2008 INFINITI QX56 battery volt

CHG-8
< FUNCTION DIAGNOSIS >
CHARGING SYSTEM
FUNCTION DIAGNOSIS
CHARGING SYSTEM
System DiagramINFOID:0000000001696178
System DescriptionINFOID:0000000001696179
The generator provides DC voltage to operate the vehicle's electrical system and to keep the battery charged.
The voltage output is controlled by the IC regulator.
Component DescriptionINFOID:0000000001696180
ALMIA0207GB
Component part Description
Generator Terminal “1”
Refer to CHG-13, "
Description".
Terminal “2” Refer to CHG-15, "
Description".
Terminal “3” Refer to CHG-14, "
Description".
Terminal “4” Used for the power generation voltage variable control system.
Refer to
CHG-9, "
System Description".
Combination meter (C harge warning lamp) The IC regulator warning function activates to illuminate the
charge warning lamp if any of the following symptoms occur while
generator is operating:
• Excessive voltage is produced.
• No voltage is produced.
IPDM E/R Used for the power generation voltage variable control system.
Refer to
CHG-9, "
System Description".
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
S TERMINAL CIRCUITCHG-15
< COMPONENT DIAGNOSIS >
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S TERMINAL CIRCUIT
DescriptionINFOID:0000000001696190
The output voltage of the generator is controlled by the IC
regulator at terminal “3” (S) detecting the input volt-
age. Terminal “3” circuit detects the battery voltage to adjust the generator output voltage with the IC regulator.
Diagnosis ProcedureINFOID:0000000001696191
1.CHECK VOLTAGE REGULATOR CIRCUIT CONNECTION
Check to see if connector E205 terminal 3 is clean and tight.
Is the inspection result normal?
YES >> GO TO 2
NO >> Repair terminal connection. Confirm repair by performing complete Starting/Charging system test.
Refer to Technical Service Bulletin.
2.CHECK VOLTAGE REGULATOR CIRCUIT
Check voltage between generator harness connector E205 terminal
3 and ground.
Does battery voltage exist?
YES >> Refer to CHG-5, "Work Flow".
NO >> Check harness for open between generator and fuse. 3 - ground
Battery voltage
ALMIA0201ZZ
Revision: March 2010 2008 QX56

REAR WINDOW DEFOGGER RELAYDEF-9
< COMPONENT DIAGNOSIS >
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REAR WINDOW DEFOGGER RELAY
DescriptionINFOID:0000000001735612
Power is supplied to the rear window defogger with BCM control.
Component Function CheckINFOID:0000000001735613
1. CHECK REAR WINDOW DEFOGGER RELAY POWER SUPPLY CIRCUIT
Check that an operation noise of rear window defogger re lay (located in IPDM E/R) can be heard when turning
the rear window defogger switch ON.
Is the inspection result normal?
YES >> Rear window defogger relay power supply circuit is OK.
NO >> Refer to DEF-9, "
Diagnosis Procedure".
Diagnosis ProcedureINFOID:0000000001735614
1.CHECK FUSES
Check if any of the following fuses in the IPDM E/R are blown.
Is the inspection result normal?
YES >> GO TO 2
NO >> If fuse is blown, be sure to eliminate cause of malfunction before installing new fuse.
2. CHECK REAR WINDOW DEFOGGER RELAY POWER SUPPLY CIRCUIT
1. Turn ignition switch ON.
2. Check voltage between IPDM E/R connector and ground.
Is the inspection result normal?
YES >> Replace IPDM E/R. Refer to PCS-34, "Removal and Installation of IPDM E/R".
NO >> GO TO 3
3. CHECK INTERMITTENT INCIDENT
Check intermittent incident.
Refer to GI-38, "
Intermittent Incident"
Is the inspection result normal?
YES >> Check the following.
• Battery power supply circuit.
• IPDM E/R.
NO >> Repair or replace the malfunctioning parts.
COMPONENT PARTS AMPEREFUSE NO.
IPDM E/R 15A46
IPDM E/R 15A47
Te r m i n a l s
Condition of rear
window defogger
switch Voltage (V)
(Approx.)
(+)
(–)
IPDM E/R con-
nector Te r m i n a l
E124 60 Ground ON Battery voltage
OFF 0
LIIA2190E
Revision: March 2010 2008 QX56

