2006 INFINITI QX56 check engine

SC-14
STARTING SYSTEM
Revision: November 20092006 QX56
DIAGNOSTIC PROCEDURE 1
Check Starter Motor Circuit
1. CHECK POWER SUPPLY TO STARTER MOTOR
1. Remove the fuel pump fuse.
2. Crank or start the engine (where possible) until the fuel pressure is released.
3. Turn the ignition switch OFF.
4. Check that the starter motor connector F27 connection is clean and tight.
5. Check voltage between starter motor connector F27 terminal 2 and ground using a digital circuit tester.
OK or NG
OK >> GO TO 2.
NG >> Check harness between the battery and the starter motor for open circuit.
2. CHECK VOLTAGE DROP ON STARTER MOTOR CIRCUIT
Check voltage between starter motor connector F27 terminal 2 and
battery positive terminal using a digital circuit tester.
OK or NG
OK >> GO TO 3.
NG >> Check harness between the battery and the starter motor for poor continuity.
3. CHECK VOLTAGE DROP ON STARTER MOTOR GROUND CIRCUIT
Check voltage between starter motor case and battery negative ter-
minal using a digital circuit tester.
OK or NG
OK >> Starter motor ground circuit is OK. Further inspection is necessary. Refer to SC-13, "
WORK FLOW" .
NG >> Check harness between the starter motor case and ground for poor continuity.
Battery voltage should
exist.
WKIA2105E
Ignition switch in
START.
: Less than 0.5V
WKIA2106E
Ignition switch in
START. : Less than 0.2V
WKIA3437E

STARTING SYSTEMSC-15
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Revision: November 2009 2006 QX56
DIAGNOSTIC PROCEDURE 2
Check Magnetic Switch Circuit
1. CHECK POWER SUPPLY FOR MAGNETIC SWITCH
1. Remove the fuel pump fuse.
2. Crank or start the engine (where possible) until the fuel pressure is released.
3. Turn the ignition switch OFF.
4. Disconnect starter motor connector F28.
5. Check voltage between starter motor connector F28 terminal 1 and ground using a digital circuit tester.
OK or NG
OK >> GO TO 2.
NG >> Check the following.

40A fusible link (letter m , located in fuse and fusible
link box)

Ignition switch

Starter relay [within the intelligent power distribution module engine room (IPDM E/R)]

Harness for open or short
2. CHECK VOLTAGE DROP ON MAGNETIC SWITCH CIRCUIT
1. Turn the ignition switch OFF.
2. Connect starter motor connector F28.
3. Check voltage between starter motor connector F28 terminal 1 and battery positive terminal using a digital circuit tester.
OK or NG
OK >> Magnetic switch circuit is OK. Further inspection is nec- essary. Refer to SC-13, "
WORK FLOW" .
NG >> Check harness between the battery and the magnetic
switch for poor continuity.
Ignition switch in
START.
: Battery voltage
WKIA2108E
Ignition switch in
START. : Less than 1V
WKIA1792E

CHARGING SYSTEMSC-19
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Revision: November 2009 2006 QX56
Trouble Diagnoses with Battery/Starting/Charging System TesterEKS00B7J
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. Turn off all loads on the vehicle electrical system.
2. Perform battery and starting system test with Battery/Starting/
Charging system tester.
3. Press “ENTER” to begin the charging system test.
4. Start engine.
5. Press “ENTER” until “LOADS OFF REV ENGINE 5 SEC ” is dis-
played.
6. Raise and hold the engine speed at 1,500 to 2,000 rpm for about 5 seconds, then return the engine to idle.
Once the increase in engine rpm is detected, press “ENTER” to
continue.
NOTE:

If after 30 seconds an increase in engine idle speed is not
detected, “RPM NOT DETECTED” will display.

Some engines may have a higher idle initially after starting,
particularly when the engine is cold. The tester may detect
this without any other action being taken. If this occurs, con-
tinue on with the testing process. The final results will not be affected.
7. The tester now checks the engine at idle and performs the DIODE/RIPPLE check.
8. When complete, the tester will prompt you to turn on the follow- ing electrical loads.

Heater fan set to highest speed. Do not run the A/C or wind-
shield defroster.

