2004 INFINITI QX56 Meter

EC-628Revision: August 2007
ASCD INDICATOR
2004 QX56
ASCD INDICATORPFP:24814
Component DescriptionUBS00HDT
ASCD indicator lamp illuminates to indicate ASCD operation status. Lamp has two indicators, CRUISE and
SET, and is integrated in combination meter.
CRUISE indicator illuminates when ON/OFF switch on ASCD steering switch is turned ON to indicated that
ASCD system is ready for operation.
SET indicator illuminates when following conditions are met.

CRUISE indicator is illuminated.

SET switch on ASCD steering switch is turned ON while vehicle speed is within the range of ASCD set-
ting.
SET indicator remains lit during ASCD control.
Refer to EC-647, "
AUTOMATIC SPEED CONTROL DEVICE (ASCD)" for the ASCD function.
CONSULT-II Reference Value in Data Monitor ModeUBS00HDU
Specification data are reference value.
MONITOR ITEM CONDITION SPECIFICATION
CRUISE LAMP

Ignition switch: ON
ON/OFF(MAIN) switch: Pressed
at the 1st time → at the 2nd timeON → OFF
SET LAMP

ON/OFF switch: ON

When vehicle speed is
between 40 km/h (25 MPH)
and 144 km/h (89 MPH)

COAST/SET switch: Pressed ON

COAST/SET switch: Released OFF

EC-630Revision: August 2007
ASCD INDICATOR
2004 QX56
Diagnostic ProcedureUBS00HDW
1. CHECK OVERALL FUNCTION
Check ASCD indicator under the following conditions.
OK or NG
OK >>INSPECTION END
NG >> GO TO 2.
2. CHECK DTC
Check that DTC U1000 or U1001 is not displayed.
OK or NG
OK >> GO TO 3.
NG >> Perform trouble diagnosis for DTC U1000, U1001. Refer to EC-135, "
DTC U1000, U1001 CAN
COMMUNICATION LINE" .
3. CHECK DTC WITH COMBINATION METER
Refer to DI-5, "
COMBINATION METERS" .
OK or NG
OK >> GO TO 4.
NG >> Go to DI-5, "
COMBINATION METERS" .
4. CHECK INTERMITTENT INCIDENT
Refer to EC-127, "
TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT" .
>>INSPECTION END
ASCD INDICATOR CONDITION SPECIFICATION
CRUISE LAMP

Ignition switch: ON
ON/OFF(MAIN) switch: Pressed at
the 1st time → at the 2nd timeON → OFF
SET LAMP

ON/OFF(MAIN) switch: ON

When vehicle speed is between
40 km/h (25 MPH) and 144 km/h
(89 MPH)

COAST/SET switch: Pressed ON

COAST/SET switch: Released OFF

AUTOMATIC SPEED CONTROL DEVICE (ASCD)
EC-647
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Revision: August 20072004 QX56
AUTOMATIC SPEED CONTROL DEVICE (ASCD)PFP:18930
System DescriptionUBS00HE7
INPUT/OUTPUT SIGNAL CHART
*: This signal is sent to the ECM through CAN communication line.
BASIC ASCD SYSTEM
Refer to Owner's Manual for ASCD operating instructions.
Automatic Speed Control Device (ASCD) allows a driver to keep vehicle at predetermined constant speed
without pressing accelerator pedal. Driver can set vehicle speed in advance between approximately 40 km/h
(25 MPH) and 144 km/h (89 MPH).
ECM controls throttle angle of electric throttle control actuator to regulate engine speed.
Operation status of ASCD is indicated by CRUISE indicator and SET indicator in combination meter. If any
malfunction occurs in ASCD system, it automatically deactivates control.
SET OPERATION
Press ON/OFF(MAIN) switch. (The CRUISE indicator in combination meter illuminates.)
When vehicle speed reaches a desired speed between approximately 40 km/h (25 MPH) and 144 km/h (89
MPH), press COAST/SET switch. (Then SET indicator in combination meter illuminates.)
ACCEL OPERATION
If the ACCEL/RESUME switch is pressed during cruise control driving, increase the vehicle speed until the
switch is released or vehicle speed reaches maximum speed controlled by the system.
And then ASCD will keep the new set speed.
CANCEL OPERATION
When any of following conditions exist, cruise operation will be canceled.

