engine INFINITI QX56 2007 Factory Service Manual

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ENGINE MAINTENANCE
Changing Spark Plugs
INFOID:0000000003533873
REMOVAL
1. Remove the ignition coil. Refer to EM-28, "Removal and Installation" .
2. Remove the spark plug using suitable tool.
INSPECTION AFTER REMOVAL
• Do not use a wire brush for cleaning.
• If the spark plug tip is covered with carbon, a spark plug cleaner may be used.
1. Ignition coil 2. Spark plug
WBIA0796E
SEM294A
SMA773C
Cleaner air pressure
: Less than 588 kPa (5.9 bar, 6 kg/cm2 , 85 psi)
Cleaning time : Less than 20 seconds

ENGINE MAINTENANCE
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• Checking and adjusting plug gap is not required between change
intervals.
INSTALLATION
Installation is in the reverse order of removal.
CAUTION:
Do not drop or shock spark plug.
Checking EVAP Vapor LineINFOID:0000000003533874
1. Visually inspect the EVAP vapor lines for improper attachment, cracks, damage, loose connections, chaf-
ing, or deterioration.
2. Inspect the vacuum relief valve of the fuel tank filler cap for clogging and sticking.
Refer to EC-37, "
How to Detect Fuel Vapor Leakage" .
SMA806CA
MakeNGK
Standard typePLFR5A-11
Gap (Nominal) 1.1 mm (0.043 in)

CHASSIS AND BODY MAINTENANCE
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6. Install the lower glove box in the instrument panel and secure it
with the two hinge pins.
Checking Exhaust SystemINFOID:0000000003533876
Check exhaust pipes, muffler and mounting for improper attachment,
leaks, cracks, damage, loose connections, chafing or deterioration.
Checking Automatic Transmission Fluid (ATF)INFOID:0000000003533877
1. Remove the ATF level gauge bolt.
2. Before driving, the ATF level can be checked at ATF tempera-
tures of 30° to 50°C (86° to 122°F) using the “COLD” range on
the ATF level gauge as follows:
a. Park the vehicle on a level surface and set the parking brake.
b. Start the engine and move the selector lever through each gear
position. Shift the selector lever into the “P” position.
c. Check the ATF level with the engine idling.
d. Remove the ATF level gauge and wipe it clean with a lint-free
paper.
CAUTION:
When wiping the ATF from the ATF level gauge, always use
a lint-free paper, not a cloth.
e. Re-insert the ATF level gauge into the charging pipe until the
cap contacts the top of the charging pipe as shown.
CAUTION:
To check ATF level, insert the ATF level gauge until the cap
contacts the top of the charging pipe, with the gauge
reversed from the normal inserted position.
f. Remove the ATF level gauge and note the ATF level. If the ATF
level is at low side of range, add ATF to the transmission
through the charging pipe.
CAUTION:
Do not overfill the transmission with ATF.
g. Install the ATF level gauge and the ATF level gauge bolt.
3. Warm up the engine.
4. Check for any ATF leaks.
WLIA0027E
SMA211A
WLIA0014E
ATF level gauge bolt : Refer to AT-228, "Component" .
SCIA1684E

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10. Tighten the level gauge bolt to specification.
Changing Automatic Transmission Fluid (ATF)INFOID:0000000003533878
1. Drive the vehicle to warm up the ATF to 80° C (176° F).
2. Stop the engine.
3. Remove the ATF level gauge bolt.
4. Drain the ATF from the drain plug hole and then install the drain
plug with a new gasket. Refill the transmission with new ATF.
Always refill with the same volume as the drained ATF. Use the
ATF level gauge to check the ATF level as shown. Add ATF as
necessary.
• To flush out the old ATF from the coolers, pour new ATF into the charging pipe with the engine idling and
at the same time drain the old ATF from the auxiliary transmission oil cooler hose return line.
• When the color of the ATF coming out of the auxiliary transmission oil cooler hose return line is about
the same as the color of the new ATF, flushing out the old ATF is complete. The amount of new trans-
mission ATF used for flushing should be 30% to 50% increase of the specified capacity.
CAUTION:
• Use only the specified ATF. Do not mix with other fluids.
• Using an ATF other than the specified ATF will cause deterioration in driveability and automatic
transmission durability, and may damage the automatic transmission, which is not covered by
the warranty.
• When filling the transmission with ATF, do not spill the ATF on any heat generating parts such as
the exhaust manifold.
• Do not reuse the drain plug gasket.
5. Install the ATF level gauge in the ATF charging pipe and tighten the level gauge bolt to specification.
6. Drive the vehicle to warm up the ATF to 80° C (176° F).
7. Check the ATF level and condition. Refer to AT-13, "
Checking Automatic Transmission Fluid (ATF)". If the
ATF is still dirty, repeat steps 2 through 5.
Changing Transfer FluidINFOID:0000000003533879
DRAINING
1. Stop the engine.Level gauge bolt: : Refer to AT-228, "
Component" .
Drain plug : Refer to AT-228, "
Component" .
WLIA0014E
ATF type and capacity : Refer to MA-10, "Fluids and Lubricants" .
Drain plug : Refer to AT-228, "
Component" .
Level gauge bolt : Refer to AT-228, "
Component".