Headlamp high beam

Rear window defogger
NOTE:
Do not run the windshield wipers or any other cyclical loads.
9. Press “ENTER” to continue.
SEL417X
SEL418X
SEL419X
SEL420X

CHARGING SYSTEMSC-23
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Revision: November 2009 2006 QX56
DIAGNOSTIC PROCEDURE 2
Check Battery Circuit
1. CHECK BATTERY CIRCUIT CONNECTION
1. Turn the ignition switch OFF.
2. Check to see if terminal 1 is clean and tight.
OK or NG
OK >> GO TO 2.
NG >> Repair terminal 1 connection. Confirm repair by performing complete Battery/Starting/Charging system test.
2. CHECK BATTERY CIRCUIT
Check voltage between generator connector E206 terminal 1 and
ground using a digital circuit tester.
OK or NG
OK >> GO TO 3.
NG >> Check the following.

140A fusible link (letter a , located in fusible link box)

Harness for open or short between generator and fus-
ible link
3. CHECK VOLTAGE DROP ON BATTERY CIRCUIT
1. Start the engine.
2. Check voltage between generator connector E206 terminal 1 and battery positive terminal using a digital circuit tester.
OK or NG
OK >> Replace the generator. Refer to SC-25, "Removal and
Installation" . Confirm repair by performing complete
Battery/Starting/Charging system test.
NG >> Check harness between the battery and the generator for poor continuity.
Battery voltage should exist.
W K I A 2 111 E
With engine running
at idle and warm.
: Less than 0.2V
WKIA2112E

SC-24
CHARGING SYSTEM
Revision: November 20092006 QX56
DIAGNOSTIC PROCEDURE 3
Check Voltage Regulator Circuit
1. CHECK VOLTAGE REGULATOR CIRCUIT CONNECTION
1. Turn the ignition switch OFF.
2. Check to see if terminal 4 is clean and tight.
OK or NG
OK >> GO TO 2.
NG >> Repair terminal 4 connection. Confirm repair by performing complete Battery/Starting/Charging system test.
2. CHECK VOLTAGE REGULATOR CIRCUIT
Check voltage between generator connector E205 terminal 4 and
ground using a digital circuit tester.
OK or NG
OK >> GO TO 3.
NG >> Check the following.

10A fuse (No. 30, located in fuse and fusible link box)

Harness for open or short between generator and
fuse
3. CHECK VOLTAGE DROP ON VOLTAGE REGULATOR CIRCUIT
1. Start the engine.
2. Check voltage between generator connector E205 terminal 4 and battery positive terminal using a digital circuit tester.
OK or NG
OK >> Replace the generator. Refer to SC-25, "Removal and
Installation" . Confirm repair by performing complete
Battery/Starting/Charging system test.
NG >> Check harness between the battery and the generator for poor continuity.
Battery voltage should exist.
WKIA2113E
With engine running
at idle and warm.
: Less than 0.2V
WKIA2114E

SE-6
SQUEAK AND RATTLE TROUBLE DIAGNOSES
Revision: November 20092006 QX56
DUPLICATE THE NOISE AND TEST DRIVE
If possible, drive the vehicle with the customer until the noise is duplicated. Note any additional information on
the Diagnostic Worksheet regarding the conditions or location of the noise. This information can be used to
duplicate the same conditions when you confirm the repair.
If the noise can be duplicated easily during the test drive, to help identify the source of the noise, try to dupli-
cate the noise with the vehicle stopped by doing one or all of the following:
1) Close a door.
2) Tap or push/pull around the area where the noise appears to be coming from.
3) Rev the engine.
4) Use a floor jack to recreate vehicle “twist”.
5) At idle, apply engine load (electrical load, half-clutch on M/T model, drive position on A/T model).
6) Raise the vehicle on a hoist and hit a tire with a rubber hammer.

Drive the vehicle and attempt to duplicate the conditions the customer states exist when the noise occurs.

If it is difficult to duplicate the noise, drive the vehicle slowly on an undulating or rough road to stress the
vehicle body.
CHECK RELATED SERVICE BULLETINS
After verifying the customer concern or symptom, check ASIST for Technical Service Bulletins (TSBs) related
to that concern or symptom.
If a TSB relates to the symptom, follow the procedure to repair the noise.
LOCATE THE NOISE AND IDENTIFY THE ROOT CAUSE
1. Narrow down the noise to a general area.To help pinpoint the source of the noise, use a listening tool (Chassis Ear: J-39570, Engine Ear: J-39565 and mechanic's stethoscope).
2. Narrow down the noise to a more specific area and identify the cause of the noise by:

removing the components in the area that you suspect the noise is coming from.
Do not use too much force when removing clips and fasteners, otherwise clips and fasteners can be bro-
ken or lost during the repair, resulting in the creation of new noise.

tapping or pushing/pulling the component that you suspect is causing the noise.
Do not tap or push/pull the component with excessive force, otherwise the noise will be eliminated only
temporarily.

feeling for a vibration with your hand by touching the component(s) that you suspect is (are) causing the
noise.

placing a piece of paper between components that you suspect are causing the noise.

looking for loose components and contact marks.
Refer to SE-7, "
Generic Squeak and Rattle Troubleshooting" .
REPAIR THE CAUSE

If the cause is a loose component, tighten the component securely.

