2011 INFINITI QX56 engine

CCS
U1520 4WD CAN 3CCS-157
< DTC/CIRCUIT DIAGNOSIS > [ICC]
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U1520 4WD CAN 3
DTC LogicINFOID:0000000006224436
DTC DETECTION LOGIC
NOTE:
If DTC “U1520” is detected along with DTC “U 1000”, first diagnose the DTC “U1000”. Refer to CCS-145,
"ADAS CONTROL UNIT : DTC Logic".
DTC CONFIRMATION PROCEDURE
1.PERFORM DTC CONFIRMATION PROCEDURE
1. Start the engine.
2. Turn the MAIN switch of ICC system ON.
3. Perform “All DTC Readi ng” with CONSULT-III.
4. Check if the “U1520” is detected as the current ma lfunction in “Self Diagnostic Result” of “ICC/ADAS”.
Is
“U1520” detected as the current malfunction?
YES >> Refer to CCS-157, "Diagnosis Procedure".
NO >> Refer to GI-40, "
Intermittent Incident".
Diagnosis ProcedureINFOID:0000000006224437
1.CHECK SELF-DIAGNOSIS RESULTS
Check if “U1000” is detected other than “U1520” in “Self Diagnostic Result” of “ICC/ADAS”.
Is
“U1000” detected?
YES >> Perform the CAN communicati on system inspection. Repair or replace the malfunctioning parts.
Refer to CCS-145, "
ADAS CONTROL UNIT : DTC Logic".
NO >> GO TO 2.
2.CHECK TRANSFER CONTROL UNIT SELF-DIAGNOSIS RESULTS
Check if any DTC is detected in “Self Diagnostic Result” of “ALL MODE AWD/4WD”.
Is any DTC detected?
YES >> Perform diagnosis on the detected DTC and repair or replace the malfunctioning parts. Refer to
DLN-29, "
DTC Index".
NO >> Replace the ADAS control unit. Refer to DAS-63, "
Removal and Installation".
DTC
(On board dis-
play) Trouble diagnosis name DTC detecting condition Possible causes
U1520 (176) 4WD CAN CIRC 3 ADAS control unit detects an error signal that is
received from transfer control unit via CAN
communication
Transfer control unit
Revision: 2010 May2011 QX56

CCS
MAIN SWITCH DOES NOT TURN ON, MAIN SWITCH DOES NOT TURN OFF
CCS-161
< SYMPTOM DIAGNOSIS > [ICC]
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MAIN SWITCH DOES NOT TURN ON, MAIN SWITCH DOES NOT TURN
OFF
DescriptionINFOID:0000000006224441
MAIN switch does not turn ON
 ICC system display does not appear ev en when MAIN switch is pressed.
MAIN switch does not turn OFF When ICC system display is ON, display does not turn OFF even if MAIN switch is pressed.
NOTE:
When ICC system warning lamp illuminates, perform t he self-diagnosis of ICC system, and then repair or
replace the malfunctioning parts.
Diagnosis ProcedureINFOID:0000000006224442
1.MAIN SWITCH INSPECTION
1. Start the engine.
2. Check that “MAIN SW” and “CRUISE LAMP” operate no rmally in “DATA MONITOR” of “ICC/ADAS” with
CONSULT-III.
Is the inspection result normal?
YES >> GO TO 2.
NO >> GO TO 4.
2.CHECK COMBINATION METER
Check that “CRUISE IND” operates normally in “DATA MONITOR” of “METER/M&A”.
Is the inspection result normal?
YES >> GO TO 3.
NO >> GO TO 4.
3.PERFORM SELF-DIAGNOSIS OF COMBINATION METER
1. Perform “Self Diagnostic Re sult” of “METER/M&A”.
2. Check if DTC is detected. Refer to MWI-43, "
DTC Index".
Is any DTC detected?
YES >> Repair or replace malfunctioning parts.
NO >> GO TO 4.
4.PERFORM SELF-DIAGNOSIS RESULTS OF ICC SYSTEM
1. Perform “All DTC Reading”.
2. Check if the “U1000” is detected in self-diagnosis results of “ICC/ADAS”.
Is
“U1000” detected?
YES >> GO TO 5.
NO >> GO TO 6.
5.CAN COMMUNICATIONS INSPECTION
Check the CAN communication and repair or replace malfunctioning parts. Refer to CCS-145, "
ADAS CON-
TROL UNIT : DTC Logic".
>> INSPECTION END
6.CHECK ICC STEERING SWITCH
Check the ICC steering switch. Refer to CCS-177, "
Exploded View".
>> INSPECTION END
Revision: 2010 May2011 QX56