MA-24
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CHASSIS AND BODY MAINTENANCE
2. Remove the drain plug and gasket to drain the transfer fluid as
shown.
3. Install the new gasket on the drain plug and install the drain plug
in the transfer. Tighten the drain plug to specification.
CAUTION:
Do not reuse the gasket.
FILLING
1. Remove the filler plug and gasket.
2. Fill with new specified fluid until the fluid level reaches the spec-
ified limit near the filler plug mounting hole as shown.
CAUTION:
Carefully fill the transfer with fluid. Filling should take
approximately three minutes.
3. Leave the vehicle for three minutes and then check the fluid
level again as shown.
4. Install the new gasket on the filler plug and install the filler plug
in the transfer. Tighten the filler plug to specification.
CAUTION:
Do not reuse the gasket.
Checking Transfer FluidINFOID:0000000003533880
FLUID LEAKAGE AND FLUID LEVEL
1. Check for any fluid leaks from the transfer assembly or around it and correct as necessary.
2. Remove the filler plug to check the fluid level at the filler plug
mounting hole as shown.
CAUTION:
Do not start the engine while checking the fluid level.
3. Install the new gasket on the filler plug and install the filler plug
in the transfer. Tighten the filler plug to specification.
CAUTION:
Do not reuse the gasket.
Checking Propeller ShaftINFOID:0000000003533881
Check the front and rear propeller shafts for damage, dents, and cracks. Check the joints for looseness and
any damage. Repair or replace as necessary.
Checking Final Drive OilINFOID:0000000003533882
1. Remove the filler plug.Drain plug : Refer to AT-228, "
Component".
SMA444B
Fluid capacity and grade : Refer to MA-10, "Fluids
and Lubricants" .
Filler plug : Refer to AT-228, "
Component" .
SMA439B
Filler plug : Refer to AT-228, "Component" .
SMA439B

CHASSIS AND BODY MAINTENANCE
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5. Start wheel balancer. Make sure that inner and outer residual imbalance values are 5 g (0.18 oz) each or
below.
Wheel Balance (Maximum Allowable Imbalance)
• If either residual imbalance value exceeds 5 g (0.18 oz), repeat installation procedures.
Tire RotationINFOID:0000000003533885
1. Rotate the tires on each side from front to back as shown.
2. Adjust the tire pressure to specification. Refer to WT-28, "
Tire" .
3. After the tire rotation, retighten the wheel nuts after the vehicle
has been driven for 1,000 km (600 miles), and also after a wheel
and tire have been installed such as after repairing a flat tire.
Checking Brake Fluid Level and LeaksINFOID:0000000003533886
• Check the brake fluid level in the reservoir tank. It should be
between the “MAX” and “MIN” lines on the reservoir tank.
• If the fluid level is extremely low, check the brake system.
• If the brake warning lamp comes on when the fluid is at the correct
level, check the brake fluid level switch and the parking brake
switch.
CheckingBrake Line and CablesINFOID:0000000003533887
1. Check the brake lines and hoses for cracks, deterioration, and
other damage. Replace any damaged parts.
CAUTION:
If brake fluid leaks are visible around the brake line joints,
retighten the joint, or replace damaged parts as necessary.
2. Check for brake fluid leaks by fully depressing brake pedal while
engine is running.
Checking Disc BrakeINFOID:0000000003533888
ROTOR
Maximum allowable imbalanceDynamic (At rim flange) 5 g (0.18 oz) (one side)
Static 10 g (0.35 oz)
Wheel nuts : Refer to WT-6 .
AMA159
WFIA0173E
SBR389C

