2008 INFINITI QX56 engine

CHG-6
< BASIC INSPECTION >
DIAGNOSIS AND REPAIR WORKFLOW
NOTE:
To ensure a complete and thorough diagnosis, the battery, starter and generator test segments must be done
as a set from start to finish.
1.PRELIMINARY INSPECTION
Perform the preliminary inspection. Refer to CHG-10, "
Inspection Procedure".
>> GO TO 2.
2.DISABLE THE POWER GENERATION VO LTAGE VARIABLE CONTROL SYSTEM
Disable the power generation voltage variable control with either of the following procedures.
• After selecting “ENGINE” on the “SELECT SYSTEM” screen of CONSULT-III, set the “ALTERNATOR DUTY” value to 0 % by selecting “ALTERNATOR DUTY” with “Active Test”. Continue “Active Test” until the end of
inspection. (When the DUTY value is 0 or 100 %, the normal power generation is performed according to the
characteristic of the IC regulator of the generator.)
• Turn the ignition switch OFF, disconnect the battery current sensor connector and leave it disconnected dur-
ing the course of the test.
NOTE:
Running the engine with the battery current sensor disconnected will cause DTC's (P1550-P1554) to set.
After finishing the inspection, connect the battery current sensor connector and erase the self-diagnostic
results history of the engine using CONSULT-III.
>> GO TO 3.
3.DIAGNOSIS WITH STARTING /CHARGING SYSTEM TESTER
Perform the charging system test using Starting/Charging System Test er (J-44373). For details and operating
instructions, refer to Technical Service Bulletin.
Te s t r e s u l t
CHARGING SYSTEM NOMAL>>Charging system is normal and will also show “DIODE RIPPLE” test result.
NO CHARGING VOLTAGE>>GO TO 4.
LOW CHARGING VOLTAGE>>GO TO 12.
HIGH CHARGING VOLTAGE>>GO TO 14.
DIODE RIPPLE NORMAL>>Diode ripple is OK and will also show “CHARGING VOLTAGE” test result.
EXCESS RIPPLE DETECTED>>Replace the generator. Perf orm “DIODE RIPPLE” test again using Starting/
Charging System Tester (J -44373) to confirm repair.
DIODE RIPPLE NOT DETECTED>>GO TO 4.
4.INSPECTION WITH CHARGE WARNING LAMP (IGNITION SWITCH IS ON)
Turn the ignition switch ON.
Does the charge warning lamp illuminate?
YES >> GO TO 6.
NO >> GO TO 5.
5.TERMINAL“2” (OPEN) CIRCUIT INSPECTION
Check terminal “2” circuit for open circuits. Refer to CHG-14, "
Diagnosis Procedure".
Is the terminal
“2” circuit normal?
YES >> Replace generator.
NO >> Repair as needed.
6.INSPECTION WITH CHARGE WARNING LAMP (IDLING)
Start the engine and run it at idle.
Does the charge warning lamp turn OFF?
YES >> GO TO 9.
NO >> GO TO 7.
7.TERMINAL “2”(SHORT) CIRCUIT INSPECTION
Check terminal “2” circuit for short to ground. Refer to CHG-14, "
Diagnosis Procedure".
Is the terminal
“2” circuit normal?
Revision: March 2010 2008 QX56