If the cause is insufficient clearance between components:
–separate components by repositioning or loosening and retightening the component, if possible.
–insulate components with a suitable insulator such as urethane pads, foam blocks, felt cloth tape or ure-
thane tape. A NISSAN Squeak and Rattle Kit (J-43980) is available through your authorized NISSAN
Parts Department.
CAUTION:
Do not use excessive force as many components are constructed of plastic and may be damaged.
Always check with the Parts Department for the latest parts information.
The following materials are contained in the NISSAN Squeak and Rattle Kit (J-43980). Each item can be
ordered separately as needed.
URETHANE PADS [1.5 mm (0.059 in) thick]
Insulates connectors, harness, etc.
76268-9E005: 100× 135 mm (3.94×5.31 in)/76884-71L01: 60 ×85 mm (2.36 ×3.35 in)/76884-71L02: 15 ×25
mm (0.59 ×0.98 in)
INSULATOR (Foam blocks)
Insulates components from contact. Can be used to fill space behind a panel.
73982-9E000: 45 mm (1.77 in) thick, 50 ×50 mm (1.97 ×1.97 in)/73982-50Y00: 10 mm (0.39 in) thick,
50 ×50 mm (1.97 ×1.97 in)
INSULATOR (Light foam block)

TF-1
TRANSFER
D DRIVELINE/AXLE
CONTENTS
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Revision: November 2009 2006 QX56
PRECAUTIONS .....................................................
..... 4
Precautions for Supplemental Restraint System
(SRS) “AIR BAG” and “SEAT BELT PRE-TEN-
SIONER” ............................................................. ..... 4
Precautions for Transfer Assembly and Transfer
Control Unit Replacement ................................... ..... 4
METHOD FOR POSITION ADJUSTMENT ...... ..... 4
Precautions ......................................................... ..... 4
Service Notice .......................................................... 5
PREPARATION ...................................................... ..... 6
Special Service Tools .......................................... ..... 6
Commercial Service Tools ................................... ..... 9
NOISE, VIBRATION AND HARSHNESS (NVH)
TROUBLESHOOTING ........................................... ... 10
NVH Troubleshooting Chart ................................ ... 10
TRANSFER FLUID ................................................ ....11
Replacement ....................................................... .... 11
DRAINING ........................................................ .... 11
FILLING ............................................................ .... 11
Inspection ............................................................ .... 11
FLUID LEAKAGE AND FLUID LEVEL ............. .... 11
ALL-MODE 4WD SYSTEM ................................... ... 12
Cross-section View ............................................. ... 12
Power Transfer .................................................... ... 13
POWER TRANSFER DIAGRAM ..................... ... 13
POWER TRANSFER FLOW ............................ ... 14
System Description ............................................. ... 15
CONTROL SYSTEM ........................................ ... 15
TRANSFER MOTOR ....................................... ... 16
WAIT DETECTION SWITCH ........................... ... 17
NEUTRAL-4LO SWITCH ................................. ... 17
ATP SWITCH ................................................... ... 17
2-4WD SHIFT SOLENOID VALVE ................... ... 17
CLUTCH PRESSURE SOLENOID VALVE ...... ... 18
LINE PRESSURE SWITCH ............................. ... 18
CLUTCH PRESSURE SWITCH ....................... ... 18
TRANSFER FLUID TEMPERATURE SENSOR ... 18
TRANSFER CONTROL UNIT .......................... ... 18
TRANSFER CONTROL DEVICE ..................... ... 18
4WD SHIFT SWITCH AND INDICATOR LAMP ... 184WD WARNING LAMP ....................................
... 19
ATP WARNING LAMP ...................................... ... 19
System Diagram ..................................................... 19 COMPONENTS FUNCTION ............................ ... 20
CAN Communication .............................................. 20 SYSTEM DESCRIPTION ................................. ... 20
TROUBLE DIAGNOSIS ......................................... ... 21
How to Perform Trouble Diagnosis ...................... ... 21
BASIC CONCEPT ............................................ ... 21
Location of Electrical Parts .................................. ... 22
Circuit Diagram ....................................................... 23
Wiring Diagram — T/F — .................................... ... 24
Inspections Before Trouble Diagnosis ................. ... 32
TRANSFER FLUID CHECK ............................. ... 32
PREPARATION FOR ROAD TEST .................. ... 32
CHECK BEFORE ENGINE IS STARTED ........ ... 32
CHECK AT IDLE ............................................... ... 32
CRUISE TEST ..................................................... 33
Trouble Diagnosis Chart for Symptoms ............... ... 34
Transfer Control Unit Input/Output Signal Refer-
ence Values ......................................................... ... 35
TRANSFER CONTROL UNIT INSPECTION
TABLE .............................................................. ... 35
CONSULT-II Function (ALL MODE AWD/4WD) .. ... 44
FUNCTION ....................................................... ... 44
CONSULT-II SETTING PROCEDURE ............. ... 44
SELF-DIAG RESULT MODE ............................ ... 45
DATA MONITOR MODE ................................... ... 47
WORK SUPPORT ............................................ ... 49
Self-diagnostic Procedure ................................... ... 50
SELF-DIAGNOSTIC PROCEDURE (WITH
CONSULT-II) .................................................... ... 50
SELF-DIAGNOSTIC PROCEDURE (WITHOUT
CONSULT-II) .................................................... ... 50
ERASE SELF-DIAGNOSIS .............................. ... 53
TROUBLE DIAGNOSIS FOR SYSTEM ................. ... 54
Power Supply Circuit For Transfer Control Unit ... ... 54
CONSULT-II REFERENCE VALUE IN DATA
MONITOR MODE ............................................. ... 54
TRANSFER CONTROL UNIT TERMINALS AND