CHASSIS AND BODY MAINTENANCE
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• Check the power steering fluid level with the engine off.
• Check fluid level on reservoir. Use “HOT” range at fluid tempera-
tures of 50° to 80°C (122° to 176°F). Use “COLD” range at fluid
temperatures of 0° to 30°C (32° to 86°F).
CAUTION:
• Do not overfill.
• Refer to MA-10, "
Fluids and Lubricants" .
CHECKING LINES
• Check lines for improper attachment, leaks, cracks, damage, loose
connections, chafing, and deterioration.
Checking Axle and Suspension PartsINFOID:0000000003533891
FRONT AND REAR AXLE AND SUSPENSION PARTS
Check front and rear axle and suspension parts for excessive play, cracks, wear or other damage.
• Shake each wheel to check for excessive play.
• Rotate each wheel to check for abnormal noise.
• Check the axle and suspension nuts and bolts for looseness.
• Check the strut and shock absorber for oil leakage or other damage.
• Check the suspension ball joints for grease leakage and ball joint dust cover for cracks or other damage.
DRIVE SHAFT
Check the boots and drive shaft for cracks, wear, damage, and
grease leakage.
LGIA0021E
SGIA0506E
SMA525A
SFA901

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ELECTRICAL
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CONTENTS
POWER SUPPLY, GROUND & CIRCUIT ELEMENTS
SERVICE INFORMATION ............................2
PRECAUTIONS ...................................................2
Precaution for Supplemental Restraint System
(SRS) "AIR BAG" and "SEAT BELT PRE-TEN-
SIONER" ...................................................................
2
POWER SUPPLY ROUTING CIRCUIT ...............3
Schematic .................................................................3
Wiring Diagram - POWER - ......................................5
Fuse ........................................................................16
Fusible Link .............................................................16
Circuit Breaker (Built Into BCM) ..............................16
IPDM E/R (INTELLIGENT POWER DISTRI-
BUTION MODULE ENGINE ROOM) .................
17
System Description .................................................17
CAN Communication System Description ...............18
Function of Detecting Ignition Relay Malfunction ....18
CONSULT-II Function (IPDM E/R) ..........................18
Auto Active Test ......................................................20
Terminal and Reference Value for IPDM E/R .........22
IPDM E/R Terminal Arrangement ...........................26
IPDM E/R Power/Ground Circuit Inspection ...........26
Inspection with CONSULT-II (Self-Diagnosis) ........27
Removal and Installation of IPDM E/R ....................28
GROUND CIRCUIT ............................................29
Ground Distribution ..................................................29
HARNESS .........................................................39
Harness Layout .......................................................39
Wiring Diagram Codes (Cell Codes) .......................59
ELECTRICAL UNITS LOCATION ....................63
Electrical Units Location ..........................................63
HARNESS CONNECTOR .................................66
Description ...............................................................66
ELECTRICAL UNITS ........................................68
Terminal Arrangement .............................................68
STANDARDIZED RELAY .................................69
Description ...............................................................69
SUPER MULTIPLE JUNCTION (SMJ) .............71
Terminal Arrangement .............................................71
FUSE BLOCK - JUNCTION BOX (J/B) ............73
Terminal Arrangement .............................................73
FUSE AND FUSIBLE LINK BOX ......................74
Terminal Arrangement .............................................74
FUSE AND RELAY BOX ..................................75
Terminal Arrangement .............................................75

