2004 INFINITI QX56 Engine Control System

LT-6
HEADLAMP (FOR USA)
Revision: August 20072004 QX56
HEADLAMP (FOR USA)PFP:26010
Component Parts and Harness Connector LocationEKS0079P
System DescriptionEKS0079Q
Control of the headlamp system operation is dependent upon the position of the combination switch (lighting
switch). When the lighting switch is placed in the 2ND position, the BCM (body control module) receives input
requesting the headlamps (and tail lamps) illuminate. This input is communicated to the IPDM E/R (intelligent
power distribution module engine room) across the CAN communication lines. The CPU (central processing
unit) of the IPDM E/R controls the headlamp high and headlamp low relay coils. When energized, these relays
direct power to the respective headlamps, which then illuminate.
OUTLINE
Power is supplied at all times

to headlamp high relay, located in the IPDM E/R, and

to headlamp low relay, located in the IPDM E/R, and

to ignition relay, located in the IPDM E/R, and

through 20A fuse (No. 53, located in the IPDM E/R)

to CPU of the IPDM E/R, and

through 10A fuse [No. 19, located in the fuse block (J/B)]
WKIA3392E

HEADLAMP (FOR CANADA) - DAYTIME LIGHT SYSTEM -
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Revision: August 20072004 QX56
System DescriptionEKS007AB
Daytime light system turns on daytime light lamps while driving. Daytime light lamps are not turned on if
engine is activated with parking brake applied. Release parking brake to turn on daytime light lamps. The
lamps turn off when lighting switch is in the 2ND position or AUTO position (Headlamp is "ON") and when light-
ing switch is in the PASSING position. (Daytime light lamps are not turned off only by parking brake itself.)
A parking brake signal and engine run or stop signal are sent to BCM (body control module) by CAN commu-
nication line.
OUTLINE
Power is supplied at all times

through 10A fuse [No. 19, located in the fuse block (J/B)]

to combination meter terminal 8, and

through 50A fusible link (letter f , located in the fuse and fusible link box)

to BCM terminal 70, and

through 10A fuse [No. 45, located in the IPDM E/R (intelligent power distribution module engine room)]

to daytime light relay terminals 2 and 5.
When the ignition switch is in ON or START position, power is supplied

through 10A fuse [No. 14, located in the fuse block (J/B)]

to combination meter terminal 24, and

through 10A fuse (No. 59, located in the fuse and relay box)

to BCM terminal 38.
Ground is supplied

to combination meter terminal 17 and

to BCM terminal 67

through grounds M57, M61 and M79.
DAYTIME LIGHT OPERATION
With the engine running, the lighting switch in the OFF or 1ST position and parking brake released, the IPDM
E/R receives input requesting the daytime lights illuminate. This input is communicated across the CAN com-
munication lines. The CPU (central processing unit) of the IPDM E/R controls the daytime light relay coil.
When energized, this relay directs power

through daytime light relay terminal 3

to front combination lamp LH terminal 2

through front combination lamp LH terminal 6

through IPDM E/R terminal 55

through 10A fuse (No. 35, located in the IPDM E/R)

through 10A fuse (No. 34, located in the IPDM E/R)

through IPDM E/R terminal 56

to front combination lamp RH terminal 6.
Ground is supplied

to combination lamp RH terminal 2

through grounds E9, E15 and E24.
With power and ground supplied, the daytime lights illuminate. The high beam headlamps are now wired in
series and illuminate at a reduced intensity.
COMBINATION SWITCH READING FUNCTION
Refer to BCS-3, "COMBINATION SWITCH READING FUNCTION" .
AUTO LIGHT OPERATION
For auto light operation, refer to LT-4 8, "System Description" in AUTO LIGHT SYSTEM.
CAN Communication System DescriptionEKS007AC
Refer to LAN-5, "CAN COMMUNICATION" .

HEADLAMP AIMING CONTROL
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Revision: August 20072004 QX56
HEADLAMP AIMING CONTROLPFP:26010
System DescriptionEKS007TL
The headlamp aiming system is controlled by the headlamp aiming switch.
Power is supplied at all times

through 50A fusible link (letter f , located in the fuse and fusible link box)

to BCM (body control module) terminal 70, and

to headlamp low relay, located in the IPDM E/R (intelligent power distribution module engine room).
With the ignition switch in the ON or START position, power is supplied

through 10A fuse (No. 59, located in the fuse and relay box)

to BCM terminal 38.
When the lighting switch is in the 2ND position or AUTO position (auto lights ON), the headlamp low relay
(located in the IPDM E/R) is energized. When energized, power is supplied

through 15A fuse (No. 41, located in the IPDM E/R)

through terminal 26 of the IPDM E/R

to terminal 8 of each front combination lamp (headlamp aiming motor).
Ground is supplied

to terminal 4 of each front combination lamp (headlamp aiming motor)

through grounds E9, E15 and E24, and

to terminal 7 of each front combination lamp (headlamp aiming motor)

through headlamp aiming switch and grounds M57, M61 and M79.
With power and ground supplied, headlamp aiming motors operate according to the aiming switch position.

