2011 INFINITI QX56 engine

CHG-14
< BASIC INSPECTION >
DIAGNOSIS AND REPAIR WORKFLOW
NOTE:
To ensure a complete and thorough diagnosis, the battery, starter and alternator test segments must be done
as a set from start to finish.
1.PRELIMINARY INSPECTION
Perform the preliminary inspection. Refer to CHG-16, "
Inspection Procedure".
>> GO TO 2.
2.STOP POWER GENERATION VOLT AGE VARIABLE CONTROL SYSTEM
Stop the operation of the power generation voltage variabl e control in either of the following procedures.
 After selecting “ENGINE” of “SELECT SYSTEM” usi ng CONSULT-III, set the DUTY value of “ALTERNATOR
DUTY” to 0 % by selecting “ALTERNATOR DUTY” of “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 voltage regulator of the alternator.)
 Turn the ignition switch OFF, and disconnect the batte ry current sensor connector. [However, DTC (P1550 -
P1554) of the engine might remain. After finishing the inspection, connect the battery current sensor connec-
tor and erase the self-diagnosis results history of the engine using CONSULT-III.]
>> GO TO 3.
3.DIAGNOSIS WITH STARTING /CHARGING SYSTEM TESTER
Perform the charging system test us ing Starting/Charging System Tester (SST: J-44373). For details and oper-
ating instructions, refer to Technical Service Bulletin.
Te s t r e s u l t
CHARGING SYSTEM NORMAL>>Char ging 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 alternator. Perform “DIODE RIPPLE” test again using Starting/
Charging System Tester (SST : 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.“L” TERMINAL CIRCUIT (OPEN) INSPECTION
Check “L” terminal circuit (open). Refer to CHG-20, "
Diagnosis Procedure".
Is the
“L” terminal circuit normal?
YES >> Replace alternator.
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.“L” TERMINAL CIRCUIT (SHORT) INSPECTION
Check “L” terminal circuit (short). Refer to CHG-22, "
Diagnosis Procedure".
Is the
“L” terminal circuit normal?
YES >> GO TO 8.
NO >> Repair as needed.
Revision: 2010 May2011 QX56

CHG
DIAGNOSIS AND REPAIR WORKFLOWCHG-15
< BASIC INSPECTION >
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B A
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8.“S” TERMINAL CIRCUIT INSPECTION
Check “S” terminal circuit. Refer to CHG-23, "
Diagnosis Procedure".
Is the
“S” terminal 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 ALTERNATOR PULLEY
Check alternator pulley. Refer to CHG-28, "
Inspection".
Is alternator pulley normal?
YES >> Replace alternator.
NO >> Repair as needed.
11 .“B” TERMINAL CIRCUIT INSPECTION
Check “B” terminal circuit. Refer to CHG-19, "
Diagnosis Procedure".
Is
“B” terminal circuit normal?
YES >> Replace alternator.
NO >> Repair as needed.
12.“B” TERMINAL CIRCUIT INSPECTION
Check “B” terminal circuit. Refer to CHG-19, "
Diagnosis Procedure".
Is
“B” terminal circuit normal?
YES >> GO TO 13.
NO >> Repair as needed.
13.INSPECTION OF ALTERNATOR PULLEY
Check alternator pulley. Refer to CHG-28, "
Inspection".
Is alternator pulley normal?
YES >> Replace alternator.
NO >> Repair as needed.
14.“S” TERMINAL CIRCUIT INSPECTION
Check “S” terminal circuit. Refer to CHG-23, "
Diagnosis Procedure".
Is the
“S” terminal circuit normal?
YES >> Replace alternator.
NO >> Repair as needed.
Revision: 2010 May2011 QX56

CHG
POWER GENERATION VOLTAGE VARIABLE CONTROL SYSTEM OPERATION
INSPECTION
CHG-17
< BASIC INSPECTION >
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POWER GENERATION VOLTAGE VA
RIABLE CONTROL SYSTEM OPER-
ATION INSPECTION
Inspection ProcedureINFOID:0000000006274867
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".
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. shift the selector lever to “P” or “N” position and turn off all of the electric loads and A/C, etc.
3. Select “ALTERNATOR DUTY” at “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 value within the 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-12, "
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 ALTE RNATOR AND IPDM E/R
1. Turn ignition switch OFF.
2. Disconnect alternator harness connec tor and IPDM E/R harness connector.
3. Check continuity between alternator har ness connector and IPDM E/R harness connector.
4. Check continuity between alte rnator harness connector and ground.
“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 %
Alternator IPDM E/R
Continuity
Connector Terminal Connector Terminal
E205 5 E13 33 Existed
Revision: 2010 May2011 QX56

CHG
B TERMINAL CIRCUITCHG-19
< DTC/CIRCUIT DIAGNOSIS >
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DTC/CIRCUIT DIAGNOSIS
B TERMINAL CIRCUIT
DescriptionINFOID:0000000006274868
“B” terminal circuit supplies power to charge the bat
tery and to operate the vehicle’s electrical system.
Diagnosis ProcedureINFOID:0000000006274869
1.CHECK “B” TERMINAL CONNECTION
1. Turn ignition switch OFF.
2. Check that “B” terminal is clean and tight.
Is the inspection result normal?
YES >> GO TO 2.
NO >> Repair “B” terminal connection. Confirm repair by performing complete Starting/Charging system test. Refer to Technical Service Bulletin.
2.CHECK “B” TERMINAL CIRCUIT
Check voltage between alternator “B” terminal and ground.
Is the inspection result normal?
YES >> GO TO 3.
NO >> Check harness for open between alternator and fusible link.
3.CHECK “B” TERMINAL CONNECT ION (VOLTAGE DROP TEST)
1. Start engine, then engine running at idle and warm.
2. Check voltage between battery positive terminal and alternator “B” terminal.
Is the inspection result normal?
YES >> “B” terminal circuit is normal. Refer to CHG-13, "Work Flow".
NO >> Check harness between battery and alternator for poor continuity.
(+)
(–) Voltage
Alternator “B” terminal
E203 1 Ground Battery voltage
(+) (–)
Voltage (V)
(Approx.)
Alternator “B” terminal Terminal
Battery positive terminal E203 1 Less than 0.2
Revision: 2010 May2011 QX56