CCS-162
< SYMPTOM DIAGNOSIS >[ICC]
ICC SYSTEM CANNOT BE SET
(MAIN SWITCH TURNS ON/OFF)
ICC SYSTEM CANNOT BE SET (MAIN SWITCH TURNS ON/OFF)
DescriptionINFOID:0000000006224443
The MAIN switch can be turned ON/OFF, but the ICC system cannot be set even if the SET/COAST switch is
pressed.
NOTE:
The system cannot be set in the following case.
 When the vehicle ahead is not detected bel ow the speed of 32 km/h (20 MPH).
 When the selector lever is not in the “D” position or manual mode.
 When the front wipers are operating at HI.
(If the vehicle is equipped with a rain sensing auto-wi per, the system may cancel when the wipers are set to
AUTO)
 When the brake pedal is depressed.
 When driving into a strong light (i.e., sunlight).
 When the VDC is turned OFF.
 When ABS or VDC (including the TCS) operates.
 When a wheel slips.
 When SNOW mode switch is turned ON.
 When ABS warning lamp is ON.
 When 4WD shift switch is not AUTO position.
Diagnosis ProcedureINFOID:0000000006224444
1.CHECK CAUSE OF AUTOMATIC CANCELLATION
Check if there is the cancellation cause in the “CAUSE OF AUTO-CANCEL” on “WORK SUPPORT” of “ICC/
ADAS” with CONSULT-III.
Is it displayed?
Not displayed>>GO TO 2.
“OPE SW VOLT CIRC”>>Refer to CCS-94, "
DTC Logic".
“VHCL SPD UNMATCH”>>Refer to CCS-87, "
DTC Logic".
“IGN LOW VOLT”>>Refer to CCS-85, "
ADAS CONTROL UNIT : DTC Logic".
“ECM CIRCUIT”>>Refer to CCS-103, "
DTC Logic".
“CAN COMM ERROR”>>Refer to CCS-145, "
ADAS CONTROL UNIT : DTC Logic".
“ICC SENSOR CAN COMM ERR”>>Refer to CCS-137, "
DTC Logic".
“ABS/TCS/VDC CIRC”>>Refer to CCS-89, "
DTC Logic".
“ECD CIRCUIT”>>Refer to CCS-115, "
DTC Logic".
2.PERFORM THE SELF-DIAGNOSIS
1. Perform “All DTC Reading”.
2. Check if any DTC is detected in “Self Diagnosti c Result” of “ICC/ADAS”” of “LASER”. Refer to CCS-50,
"DTC Index" (ICC/ADAS) or CCS-55, "DTC Index" (LASER).
Is any DTC detected?
YES >> GO TO 3.
NO >> GO TO 4.
3.REPAIR OR REPLACE MALFUNCTIONING PARTS
Repair or replace malfunctioning parts identified by the self-diagnosis result.
>> GO TO 6.
4.CHECK EACH SWITCH AND VEHICLE SPEED SIGNAL
1. Start the engine.
2. Check that the following items operate no rmally in “DATA MONITOR” of “ICC/ADAS”.
- “VHCL SPEED SE”
- “D RANGE SW”
- “SET/COAST SW”
- “BRAKE SW”
-“WIPER SW”
Revision: 2010 May2011 QX56

CCS-164
< SYMPTOM DIAGNOSIS >[ICC]
ICC STEERING SWITCH (OTHER THAN
MAIN SWITCH) DOES NOT FUNCTION
ICC STEERING SWITCH (OTHER THAN MAIN SWITCH) DOES NOT
FUNCTION
DescriptionINFOID:0000000006224445
MAIN switch can be turned ON/OFF, but the operati on of RESUME/ACCELERATE switch, CANCEL switch,
and DISTANCE switch cannot be performed during ICC system operation.
NOTE:
Resume is not accepted when the following condition is met.
 When the MAIN switch is turned OFF once.
The set distance change is not accepted when any of the following condition is met.
 When the DCA system is turned ON.
Diagnosis ProcedureINFOID:0000000006224446
1.CHECK EACH SWITCH
1. Start the engine.
2. Check that each switch operates normally on “DAT A MONITOR” of “ICC/ADAS” with CONSULT-III.
- “RESUME/ACC SW”
- “CANCEL SW”
- “DISTANCE SW”
Is the inspection result normal?
YES >> GO TO 5.
NO >> GO TO 2.
2.PERFORM ALL OF THE SELF-DIAGNOSIS ITEMS
1. Perform “All DTC Reading”.
2. Check if the “U1000” is detected in “Self Diagnostic Result” of “ICC/ADAS”.
Is
“U1000” detected?
YES >> GO TO 3.
NO >> GO TO 4.
3.CAN COMMUNICATIONS INSPECTION
Check the CAN communication and repair or replace malfunctioning parts. Refer to CCS-145, "
ADAS CON-
TROL UNIT : DTC Logic".
>> INSPECTION END
4.CHECK ICC STEERING SWITCH
Check the ICC steering switch. Refer to CCS-95, "
Component Inspection".
>> GO TO 6.
5.REPLACE ADAS CONTROL UNIT
Replace the ADAS control unit. Refer to DAS-63, "
Removal and Installation".
>> GO TO 6.
6.CHECK ICC SYSTEM
1. Erase the self-diagnosis results, and then perfo rm “All DTC Reading” again after performing the action
test. (Refer to CCS-77, "
Description" for action test.)
2. Check that the ICC system is normal.
>> INSPECTION END
Revision: 2010 May2011 QX56