FRONT FOG LAMP
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Revision: August 20072004 QX56
FRONT FOG LAMPPFP:26150
Component Parts and Harness Connector LocationEKS007B4
System DescriptionEKS007B5
Control of the fog lamps is dependent upon the position of the combination switch (lighting switch). The light-
ing switch must be in the 2ND position or AUTO position (LOW beam is ON) for front fog lamp operation.
When the lighting switch is placed in the fog lamp position, the BCM (body control module) receives input sig-
nal requesting the fog lamps to illuminate. When the headlamps are illuminated, this input signal is communi-
cated to the IPDM E/R (intelligent power distribution module engine room) across the CAN communication
lines. The CPU (central processing unit) of the IPDM E/R controls the front fog lamp relay coil. When acti-
vated, this relay directs power to the front fog lamps.
OUTLINE
Power is supplied at all times

to ignition relay, located in the IPDM E/R, and

to front fog lamp relay, located in the IPDM E/R, and

through 20A fuse (No. 53, located in the IPDM E/R)

to CPU of the IPDM E/R, and

through 50A fusible link (letter f , located in the fuse and fusible link box)

to BCM terminal 70.
When the ignition switch is in ON or START position, power is supplied

to ignition relay, located in the IPDM E/R, and

through 10A fuse (No. 59, located in the fuse and relay box)

to BCM terminal 38.
Ground is supplied

to BCM terminal 67

through grounds M57, M61 and M79, and

to IPDM E/R terminals 38 and 59
WKIA3395E

LT-108
PARKING, LICENSE PLATE AND TAIL LAMPS
Revision: August 20072004 QX56
PARKING, LICENSE PLATE AND TAIL LAMPSPFP:26550
Component Parts and Harness Connector LocationEKS007CD
System DescriptionEKS007CE
Control of the parking, license plate, and tail lamp operation is dependent upon the position of the lighting
switch (combination switch). When the lighting switch is placed in the 1ST position, the BCM (body control
module) receives input signal requesting the parking, license plate, side marker and tail lamps to illuminate.
This input signal is communicated to the IPDM E/R (intelligent power distribution module engine room) across
the CAN communication lines. The CPU (central processing unit) of the IPDM E/R controls the tail lamp relay
coil. This relay, when energized, directs power to the parking, license plate and tail lamps, which then illumi-
nate.
Power is supplied at all times

to tail lamp relay, located in the IPDM E/R, and

through 20A fuse (No. 53, located in the IPDM E/R)

to CPU of the IPDM E/R, and

to ignition relay, located in the IPDM E/R, and

through 50A fusible link (letter f , located in the fuse and fusible link box)

to BCM terminal 70.
With the ignition switch in the ON or START position, power is supplied

through 10A fuse (No. 59, located in the fuse and relay box)

to BCM terminal 38, and

to ignition relay, located in the IPDM E/R.
Ground is supplied

to BCM terminal 67

through grounds M57, M61 and M79, and

to IPDM E/R terminals 38 and 59

through grounds E9, E15 and E24.
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TRAILER TOW
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Revision: August 20072004 QX56
TRAILER TOWPFP:93020
Component Parts and Harness Connector LocationEKS007CT
System DescriptionEKS007CU
Power is supplied at all times

through 50A fusible link (letter f , located in the fuse and fusible link box)

to BCM (body control module) terminal 70, and

through 10A fuse [No. 32, located in the IPDM E/R (intelligent power distribution module engine room)]

through IPDM E/R terminal 61

to trailer tow relay 1 terminal 3, and

through 20A fuse (No. 53, located in the IPDM E/R)

to CPU of the IPDM E/R, and

through 30A fusible link (letter j , located in the fuse and fusible link box)

to trailer tow relay 2 terminals 3 and 6, and

through 40A fusible link (letter k , located in the fuse and fusible link box)

to electric brake (pre-wiring) terminal 5.
With the ignition switch in the ON or START position, power is supplied
WKIA3398E