CANCEL switch is pressed

More than 2 switches at ASCD steering switch are pressed at the same time (Set speed will be cleared)

Brake pedal is depressed

Selector lever is changed to N, P, R position

Vehicle speed decreased to 13 km/h (8 MPH) lower than the set speed

VDC/TCS system is operated
When the ECM detects any of the following conditions, the ECM will cancel the cruise operation and inform
the driver by blinking indicator lamp.

Engine coolant temperature is slightly higher than the normal operating temperature, CRUISE lamp may
blink slowly.
When the engine coolant temperature decreases to the normal operating temperature, CRUISE lamp will
stop blinking and the cruise operation will be able to work by pressing COAST/SET switch or ACCEL/
RESUME switch.

Malfunction for some self-diagnoses regarding ASCD control: SET lamp will blink quickly.
If ON/OFF(MAIN) switch is turned to OFF during ASCD is activated, all of ASCD operations will be canceled
and vehicle speed memory will be erased.
COAST OPERATION
When the COAST/SET switch is pressed during cruise control driving, decrease vehicle set speed until the
switch is released. And then ASCD will keep the new set speed.
Sensor Input signal to ECM ECM function Actuator
ASCD brake switch Brake pedal operation
ASCD vehicle speed controlElectric throttle control
actuator Stop lamp switch Brake pedal operation
ASCD steering switch ASCD steering switch operation
Park/Neutral position (PNP)
switchGear position
Combination meter* Vehicle speed
TCM* Powertrain revolution

SQUEAK AND RATTLE TROUBLE DIAGNOSIS
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Revision: August 20072004 QX56
73982-9E000: 45 mm (1.77 in) thick, 50 x 50 mm (1.97 x 1.97 in)/73982-50Y00: 10 mm (0.39 in) thick, 50 x 50
mm (1.97 x 1.97 in)
INSULATOR (Light foam block)
80845-71L00: 30 mm (1.18 in) thick, 30 x 50 mm (1.18 x 1.97 in)
FELT CLOTH TAPE
Used to insulate where movement does not occur. Ideal for instrument panel applications.
68370-4B000: 15 x 25 mm (0.59 x 0.98 in) pad/68239-13E00: 5 mm (0.20 in) wide tape roll
The following materials, not found in the kit, can also be used to repair squeaks and rattles.
UHMW (TEFLON) TAPE
Insulates where slight movement is present. Ideal for instrument panel applications.
SILICONE GREASE
Used in place of UHMW tape that will be visible or not fit.
Note: Will only last a few months.
SILICONE SPRAY
Use when grease cannot be applied.
DUCT TAPE
Use to eliminate movement.
CONFIRM THE REPAIR
Confirm that the cause of a noise is repaired by test driving the vehicle. Operate the vehicle under the same
conditions as when the noise originally occurred. Refer to the notes on the Diagnostic Worksheet.
Generic Squeak and Rattle TroubleshootingEIS0063B
Refer to Table of Contents for specific component removal and installation information.
INSTRUMENT PANEL
Most incidents are caused by contact and movement between:
1. The cluster lid A and instrument panel
2. Acrylic lens and combination meter housing
3. Instrument panel to front pillar garnish
4. Instrument panel to windshield
5. Instrument panel mounting pins
6. Wiring harnesses behind the combination meter
7. A/C defroster duct and duct joint
These incidents can usually be located by tapping or moving the components to duplicate the noise or by
pressing on the components while driving to stop the noise. Most of these incidents can be repaired by apply-
ing felt cloth tape or silicone spray (in hard to reach areas). Urethane pads can be used to insulate wiring har-
ness.
CAUTION:
Do not use silicone spray to isolate a squeak or rattle. If you saturate the area with silicone, you will
not be able to recheck the repair.
CENTER CONSOLE
Components to pay attention to include:
1. Shifter assembly cover to finisher
2. A/C control unit and cluster lid C
3. Wiring harnesses behind audio and A/C control unit
The instrument panel repair and isolation procedures also apply to the center console.
DOORS
Pay attention to the:
1. Finisher and inner panel making a slapping noise
2. Inside handle escutcheon to door finisher
3. Wiring harnesses tapping
4. Door striker out of alignment causing a popping noise on starts and stops

