2010 INFINITI QX56 engine

CHG-2
< PRECAUTION >
PRECAUTIONS
PRECAUTION
PRECAUTIONS
Precaution for Supplemental Restraint System (SRS) "AIR BAG" and "SEAT BELT
PRE-TENSIONER"
INFOID:0000000005260140
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:0000000005260141
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.
Revision: April 20092010 QX56

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PRECAUTIONSCHG-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:0000000005146547
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: April 20092010 QX56

CHG
POWER GENERATION VOLTAGE VARIABLE CONTROL SYSTEM
CHG-7
< FUNCTION DIAGNOSIS >
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POWER GENERATION VOLTAG
E VARIABLE CONTROL SYSTEM
System DiagramINFOID:0000000005146554
System DescriptionINFOID:0000000005146555
Power generation variable voltage control system has been adopted. By varying the voltage to the generator,
engine load due to power generation of the generator is reduced and fuel consumption is decreased.
NOTE:
When any malfunction is detected in the power generat ion variable voltage control system, power generation
is performed according to the characterist ic of the IC regulator in the generator.
Component DescriptionINFOID:0000000005146556
ALMIA0057GB
Component part Description
Battery current sensor The battery current sensor is installed on the battery cable at the
negative terminal. The battery current sensor detects the charg-
ing/discharging current of the battery and sends a voltage signal
to the ECM according to the current value detected.
ECM The battery current sensor detects the charging/discharging cur-
rent of the battery. The ECM judges the battery condition based on
this signal.
The ECM judges whether to request more output via the power
generation voltage variable control according to the battery condi-
tion.
When performing the power generation voltage variable control,
the ECM calculates the target power generation voltage according
to the battery condition and sends the calculated value as the pow-
er generation command value to the IPDM E/R.
IPDM E/R The IPDM E/R converts the received power generation command
value into a pulse width modulated (PWM) command signal and
sends it to the IC regulator.
Generator (IC regulator) The IC regulator controls the power generation voltage by the tar-
get power generation voltage based on the received PWM com-
mand signal.
When there is no PWM command signal, the generator performs
the normal power generation according to the characteristic of the
IC regulator.
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POWER GENERATION VOLTAGE VARIABLE CONTROL SYSTEM OPERATION
INSPECTION
CHG-9
< COMPONENT DIAGNOSIS >
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POWER GENERATION VOLTAGE VARI
ABLE CONTROL SYSTEM OPER-
ATION INSPECTION
Diagnosis ProcedureINFOID:0000000005146558
Regarding Wiring Diagram information, refer to CHG-14, "Wiring Diagram".
CAUTION:
When performing this inspection, always use a charged battery that has completed the battery inspec-
tion. (When the charging rate of the battery is low, the response speed of the voltage change will
become slow. This can cause an incorrect inspection.)
1.CHECK ECM (CONSULT-III)
Perform ECM self-diagnosis with CONSULT-III. Refer to EC-63, "
CONSULT-III Function (ENGINE)".
Self
-diagnostic results content
No malfunction detected>> GO TO 2.
Malfunction detected>> Check applicable parts, and repair or replace corresponding parts.
2.CHECK OPERATION OF POWER GENERATION VOLTAGE VARIABLE CONTROL SYSTEM
1. Connect CONSULT-III and start the engine.
2. The selector lever is in “P” or “N” position and a ll of the electric loads and A/C, etc. are turned OFF.
3. Select “ALTERNATOR DUTY” in “Active Test” of “ENGINE”, and then check the value of “BATTERY
VOLT” monitor when DUTY value of “ALTERNATOR DUTY” is set to 40.0 %.
4. Check the value of “BATTERY VOLT” monitor when DUTY value of “ALTERNATOR DUTY” is set to 80.0%.
Is the measurement val ue within specification?
YES >> Inspection End.
NO >> GO TO 3.
3.CHECK IPDM E/R (CONSULT-III)
Perform IPDM E/R self-diagnosis with CONSULT-III. Refer to PCS-14, "
CONSULT - III Function (IPDM E/R)".
Self
-diagnostic results content
No malfunction detected>> GO TO 4.
Malfunction detected>> Check applicable parts, and repair or replace corresponding parts.
4.CHECK HARNESS BETWEEN GE NERATOR AND IPDM E/R
“BATTERY VOLT”
2 seconds after setting the
DUTY value of “ALTERNA-
TOR DUTY” to 40.0 %
: 12 - 13.6 V
“BATTERY VOLT”
20 seconds after setting
the DUTY value of “ALTER-
NATOR DUTY” to 80.0 % : +0.5 V or more against
the value of “BATTERY
VOLT” monitor when
DUTY value is 40.0 %
Revision: April 20092010 QX56