LT-152
ILLUMINATION
Revision: August 20072004 QX56
ILLUMINATIONPFP:27545
Component Parts and Harness Connector LocationEKS007D9
System DescriptionEKS007DA
Control of the illumination lamps operation is dependent upon the position of the lighting switch (combination
switch). When the lighting switch is placed in the 1ST or 2ND position (or if the auto light system is activated)
the BCM (body control module) receives input signal requesting the illumination lamps to illuminate. This input
signal is communicated to the IPDM E/R (intelligent power distribution module engine room) across the CAN
communication lines. The CPU (central processing unit) of the IPDM E/R controls the tail lamp relay coil. This
relay, when energized, directs power to the illumination lamps, which then illuminate.
Power is supplied at all times

to tail lamp relay, located in the IPDM E/R, and

through 50A fusible link (letter f , located in the fuse and fusible link box)

to BCM terminal 70, and

through 20A fuse (No. 53, located in the IPDM E/R)

to CPU of the IPDM E/R, and

through 10A fuse [No.19, located in fuse block (J/B)]

to combination meter terminal 8, and
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MA-1
MAINTENANCE
L MAINTENANCE
CONTENTS
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Revision: August 20072004 QX56 PRECAUTIONS .......................................................... 2
Precautions for Supplemental Restraint System
(SRS) “AIR BAG” and “SEAT BELT PRE-TEN-
SIONER” .................................................................. 2
PREPARATION ........................................................... 3
Special Service Tools ............................................... 3
GENERAL MAINTENANCE ....................................... 4
General Maintenance ............................................... 4
PERIODIC MAINTENANCE ....................................... 6
Introduction of Periodic Maintenance ....................... 6
Maintenance For Off-road Driving (4WD only) ......... 6
Schedule 1 ............................................................... 6
EMISSION CONTROL SYSTEM MAINTE-
NANCE .................................................................. 6
CHASSIS AND BODY MAINTENANCE ............... 7
Schedule 2 ............................................................... 8
EMISSION CONTROL SYSTEM MAINTE-
NANCE .................................................................. 8
CHASSIS AND BODY MAINTENANCE ............... 9
RECOMMENDED FLUIDS AND LUBRICANTS ...... 10
Fluids and Lubricants ............................................. 10
SAE Viscosity Number ............................................11
GASOLINE ENGINE OIL .....................................11
ANTI-FREEZE COOLANT MIXTURE RATIO ......11
ENGINE MAINTENANCE ......................................... 12
Checking Drive Belts .............................................. 12
DRIVE BELT TENSION ...................................... 12
Changing Engine Coolant ...................................... 12
DRAINING ENGINE COOLANT ......................... 12
REFILLING ENGINE COOLANT ........................ 13
FLUSHING COOLING SYSTEM ......................... 14
Checking Fuel Lines ............................................... 15
Changing Fuel Filter ............................................... 15
Changing Engine Air Cleaner Filter ........................ 15
VISCOUS PAPER TYPE ..................................... 15
Changing Engine Oil .............................................. 16
Changing Oil Filter ................................................. 16
Changing Spark Plugs ........................................... 17
REMOVAL ........................................................... 17INSPECTION AFTER REMOVAL ....................... 18
INSTALLATION ................................................... 19
Checking EVAP Vapor Lines .................................. 19
CHASSIS AND BODY MAINTENANCE ................... 20
Changing In-cabin Microfilter .................................. 20
Checking Exhaust System ...................................... 21
Checking A/T Fluid ................................................. 21
Changing A/T Fluid ................................................. 23
Checking Transfer Fluid ......................................... 24
FLUID LEAKAGE AND FLUID LEVEL ................ 24
Changing Transfer Fluid ......................................... 24
DRAINING ........................................................... 24
FILLING ............................................................... 24
Checking Propeller Shaft ........................................ 24
Checking Final Drive Oil ......................................... 24
Changing Final Drive Oil ......................................... 25
Balancing Wheels ................................................... 25
REMOVAL ........................................................... 25
WHEEL BALANCE ADJUSTMENT ..................... 25
Tire Rotation ........................................................... 27
Checking Brake Fluid Level and Leaks .................. 27
Checking Brake Lines and Cables ......................... 27
Checking Disc Brake .............................................. 28
ROTOR ................................................................ 28
CALIPER ............................................................. 28
PAD ..................................................................... 28
Checking Steering Gear and Linkage ..................... 28
STEERING GEAR ............................................... 28
STEERING LINKAGE ......................................... 28
Checking Power Steering Fluid and Lines .............. 29
CHECKING FLUID LEVEL .................................. 29
CHECKING LINES .............................................. 29
Checking Axle and Suspension Parts .................... 29
FRONT AND REAR AXLE AND SUSPENSION
PARTS ................................................................. 29
DRIVE SHAFT ..................................................... 29
Lubricating Locks, Hinges and Hood Latches ........ 30
Checking Seat Belts, Buckles, Retractors, Anchors
and Adjusters .......................................................... 31