TF-4
PRECAUTIONS
Revision: November 20092006 QX56
PRECAUTIONSPFP:00001
Precautions for Supplemental Restraint System (SRS) “AIR BAG” and “SEAT
BELT PRE-TENSIONER”
EDS002H3
The Supplemental Restraint System such as “AIR BAG” and “SEAT BELT PRE-TENSIONER ”, used along
with a front seat belt, helps to reduce the risk or severity 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 and SB section of this Service Man-
ual.
WARNING:

To avoid rendering the SRS inoperative, which could increase the risk of personal injury or death
in the event of a collision which would result in air bag inflation, all maintenance must be per-
formed by an authorized NISSAN/INFINITI dealer.

Improper maintenance, including incorrect removal and installation of the SRS, can lead to per-
sonal injury caused by unintentional activation of the system. For removal of Spiral Cable and Air
Bag Module, see the SRS section.

Do not use electrical test equipment on any circuit related to the SRS unless instructed to in this
Service Manual. SRS wiring harnesses can be identified by yellow and/or orange harnesses or
harness connectors.
Precautions for Transfer Assembly and Transfer Control Unit ReplacementEDS002H4
When replacing transfer assembly or transfer control unit, check the 4WD shift indicator lamp as follows.
1. Turn ignition switch “ON ”.
2. Check 4WD shift indicator lamp is turned ON for approx. 1 second.

If OK, the position between transfer assembly and transfer control unit is correct.

If NG, the position is different between transfer assembly and transfer control unit.
Adjust the position between transfer assembly and transfer control unit. Refer to TF-4, "
METHOD FOR
POSITION ADJUSTMENT" .
METHOD FOR POSITION ADJUSTMENT
1. Start engine. Run the engine for at least 10 seconds.
2. Stop vehicle and move A/T selector lever to “N” position with brake pedal depressed. Stay in "N" for at
least 2 seconds.
3. Turn 4WD shift switch to “2WD ” position. Stay in "2WD" for at least 2 seconds.
4. Turn ignition switch “ OFF”.
5. Start engine.
6. Erase self-diagnosis. Refer to TF-47, "
How to Erase Self-diagnostic Results" (with CONSULT-II) or TF-
53, "ERASE SELF-DIAGNOSIS" (without CONSULT-II).
7. Check 4WD shift indicator lamp. Refer to TF-32, "
CHECK BEFORE ENGINE IS STARTED" .
If 4WD shift indicator lamp does not indicate "2WD", install new transfer control unit and retry the above
check.
PrecautionsEDS002H5

Before connecting or disconnecting the transfer control
unit harness connector, turn ignition switch “OFF” and dis-
connect battery ground cable. Failure to do so may damage
the transfer control unit. Battery voltage is applied to trans-
fer control unit even if ignition switch is turned “OFF”.
SEF289H