CHG
DIAGNOSIS AND REPAIR WORKFLOWCHG-7
< BASIC INSPECTION >
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YES >> GO TO 8.
NO >> Repair as needed.
8.TERMINAL“3” CIRCUIT INSPECTION
Check terminal “3” circuit. Refer to CHG-15, "
Diagnosis Procedure".
Is the terminal
“3” circuit normal?
YES >> GO TO 10.
NO >> Repair as needed.
9.INSPECTION WITH CHARGE WARNING LAMP (ENGINE AT 3,000 RPM)
Increase and maintain the engine speed at 3,000 rpm.
Does the charge warning lamp remain off?
YES >> GO TO 11.
NO >> GO TO 10.
10.INSPECTION OF GENERATOR PULLEY
Check generator pulley.
Is generator pulley normal?
YES >> Replace generator. Refer to CHG-22, "Removal and Installation".
NO >> Repair as needed.
11 .TERMINAL “1” CIRCUIT INSPECTION
Check terminal “1””circuit. Refer to CHG-13, "
Diagnosis Procedure".
Is terminal
“1” circuit normal?
YES >> Replace generator. Refer to CHG-22, "Removal and Installation".
NO >> Repair as needed.
12.TERMINAL “1” CIRCUIT INSPECTION
Check terminal “1” circuit. Refer to CHG-13, "
Diagnosis Procedure".
Is terminal
“1” circuit normal?
YES >> GO TO 13.
NO >> Repair as needed.
13.INSPECTION OF GENERATOR PULLEY
Check generator pulley.
Is generator pulley normal?
YES >> Replace generator. Refer to CHG-22, "Removal and Installation".
NO >> Repair as needed.
14.TERMINAL “3” CIRCUIT INSPECTION
Check terminal“3” circuit. Refer to CHG-15, "
Diagnosis Procedure".
Is the terminal
“3” circuit normal?
YES >> Replace generator. Refer to CHG-22, "Removal and Installation".
NO >> Repair as needed.
Revision: March 2010 2008 QX56

CHG
POWER GENERATION VOLTAGE VARIABLE CONTROL SYSTEM
CHG-9
< FUNCTION DIAGNOSIS >
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POWER GENERATION VOLTAG
E VARIABLE CONTROL SYSTEM
System DiagramINFOID:0000000001696181
System DescriptionINFOID:0000000001696182
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:0000000001696183
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.
Revision: March 2010
2008 QX56

CHG
POWER GENERATION VOLTAGE VARIABLE CONTROL SYSTEM OPERATION
INSPECTION
CHG-11
< COMPONENT DIAGNOSIS >
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POWER GENERATION VOLTAGE VARI
ABLE CONTROL SYSTEM OPER-
ATION INSPECTION
Inspection ProcedureINFOID:0000000001696185
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
1. Turn ignition switch OFF.
2. Disconnect generator connector E205 and IPDM E/R connector E122.
3. Check continuity between generator harness connector E205 (A) terminal 4 and IPDM E/R harness connector E122 (B) termi-
nal 37. “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 %
AB
Continuity
Connector Terminal Connector Terminal
E205 4E122 37Yes
ALMIA0196ZZ
Revision: March 2010 2008 QX56

CHG
B TERMINAL CIRCUITCHG-13
< COMPONENT DIAGNOSIS >
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B TERMINAL CIRCUIT
DescriptionINFOID:0000000001696186
The terminal “1” circuit supplies power to charge the battery and operate the vehicles electrical system.
Diagnosis ProcedureINFOID:0000000001696187
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 Technical Service Bulletin.
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: March 2010 2008 QX56

CHG-14
< COMPONENT DIAGNOSIS >
L TERMINAL CIRCUIT
L TERMINAL CIRCUIT
DescriptionINFOID:0000000001696188
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:0000000001696189
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 Technical Service Bulletin.
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-76, "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
AWMIA0596ZZ
Revision: March 2010 2008 QX56

CHG
CHARGING SYSTEMCHG-21
< SYMPTOM DIAGNOSIS >
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SYMPTOM DIAGNOSIS
CHARGING SYSTEM
Symptom TableINFOID:0000000001696193
Symptom
Reference
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: March 2010
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CO-1
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 ..........................................5
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
Removal and Installation ..................................... ....15
ENGINE COOLING FAN ...................................18
Removal and Installation (Crankshaft Driven
Type) .......................................................................
18
Removal and Installation (Motor Driven Type) ........19
WATER PUMP ..................................................20
Removal and Installation .........................................20
THERMOSTAT AND WATER PIPING ..............22
Removal and Installation .........................................22
SERVICE DATA AND SPECIFICATIONS
(SDS) ............... .......................................... ...
24
SERVICE DATA AND SPECIFICATIONS
(SDS) .................................................................
24
Standard and Limit .............................................. ....24
Revision: March 2010 2008 QX56