CHG-20
< DTC/CIRCUIT DIAGNOSIS >
L TERMINAL CIRCUIT (OPEN)
L TERMINAL CIRCUIT (OPEN)
DescriptionINFOID:0000000006274870
The “L” terminal circuit controls the charge warning lamp. The charge warning lamp illuminates when the igni-
tion switch is set to ON or START. When the alternat or is providing sufficient voltage with the engine running,
the charge warning lamp will go off. If the charge warn ing lamp illuminates with the engine running, a malfunc-
tion is indicated.
Diagnosis ProcedureINFOID:0000000006274871
1.CHECK “L” TERMINAL CONNECTION
1. Turn ignition switch OFF.
2. Check that “L” terminal is clean and tight.
Is the inspection result normal?
YES >> GO TO 2.
NO >> Repair “L” terminal connection. Confirm repair by performing complete Starting/Charging system test. Refer to Technical Service Bulletin.
2.CHECK “L” TERMIN AL CIRCUIT (OPEN)
1. Disconnect alternator connector.
2. Apply ground to alternator harness connector terminal.
3. Check condition of the charge warning lamp with the ignition switch in the ON position.
Does it illuminate?
YES >> “L” terminal circuit is normal. Refer to CHG-13, "Work Flow".
NO >> GO TO 3.
3.CHECK HARNESS CONTI NUITY (OPEN CIRCUIT)
1. Disconnect the battery cable from the negative terminal.
2. Disconnect the combination meter connector.
3. Check continuity between alternator harness connector and combination meter harness connector.
Is the inspection result normal?
YES >> GO TO 4.
NO >> Repair the harness or connector.
4.CHECK HARNESS CONTI NUITY (OPEN CIRCUIT)
Check continuity between combination me ter harness connector and fuse block (J/B).
Is the inspection result normal?
YES >> GO TO 5.
NO >> Repair the harness or connector.
5.CHECK POWER SUPPLY CIRCUIT
(+) (–) Condition Charge warning lamp
Alternator
Connector Terminal E205 3 Ground Ignition switch ON ON
Alternator Combination meter Continuity
Connector Terminal Connector Terminal
E205 3 M34 25 Existed
Combination meter Fuse block (J/B) Continuity
Connector Terminal Connector Terminal
M34 2 M1 2A Existed
Revision: 2010 May2011 QX56

CHG-22
< DTC/CIRCUIT DIAGNOSIS >
L TERMINAL CIRCUIT (SHORT)
L TERMINAL CIRCUIT (SHORT)
DescriptionINFOID:0000000006274872
The “L” terminal circuit controls the charge warning lamp. The charge warning lamp illuminates when the igni-
tion switch is set to ON or START. When the alternat or is providing sufficient voltage with the engine running,
the charge warning lamp will go off. If the charge warn ing lamp illuminates with the engine running, a malfunc-
tion is indicated.
Diagnosis ProcedureINFOID:0000000006274873
1.CHECK “L” TERMINAL CIRCUIT (SHORT)
1. Turn ignition switch OFF.
2. Disconnect alternator connector.
3. Turn ignition switch ON.
Does charge warning lamp illuminate?
YES >> GO TO 2.
NO >> Refer to CHG-13, "
Work Flow".
2.CHECK HARNESS CONTI NUITY (SHORT CIRCUIT)
1. Turn the ignition switch OFF.
2. Disconnect the battery cable from the negative terminal.
3. Disconnect combination meter connector.
4. Check continuity between combination meter harness connector and ground.
Is the inspection result normal?
YES >> Replace combination meter.
NO >> Repair the harness or connector.
Combination meter
GroundContinuity
Connector Terminal
M34 25 Not existed
Revision: 2010 May2011 QX56

CHG-24
< SYMPTOM DIAGNOSIS >
CHARGING SYSTEM
SYMPTOM DIAGNOSIS
CHARGING SYSTEM
Symptom TableINFOID:0000000006274876
Symptom Reference
Discharged battery
Refer to CHG-13, "
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: 2010 May2011 QX56

CHG-26
< REMOVAL AND INSTALLATION >
ALTERNATOR
Type: A002TX1491
Removal and InstallationINFOID:0000000006274878
REMOVAL
1. Disconnect the battery cable from the negative terminal. Refer to PG-164, "Removal and Installation".
2. Remove front under cover. Refer to EXT-25, "
Removal and Installation".
3. Remove drive belt. Refer to EM-20, "
Removal and Installation".
4. Disconnect engine oil pressure switch connector (A) and alter- nator connector (B).
5. Remove harness bracket bolt (C).
6. Remove “B” terminal nut (D) and disconnect “B” terminal har- ness.
JMMIA0363GB
1. Rear bearing 2. Rotor assembly 3. Retainer
4. Front bearing 5. Front bracket assembly 6. Pulley
7. Pulley nut 8. Stator assembly 9. IC voltage regulator assembly
10. Diode assembly 11. Rear bracket assembly 12. Terminal set
Refer to GI-4, "
Components" for symbols in the figure.
JMMIA0364ZZ
Revision: 2010 May2011 QX56