DEF-10
< COMPONENT DIAGNOSIS >
REAR WINDOW DEFOGGER POWER SUPPLY AND GROUND CIRCUIT
REAR WINDOW DEFOGGER POWER SUPPLY AND GROUND CIRCUIT
DescriptionINFOID:0000000001735615
Heats the heating wire with the power supply from the rear window defogger relay to prevent the rear window
from fogging up.
Component Function CheckINFOID:0000000001735616
1. CHECK REAR WINDOW DEFOGGER
Check that the heating wire of rear window defogger is heated when turning the rear window defogger switch
ON.
Is the inspection result normal?
YES >> Rear window defogger is OK.
NO >> Refer to DEF-10, "
Diagnosis Procedure".
Diagnosis ProcedureINFOID:0000000001735617
1. CHECK POWER SUPPLY CIRCUIT
1. Turn ignition switch ON.
2. Check voltage between rear window defogger connector and ground.
Is the inspection result normal?
YES >> GO TO 2
NO >> GO TO 3
2. CHECK GROUND CIRCUIT
1. Turn ignition switch OFF.
2. Disconnect rear window defogger.
3. Check continuity between rear window defogger connector and ground.
Is the inspection result normal?
YES >> GO TO 4
NO >> Repair or replace harness.
3. CHECK HARNESS CONTINUITY
Te r m i n a l s Condition of rear window
defogger switch Voltage (V)
(Approx.)
(+)
(–)
Rear window
defogger
connector Te r m i n a l
D406 1 Ground ON Battery voltage
OFF 0
ALLIA0177ZZ
Rear window defogger connector Terminal
GroundContinuity
D604 2 Yes
ALLIA0178ZZ
Revision: March 2010 2008 QX56

DEF-12
< COMPONENT DIAGNOSIS >
DOOR MIRROR DEFOGGER LH
DOOR MIRROR DEFOGGER LH
DescriptionINFOID:0000000001735623
Heats the heating wire with the power supply from the rear window defogger relay to prevent the door mirror
from fogging up.
Component Function CheckINFOID:0000000001735624
1. CHECK DOOR MIRROR DEFOGGER LH
Check that heating wire of door mirror defogger LH is heated when turning the rear window defogger switch
ON.
Is the inspection result normal?
YES >> Door mirror defogger is OK.
NO >> Refer to DEF-12, "
Diagnosis Procedure".
Diagnosis ProcedureINFOID:0000000001735625
1. CHECK POWER SUPPLY
Check if the following fuse in the IPDM E/R is blown.
Is the inspection result normal?
YES >> GO TO 2
NO >> If fuse is blown, be sure to eliminate cause of malfunction before installing new fuse.
2. CHECK DOOR MIRROR DE FOGGER POWER SUPPLY CIRCUIT
Check voltage between IPDM E/R connector and ground.
Is the inspection result normal?
YES >> GO TO 3
NO >> Replace IPDM E/R. Refer to PCS-34, "
Removal and Installation of IPDM E/R".
3. CHECK DOOR MIRROR DEFOGGER POWER SUPPLY CIRCUIT 2
1. Turn ignition switch OFF.
2. Disconnect door mirror LH.
3. Turn ignition switch ON.
4. Check voltage between door mirror LH connector and ground.
Is the inspection result normal?
YES >> GO TO 4
COMPONENT PARTS AMPEREFUSE NO.
IPDM E/R 15A43
ConnectorTe r m i n a l
ConditionVoltage (V)
(Approx.)
(+) (-)
E120 23 Ground Rear window defogger
switch ON
Battery voltage
Rear window defogger
switch OFF 0
LIIA2049E
ConnectorTe r m i n a l
ConditionVoltage (V)
(Approx.)
(+) (-)
D4 10 Ground Rear window defogger
switch ON
Battery voltage
Rear window defogger
switch OFF 0
LIIA1456E
Revision: March 2010
2008 QX56