EM-2Revision: August 20072004 QX56 CAMSHAFT ............................................................... 43
Removal and Installation ........................................ 43
REMOVAL ........................................................... 43
INSPECTION AFTER REMOVAL ........................ 47
INSTALLATION .................................................... 49
Valve Clearance ...................................................... 52
INSPECTION ....................................................... 52
ADJUSTMENT .................................................... 54
OIL SEAL .................................................................. 56
Removal and Installation of Valve Oil Seal ............. 56
REMOVAL ........................................................... 56
INSTALLATION .................................................... 56
Removal and Installation of Front Oil Seal ............. 57
REMOVAL ........................................................... 57
INSTALLATION .................................................... 57
Removal and Installation of Rear Oil Seal .............. 57
REMOVAL ........................................................... 57
INSTALLATION .................................................... 58
CYLINDER HEAD ..................................................... 59
On-Vehicle Service ................................................. 59
CHECKING COMPRESSION PRESSURE ......... 59
Removal and Installation ........................................ 60
REMOVAL ........................................................... 60
INSPECTION AFTER REMOVAL ........................ 61
INSTALLATION .................................................... 61
Disassembly and Assembly .................................... 62
DISASSEMBLY ................................................... 62
ASSEMBLY ......................................................... 63
Inspection After Disassembly ................................. 64
CYLINDER HEAD DISTORTION ........................ 64
VALVE DIMENSIONS .......................................... 65
VALVE GUIDE CLEARANCE .............................. 66
VALVE GUIDE REPLACEMENT ......................... 66
VALVE SEAT CONTACT ..................................... 68
VALVE SEAT REPLACEMENT ........................... 68
VALVE SPRING SQUARENESS ......................... 69
VALVE SPRING DIMENSIONS AND VALVE
SPRING PRESSURE LOAD ............................... 69
ENGINE ASSEMBLY ................................................ 70
Removal and Installation ........................................ 70
REMOVAL ........................................................... 70
INSTALLATION .................................................... 71
INSPECTION AFTER INSTALLATION ................ 72
CYLINDER BLOCK ................................................... 73
Disassembly and Assembly .................................... 73
DISASSEMBLY ................................................... 74ASSEMBLY ..........................................................77
How to Select Piston and Bearing ..........................82
DESCRIPTION ....................................................82
HOW TO SELECT PISTON .................................83
HOW TO SELECT CONNECTING ROD BEAR-
ING .......................................................................84
HOW TO SELECT MAIN BEARING ....................85
Inspection After Disassembly ..................................89
CRANKSHAFT END PLAY ..................................89
CONNECTING ROD SIDE CLEARANCE ...........89
PISTON AND PISTON PIN CLEARANCE ...........89
PISTON RING SIDE CLEARANCE .....................90
PISTON RING END GAP ....................................90
CONNECTING ROD BEND AND TORSION .......91
CONNECTING ROD BEARING (BIG END) ........91
CONNECTING ROD BUSHING OIL CLEAR-
ANCE (SMALL END) ...........................................91
CYLINDER BLOCK DISTORTION ......................92
MAIN BEARING HOUSING INSIDE DIAMETER ...93
PISTON TO CYLINDER BORE CLEARANCE ....93
CRANKSHAFT JOURNAL DIAMETER ...............94
CRANKSHAFT PIN DIAMETER ..........................95
OUT-OF-ROUND AND TAPER OF CRANK-
SHAFT .................................................................95
CRANKSHAFT RUNOUT ....................................95
CONNECTING ROD BEARING OIL CLEAR-
ANCE ...................................................................95
MAIN BEARING OIL CLEARANCE .....................96
CRUSH HEIGHT OF MAIN BEARING ................97
CRUSH HEIGHT OF CONNECTING ROD
BEARING .............................................................97
MAIN BEARING CAP BOLT DIAMETER .............97
CONNECTING ROD BOLT DIAMETER ..............98
SERVICE DATA AND SPECIFICATIONS (SDS) ......99
Standard and Limit ..................................................99
GENERAL SPECIFICATIONS .............................99
DRIVE BELTS ......................................................99
EXHAUST MANIFOLD ........................................99
CAMSHAFT AND CAMSHAFT BEARING ......... 100
CYLINDER HEAD .............................................. 102
CYLINDER BLOCK ............................................ 104
PISTON, PISTON RING AND PISTON PIN ...... 105
CONNECTING ROD .......................................... 105
CRANKSHAFT ................................................... 106
MAIN BEARING ................................................. 107

EM-38Revision: August 2007
TIMING CHAIN
2004 QX56
10. Remove the oil pump drive spacer.