CCS-168
< SYMPTOM DIAGNOSIS >[ICC]
DRIVING FORCE IS HUNTING
DRIVING FORCE IS HUNTING
DescriptionINFOID:0000000006224451
The vehicle causes hunting when the ICC system is active.
Diagnosis ProcedureINFOID:0000000006224452
1.PERFORM SELF-DIAGNOSIS OF ECM
1. Perform “All DTC Reading” with CONSULT-III.
2. Check if the DTC is detected in self-diagnosis results of “ENGINE”. Refer to EC-98, "
DTC Index".
Is any DTC detected?
YES >> GO TO 3.
NO >> GO TO 2.
2.CHECK ICC SENSOR BODY WINDOW
1. Check the vehicle driving conditions. Refer to CCS-169, "
Description".
2. Check the ICC sensor body window for contaminat ion, foreign materials, or cracks. Refer to CCS-169,
"Diagnosis Procedure".
>> INSPECTION END
3.REPAIR OR REPLACE MALFUNCTIONING PARTS
Repair or replace malfunctioning parts identified by the self-diagnosis result.
>> GO TO 4.
4.CHECK ICC SYSTEM
1. Erase the self-diagnosis results, and then perfo rm “All DTC Reading” again after performing the action
test. (Refer to CCS-77, "
Description" for action test.)
2. Check that the ICC system is normal.
>> INSPECTION END
Revision: 2010 May2011 QX56

CHG
PRECAUTIONSCHG-3
< PRECAUTION >
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PRECAUTION
PRECAUTIONS
Precaution for Supplemental
Restraint System (SRS) "AIR BAG" and "SEAT BELT
PRE-TENSIONER"
INFOID:0000000006274854
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 severi ty 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 whether the front occupants are belted or unbelted.
Information necessary to service the system safely is included in the “SRS AIR BAG” and “SEAT BELT” of this
Service Manual.
WARNING:
• To avoid rendering the SRS inoper ative, which could increase the risk of personal injury or death in
the event of a collision that would result in air ba g 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 unintentional act ivation of the system. For removal of Spiral Cable and Air Bag
Module, see the “SRS AIR BAG”.
 Do not use electrical test equipm ent on any circuit related to the SRS unless instructed to in this
Service Manual. SRS wiring harnesses can be identi fied 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 Air Bag Diagnosis Sensor Unit or other Air Bag System sensors with the
ignition ON or engine running, DO NOT use air or electric 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 minutes before performing any service.
Precaution Necessary for Steering Wh eel Rotation after Battery Disconnect
INFOID:0000000006274855
NOTE:
 Before removing and installing any control units, first tu rn the push-button ignition switch to the LOCK posi-
tion, then disconnect both battery cables.
 After finishing work, confirm that all control unit connectors are connected properly, then re-connect both
battery cables.
 Always use CONSULT-III to perform self-diagnosis as a part of each function inspection after finishing work.
If a DTC is detected, perform trouble diagnos is according to self-diagnosis results.
For vehicle with steering lock unit, if the battery is disconnected or discharged, the steering wheel will lock and
cannot be turned.
If turning the steering wheel is required with the batte ry disconnected or discharged, follow the operation pro-
cedure below before starting the repair operation.
OPERATION PROCEDURE
1. Connect both battery cables. NOTE:
Supply power using jumper cables if battery is discharged.
2. Turn the push-button ignition switch to ACC position. (At this time, the steering lock will be released.)
3. Disconnect both battery cables. The steering lock wil l remain released with both battery cables discon-
nected and the steering wheel can be turned.
4. Perform the necessary repair operation.
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

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