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B TERMINAL CIRCUITCHG-11
< COMPONENT DIAGNOSIS >
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B TERMINAL CIRCUIT
DescriptionINFOID:0000000005146559
The terminal “1” circuit supplies power to charge the battery and operate the vehicles electrical system.
Diagnosis ProcedureINFOID:0000000005146560
Regarding Wiring Diagram information, refer to
CHG-14, "Wiring Diagram".
1.CHECK TERMINAL “1” CONNECTION
1. Turn ignition switch OFF.
2. Verify terminal “1” is clean and tight.
Is the inspection result normal?
YES >> GO TO 2.
NO >> Repair terminal “1” connection. Confirm repa ir by performing complete Starting/Charging system
test. Refer to diagnostic station instruction manual.
2.CHECK TERMINAL “1” CIRCUIT
Check voltage between generator connector E204 terminal 1 and
ground.
Is voltage reading as specified?
YES >> GO TO 3.
NO >> Check harness for open between generator and fusible link.
3.CHECK TERMINAL “1” CONNECTION (VOLTAGE DROP TEST)
1. Start engine, then engine running at idle and warm.
2. Check voltage between battery positive terminal and generator connector E204 terminal 1.
Is the voltage reading as specified?
YES >> Terminal “1” circuit is normal. Refer to CHG-5, "Work
Flow".
NO >> Check harness between battery and generator for high resistance.
(+) (-) Voltage
Connector Terminal
E204 1Ground Battery voltage
ALMIA0197ZZ
(+)
(-)Voltage
Connector Terminal
E204 1 Battery positive terminal Less than 0.2V
ALMIA0198ZZ
Revision: April 20092010 QX56

CHG-12
< COMPONENT DIAGNOSIS >
L TERMINAL CIRCUIT
L TERMINAL CIRCUIT
DescriptionINFOID:0000000005146561
The terminal “2” (L) circuit controls the charge warning lamp. The charge warning lamp illuminates when the
ignition switch is set to ON or START. When the generator is providing sufficient voltage with the engine run-
ning, the charge warning lamp will go off. If the c harge warning lamp illuminates with the engine running, a
malfunction is indicated.
Diagnosis ProcedureINFOID:0000000005146562
Regarding Wiring Diagram information, refer to CHG-14, "Wiring Diagram".
1.CHECK CHARGE WARNING LAMP CIRCUIT CONNECTION
Verify generator connector E205 terminal 2 is clean and tight.
Is the connection secure?
YES >> GO TO 2.
NO >> Repair the connection. Confirm repair by per forming complete Starting/Charging system test.
Refer to diagnostic station instruction manual.
2.CHECK CHARGE WARNING LAMP CIRCUIT
1. Disconnect generator connector E205.
2. Apply ground to generator harness connector E205 terminal 2 with the ignition switch in the ON position.
Does the charge lamp illuminate?
YES >> Check generator function. Refer to CHG-5, "Work Flow".
NO >> GO TO 3.
3.CHECK HARNESS CONTINUITY
1. Turn ignition switch OFF.
2. Disconnect the generator connector E205 and combination meter connector M24.
3. Check continuity between generator harness connector E205 (A) terminal 2 and combination meter harness connector M24
(B) terminal 6.
4. Check continuity between generator harness connector E205 (A) terminal 2 and ground.
Are the continuity results as specified?
YES >> Replace the combination meter. Refer to MWI-100, "Removal and Installation".
NO >> Repair the harness or connector. Charge lamp should illuminate
ALMIA0200ZZ
AB
Continuity
Connector Terminal Connector Terminal
E205 2M24 6Yes
A —
Continuity
Connector Terminal
E205 2Ground No
AWMIA1099ZZ
Revision: April 20092010 QX56

CHG-20
< SYMPTOM DIAGNOSIS >
CHARGING SYSTEM
SYMPTOM DIAGNOSIS
CHARGING SYSTEM
Symptom TableINFOID:0000000005146566
SymptomReference
Battery discharged
Refer to CHG-5, "
Work Flow".
The charge warning lamp does not illuminate when the ignition
switch is set to ON.
The charge warning lamp does not turn OFF after the engine
starts.
The charging warning lamp turns ON when increasing the engine
speed.
Revision: April 20092010 QX56

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ENGINE
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SECTION CO
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CONTENTS
ENGINE COOLING SYSTEM
PRECAUTION ....... ........................................2
PRECAUTIONS .............................................. .....2
Precaution for Supplemental Restraint System
(SRS) "AIR BAG" and "SEAT BELT PRE-TEN-
SIONER" ............................................................. ......
2
Precaution Necessary for Steering Wheel Rota-
tion After Battery Disconnect ............................... ......
2
Precaution for Liquid Gasket .....................................3
PREPARATION ............................................4
PREPARATION .............................................. .....4
Special Service Tool ........................................... ......4
Commercial Service Tool ..........................................4
FUNCTION DIAGNOSIS ...............................6
COOLING SYSTEM ....................................... .....6
Cooling Circuit ..................................................... ......6
Schematic .................................................................7
OVERHEATING CAUSE ANALYSIS ..................8
Troubleshooting Chart ...............................................8
ON-VEHICLE MAINTENA NCE ....................10
ENGINE COOLANT ....................................... ....10
Inspection ............................................................ ....10
Changing Engine Coolant .......................................11
RADIATOR ........................................................14
Checking Radiator ............................................... ....14
ON-VEHICLE REPAIR .................................15
RADIATOR ....... .................................................15
Exploded View ..................................................... ....15
Removal and Installation .........................................15
ENGINE COOLING FAN ...................................18
Exploded View .........................................................18
Removal and Installation (Crankshaft Driven
Type) .......................................................................
18
Removal and Installation (Motor Driven Type) ........19
WATER PUMP ..................................................20
Exploded View .........................................................20
Removal and Installation .........................................20
THERMOSTAT AND WATER PIPING ..............22
Exploded View .........................................................22
Removal and Installation .........................................22
SERVICE DATA AND SPECIFICATIONS
(SDS) ............... .......................................... ...
24
SERVICE DATA AND SPECIFICATIONS
(SDS) .................................................................
24
Standard and Limit .............................................. ....24
Revision: April 20092010 QX56