (VOLTAGE DROP TEST)
1. Shift the transmission into park or neutral.
2. Check voltage between battery positive terminal and starter motor connector F27 terminal 2 while cranking the engine.
Is the voltage drop less than 0.2V?
YES >> GO TO 3
NO >> Check harness between the battery and the starter motor for high resistance.
3.CHECK GROUND CIRCUIT STATUS (VOLTAGE DROP TEST)
Check voltage between starter motor case and battery negative ter-
minal while cranking the engine.
Is the voltage drop less than 0.2V?
YES >> Terminal 2 circuit is OK. Further inspection necessary. Refer to STR-5, "
Work Flow".
NO >> Check the starter motor case to engine mounting for
high resistance.
(+) (-) Voltage
Connector Terminal
F27 2 Ground Battery voltage
AWBIA0122GB
(-) (+) Condition Voltage
Connector Terminal
F27 2 Battery (+)
terminal While cranking the
engine Less than 0.2V
AWBIA0123GB
(+)
(-)Condition Voltage
Starter motor case Battery (-) terminal While cranking the
engine Less than 0.2V
AWBIA0124GB
Revision: March 2010
2008 QX56

S CONNECTOR CIRCUITSTR-11
< COMPONENT DIAGNOSIS >
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S CONNECTOR CIRCUIT
DescriptionINFOID:0000000001696230
Terminal "1" (S) is the power supply for the starter mo
tor magnetic switch. Terminal 1 is supplied with power
when the ignition switch is turned to the START position while the selector lever is in the P or N position.
Diagnosis ProcedureINFOID:0000000001696231
CAUTION:
Perform diagnosis under the cond ition that engine cannot start by the following procedure.
1. Remove fuel pump fuse.
2. Crank or start the engine (where possi ble) until the fuel pressure is released.
1.CHECK STARTER MOTOR MAGNETIC SWITCH CIRCUIT
1. Turn ignition switch OFF.
2. Disconnect starter motor connector F28.
3. Shift transmission into park or neutral.
4. Check voltage between starter motor harness connector F28 terminal 1 and ground with the ignition in START.
Is battery voltage present?
YES >> Magnetic switch circuit is OK. Further inspection necessary. Refer to STR-5, "Work Flow".
NO >> GO TO 2
2.CHECK CONNECTOR
1. Turn ignition switch OFF.
2. Check the IPDM E/R harness connector E120 and starter motor harness connector F28 for damage, bent pins and loose connections.
Is the inspection result normal?
YES >> GO TO 3
NO >> Repair the terminal and connector.
3.CHECK HARNESS CONTI NUITY (OPEN CIRCUIT)
1. Disconnect IPDM E/R connector E120 and starter motor con- nector F28.
2. Check continuity between starter motor harness connector F28 (A) terminal 1 and IPDM E/R harness connector E120 (B) termi-
nal 19.
3. Check continuity between starter motor harness connector F28 (A) terminal 1 and ground.
Are the continuity test results as specified?
YES >> Further inspection necessary. Refer to STR-5, "Work Flow".
NO >> Repair the harness.
(+) (-)Condition Voltage
Connector Terminal
F28 1 Ground While cranking the
engine Battery voltage
AWBIA0125GB
AB
Continiuty
Connector Terminal Connector Terminal
F28 1E120 19 Yes
A —Continiuty
Connector Terminal
F28 1Ground No
AWBIA0126GB
Revision: March 2010 2008 QX56