IPDM E/R (INTELLIGENT POWER DISTRIBUTION MODULE ENGINE ROOM)
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IPDM E/R (INTELLIGENT POWER DISTRIBUTION MODULE ENGINE
ROOM)
System DescriptionINFOID:0000000003533835
• IPDM E/R (Intelligent Power Distribution Module Engine Room) integrates the relay box and fuse block
which were originally placed in engine compartment. It controls integrated relays via IPDM E/R control cir-
cuits.
• IPDM E/R-integrated control circuits perform ON-OFF operation of relays, CAN communication control, etc.
• It controls operation of each electrical component via ECM, BCM and CAN communication lines.
CAUTION:
None of the IPDM E/R integrated relays can be removed.
SYSTEMS CONTROLLED BY IPDM E/R
1. Lamp control
Using CAN communication lines, it receives signals from the BCM and controls the following lamps:
• Headlamps (Hi, Lo)
• Parking lamps
• Tail and license lamps
• Front fog lamps
2. Wiper control
Using CAN communication lines, it receives signals from the BCM and controls the front wipers.
3. Rear window defogger relay control
Using CAN communication lines, it receives signals from the BCM and controls the rear window defogger
relay.
4. A/C compressor control
Using CAN communication lines, it receives signals from the ECM and controls the A/C compressor
(magnetic clutch).
5. Starter control
Using CAN communication lines, it receives signals from the BCM and controls the starter relay.
6. Cooling fan control
Using CAN communication lines, it receives signals from the ECM and controls the cooling fan relays.
7. Horn control
Using CAN communication lines, it receives signals from the BCM and controls the horn relay.
CAN COMMUNICATION LINE CONTROL
With CAN communication, by connecting each control unit using two communication lines (CAN L-line, CAN
H-line), it is possible to transmit a maximum amount of information with minimum wiring. Each control unit can
transmit and receive data, and reads necessary information only.
1. Fail-safe control
• When CAN communication with other control units is impossible, IPDM E/R performs fail-safe control.
After CAN communication returns to normal operation, it also returns to normal control.
• Operation of control parts by IPDM E/R during fail-safe mode is as follows:
Controlled system Fail-safe mode
Headlamp• With the ignition switch ON, the headlamp (low) is ON.
• With the ignition switch OFF, the headlamp (low) is OFF.
Tail and parking lamps• With the ignition switch ON, the tail and parking lamps are ON.
• With the ignition switch OFF, the tail and parking lamps are OFF.
Cooling fan• With the ignition switch ON, the cooling fan HI operates.
• With the ignition switch OFF, the cooling fan stops.
Front wiperUntil the ignition switch is turned off, the front wiper LO and HI remains in the same status it
was in just before fail−safe control was initiated.
Rear window defogger Rear window defogger relay OFF
A/C compressor A/C compressor OFF
Front fog lamps Front fog lamp relay OFF

PG-18
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IPDM E/R (INTELLIGENT POWER DISTRIBUTION MODULE ENGINE ROOM)
IPDM E/R STATUS CONTROL
In order to save power, IPDM E/R switches status automatically based on each operating condition.
1. CAN communication status
• CAN communication is normally performed with other control units.
• Individual unit control by IPDM E/R is normally performed.
• When sleep request signal is received from BCM, mode is switched to sleep waiting status.
2. Sleep waiting status
• Process to stop CAN communication is activated.
• All systems controlled by IPDM E/R are stopped. When 1 second has elapsed after CAN communica-
tion with other control units is stopped, mode switches to sleep status.
3. Sleep status
• IPDM E/R operates in low current-consumption mode.
• CAN communication is stopped.
• When a change in CAN communication signal is detected, mode switches to CAN communication sta-
tus.
• When a change in ignition switch signal is detected, mode switches to CAN communication status.
CAN Communication System DescriptionINFOID:0000000003533836
Refer to LAN-4.
Function of Detecting Ignition Relay MalfunctionINFOID:0000000003533837
• When the integrated ignition relay is stuck in a "closed contact" position and cannot be turned OFF, IPDM E/
R turns ON tail and parking lamps for 10 minutes to indicate IPDM E/R malfunction.
• When the state of the integrated ignition relay does not agree with the state of the ignition switch signal
received via CAN communication, the IPDM E/R activates the tail lamp relay.
NOTE:
When the ignition switch is turned ON, the tail lamps are OFF.
CONSULT-II Function (IPDM E/R)INFOID:0000000003533838
CONSULT-II can display each diagnostic item using the diagnostic test modes shown following.
CONSULT-II Start Procedure
Refer to GI-36, "CONSULT-II Start Procedure".
SELF-DIAGNOSTIC RESULTS
Display Item List
Ignition switch signal Ignition relay status Tail lamp relay
ON ON —
OFF OFF —
ON OFF —
OFF ON ON (10 minutes)
IPDM E/R diagnostic Mode Description
SELF-DIAG RESULTS Displays IPDM E/R self-diagnosis results.
DATA MONITOR Displays IPDM E/R input/output data in real time.
CAN DIAG SUPPORT MNTR The result of transmit/receive diagnosis of CAN communication can be read.
ACTIVE TEST Operation of electrical loads can be checked by sending drive signal to them.