2011 INFINITI QX56 alternator

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ELECTRICAL & POWER CONTROL
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SECTION CHG
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CONTENTS
CHARGING SYSTEM
PRECAUTION ................
...............................3
PRECAUTIONS .............................................. .....3
Precaution for Supplemental Restraint System
(SRS) "AIR BAG" and "SEAT BELT PRE-TEN-
SIONER" ............................................................. ......
3
Precaution Necessary for Steering Wheel Rota-
tion after Battery Disconnect .....................................
3
Precaution for Power Generation Voltage Variable
Control System ..........................................................
4
PREPARATION ............................................5
PREPARATION .............................................. .....5
Special Service Tools .......................................... ......5
Commercial Service Tools ........................................5
SYSTEM DESCRIPTION ..............................6
COMPONENT PARTS ................................... .....6
Component Parts Location .................................. ......6
Component Description ............................................6
SYSTEM ..............................................................7
CHARGING SYSTEM ..................................................7
CHARGING SYSTEM : System Diagram ........... ......7
CHARGING SYSTEM : System Description .............7
POWER GENERATION VOLTAGE VARIABLE
CONTROL SYSTEM .............................................. ......
7
POWER GENERATION VOLTAGE VARIABLE
CONTROL SYSTEM : System Diagram ...................
7
POWER GENERATION VOLTAGE VARIABLE
CONTROL SYSTEM : System Description ...............
7
WIRING DIAGRAM ........ ...............................9
CHARGING SYSTEM ..................................... .....9
Wiring Diagram ................................................... ......9
BASIC INSPECTION ...................................13
DIAGNOSIS AND REPAIR WORKFLOW ........13
Work Flow ............................................................ ....13
CHARGING SYSTEM PRELIMINARY IN-
SPECTION ....................................... .................
16
Inspection Procedure ........................................... ....16
POWER GENERATION VOLTAGE VARI-
ABLE CONTROL SYSTEM OPERATION IN-
SPECTION ....................................... .................
17
Inspection Procedure ........................................... ....17
DTC/CIRCUIT DIAGNOSIS .........................19
B TERMINAL CIRCUIT .....................................19
Description ........................................................... ....19
Diagnosis Procedure ...............................................19
L TERMINAL CIRCUIT (OPEN) ........................20
Description ...............................................................20
Diagnosis Procedure ...............................................20
L TERMINAL CIRCUIT (SHORT) .....................22
Description ...............................................................22
Diagnosis Procedure ...............................................22
S TERMINAL CIRCUIT .....................................23
Description ...............................................................23
Diagnosis Procedure ...............................................23
SYMPTOM DIAGNOSIS ..............................24
CHARGING SYSTEM .......................................24
Symptom Table ................................................... ....24
REMOVAL AND INSTALLATION ...............25
ALTERNATOR ................................. .................25
Exploded View ..................................................... ....25
Removal and Installation .........................................26
Inspection ................................................................28
Revision: 2010 May2011 QX56

CHG-2
SERVICE DATA AND SPECIFICATIONS
(SDS) .............. .............................................
29
SERVICE DATA AND SPECIFICATIONS
(SDS) .............................................................. ...
29
Alternator ............................................................. ...29
Revision: 2010 May2011 QX56

CHG-6
< SYSTEM DESCRIPTION >
COMPONENT PARTS
SYSTEM DESCRIPTION
COMPONENT PARTS
Component Parts LocationINFOID:0000000006274858
Component DescriptionINFOID:0000000006274859
1. IPDM E/RRefer to PCS-4, "
Component Parts
Location". 2. ECM
Refer to EC-16, "
Component Parts
Location". 3. Battery current sensor
Refer to EC-16, "
Component Parts
Location".
4. Alternator 5. Combination meter (charge warning lamp)
Refer to MWI-6, "
METER SYSTEM :
Component Parts Location".
A. Engine room (RH)
JMMIA0411ZZ
Component part Description
Alternator (IC voltage regulator) IC voltage regulator controls the power generation voltage by the target power genera-
tion voltage based on the received power generation command signal.
When there is no power generation command signal, the alternator performs the normal
power generation according to the characteristic of the IC voltage regulator.
Battery current sensor Battery current sensor is installed to the battery cable at the negative terminal, and it de-
tects the charging/discharging current of the battery and sends the voltage signal to ECM
according to the current value.
Combination meter (C harge warning lamp) The IC voltage regulator warning function activates to illuminate the charge warning
lamp, if any of the following symptoms occur while alternator is operating:
 Excessive voltage is produced.
 No voltage is produced.
ECM Battery current sensor detects the charging/discharging current of the battery. ECM judg-
es the battery condition based on this signal.
ECM judges whether to perform the power generation voltage variable control according
to the battery condition.
When performing the power generation voltage variable control, ECM calculates the tar-
get power generation voltage according to the battery condition and sends the calculated
value as the power generation command value to IPDM E/R.
IPDM E/R IPDM E/R converts the received power generation command value into the power gen-
eration command signal (PWM signal) and sends it to the IC voltage regulator.
Revision: 2010 May2011 QX56

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< SYSTEM DESCRIPTION >
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SYSTEM
CHARGING SYSTEM
CHARGING SYSTEM : System DiagramINFOID:0000000006274860
CHARGING SYSTEM : System DescriptionINFOID:0000000006274861
The alternator provides DC voltage to operate the vehi
cle's electrical system and to keep the battery charged.
The voltage output is controlled by the IC voltage regulator.
POWER GENERATION VOLTAGE VARIABLE CONTROL SYSTEM
POWER GENERATION VOLTAGE VARIABL E CONTROL SYSTEM : System Dia-
gram
INFOID:0000000006274862
POWER GENERATION VOLTAGE VARIABL E CONTROL SYSTEM : System De-
JPMIA0633GB
JPMIA0632GB
Revision: 2010 May2011 QX56

CHG-8
< SYSTEM DESCRIPTION >
SYSTEM
scription
INFOID:0000000006274863
By performing the power generation voltage variable c ontrol, the engine load due to the power generation of
the alternator is reduced and fuel consumption is decreased.
NOTE:
When any malfunction is detected in the power generat ion voltage variable control system, the power genera-
tion is performed according to the characteristic of the IC voltage regulator of the alternator.
Revision: 2010 May2011 QX56

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

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DIAGNOSIS AND REPAIR WORKFLOWCHG-15
< BASIC INSPECTION >
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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-16
< BASIC INSPECTION >
CHARGING SYSTEM PRELIMINARY INSPECTION
CHARGING SYSTEM PRELIMINARY INSPECTION
Inspection ProcedureINFOID:0000000006274866
1.CHECK BATTERY TERMINALS CONNECTION
Check if battery terminals are clean and tight.
Is the inspection result normal?
YES >> GO TO 2.
NO >> Repair battery terminals connection.
2.CHECK FUSE
Check for blown fuse and fusible link.
Is the inspection result normal?
YES >> GO TO 3.
NO >> Replace the blown fuse after repairing the applicable circuit.
3.CHECK “E” TERMINAL CONNECTION
Check if “E” terminal (alternator ground harness) is clean and tight.
Is the inspection result normal?
YES >> GO TO 4.
NO >> Repair “E” terminal connection.
4.CHECK DRIVE BELT TENSION
Check drive belt tension. Refer to EM-20, "
Checking".
Is the inspection result normal?
YES >> INSPECTION END
NO >> Repair as needed.
Unit Power source (Power supply terminals) Fuse No.
Alternator Battery (“S” terminal) 32
Combination meter Ignition switch ON (“L” terminal) 3
Revision: 2010 May2011 QX56