Hold and remove the flat space of the oil pump drive spacer
by pulling it forward.
11. Remove the oil pump. Refer to LU-13, "
Removal and Installation" .
12. Remove the chain tensioner on the left bank using the following steps.
NOTE:
To remove the timing chain and associated parts, start with those on the left bank. The procedure for
removing parts on the right bank is omitted because it is the same as that for the left bank.
a. Squeeze the return-proof clip ends using suitable tool and push
the plunger into the tensioner body.
b. Secure the plunger using stopper pin.

Stopper pin is made from hard wire approximately 1 mm (0.04
in) in diameter.
c. Remove the bolts and chain tensioner.
WAR NIN G:
Plunger, spring, and spring seat pop out when (squeezing)
return-proof clip without holding plunger head. It may
cause serious injuries. Always hold plunger head when
removing.
NOTE:

Stop the plunger in the fully extended position by using the
return-proof clip 1 if the stopper pin is removed.

Push the plunger 2 into the tensioner body while squeezing
the return-proof clip 1. Secure it using stopper pin 3.
13. Remove the chain tension guide and slack guide.
14. Remove the timing chain and crankshaft sprocket.
15. Loosen the camshaft sprocket bolts as shown and remove the
camshaft sprocket.
CAUTION:
To avoid interference between valves and pistons, do not
turn crankshaft or camshaft when timing chain is discon-
nected.
16. Repeat the same procedure to remove the right timing chain and
associated parts.
KBIA2512E
KBIA2479E
KBIA2483E
KBIA2513E

EM-40Revision: August 2007
TIMING CHAIN
2004 QX56
2. Install camshaft sprockets.

Install intake and exhaust camshaft sprocket by selectively
using the groove of dowel pin according to the bank (common
part used for both banks).

Lock the hexagonal part of camshaft in the same way as for
removal, and tighten bolts.
3. Install crankshaft sprockets for both banks.

Install each crankshaft sprocket so that its flange side (the
larger diameter side without teeth) faces in the direction as
shown.
NOTE:
The same parts are used but facing directions are different.
4. Install timing chains and associated parts.

Align the mating mark on each sprocket and the timing chain for installation.
CAUTION:

Before installing chain tensioner, it is possible to change the position of mating mark on tim-
ing chain and each sprocket. After the mating marks are aligned, keep them aligned by hold-
ing them by hand.

Install slack guides and tension guides onto correct side by checking with identification mark on sur-
face.

Install chain tensioner with plunger locked in with stopper pin.
CAUTION:

Before and after the installation of chain tensioner, make sure that the mating mark on timing
chain is not out of alignment.

After installing chain tensioner, remove the stopper pin to release tensioner. Make sure ten-
sioner is released.

To avoid chain-link skipping of timing chain, never move crankshaft or camshafts until front
cover is installed.
5. In the same way as for right bank, install the timing chain and associated parts on the left side.
6. Install the oil pump.
7. Install the oil pump drive spacer as follows:

Install so that the front mark on the front edge of oil pump
drive spacer faces the front of the engine.

Insert oil pump drive spacer according to the directions of the
crankshaft key and the two flat surfaces of oil pump inner
rotor.

If the positional relationship does not allow the insertion,
rotate oil pump inner rotor to allow the oil pump drive spacer
to be inserted.
KBIA2480E
KBIA2515E
KBIA2490E

EM-44Revision: August 2007
CAMSHAFT
2004 QX56
b. At this time, make sure both intake and exhaust cam lobes of
No. 1 cylinder (top front on left bank) point outside.

If they do not point outside, turn crankshaft pulley once more.
3. Remove the chain case cover (right bank) and (left bank).
a. Loosen and remove the bolts in the reverse order shown.
b. Cut the liquid gasket to remove covers using Tool.
CAUTION:
Do not damage mating surfaces.
4. Paint matching marks on the timing chain links aligning with
camshaft sprocket matching marks.
5. Remove the chain tensioner on the left bank using the following steps.
WAR NIN G:
Plunger, spring, and spring seat pop out when squeezing return-proof clip without holding
plunger head. It may cause serious injuries. Always hold plunger head when removing.
a. Squeeze return-proof clip ends using suitable tool and push the
plunger into the tensioner body.
b. Secure plunger using stopper pin.

Stopper pin is made from hard wire approximately 1 mm (0.04
in) in diameter.
c. Remove the bolts and the chain tensioner.
KBIA0400J
Tool number: KV10111100 (J-37228)
KBIA2475E
KBIA2488E
KBIA2479E