transmission INFINITI QX4 2005 Factory Service Manual

EC-146Revision: October 2005
TROUBLE DIAGNOSIS - SPECIFICATION VALUE
2005 QX56
TROUBLE DIAGNOSIS - SPECIFICATION VALUEPFP:00031
DescriptionUBS00L0F
The specification (SP) value indicates the tolerance of the value that is displayed in “DATA MONITOR (SPEC)”
mode of CONSULT-II during normal operation of the Engine Control System. When the value in “DATA MONI-
TOR (SPEC)” mode is within the SP value, the Engine Control System is confirmed OK. When the value in
“DATA MONITOR (SPEC)” mode is NOT within the SP value, the Engine Control System may have one or
more malfunctions.
The SP value is used to detect malfunctions that may affect the Engine Control System, but will not light the
MIL.
The SP value will be displayed for the following three items:

B/FUEL SCHDL (The fuel injection pulse width programmed into ECM prior to any learned on board cor-
rection)

A/F ALPHA-B1/B2 (The mean value of air-fuel ratio feedback correction factor per cycle)

MAS A/F SE-B1 (The signal voltage of the mass air flow sensor)
Testing ConditionUBS00L0G

Vehicle driven distance: More than 5,000 km (3,017 miles)

Barometric pressure: 98.3 - 104.3 kPa (1.003 - 1.064 kg/cm2 , 14.25 - 15.12 psi)

Atmospheric temperature: 20 - 30°C (68 - 86°F)

Engine coolant temperature: 75 - 95°C (167 - 203°F)

Transmission: Warmed-up*1

Electrical load: Not applied*2

Engine speed: Idle
*1: After the engine is warmed up to normal operating temperature, drive vehicle until “ATF TEMP SE 1” (A/T
fluid temperature sensor signal) indicates more than 60°C (140°F).
*2: Rear window defogger switch, air conditioner switch, lighting switch are OFF. Steering wheel is straight
ahead.
Inspection ProcedureUBS00L0H
NOTE:
Perform “DATA MONITOR (SPEC)” mode in maximum scale display.
1. Perform EC-72, "
Basic Inspection" .
2. Confirm that the testing conditions indicated above are met.
3. Select “B/FUEL SCHDL”, “A/F ALPHA-B1”, “A/F ALPHA-B2”
and “MAS A/F SE-B1” in “DATA MONITOR (SPEC)” mode with
CONSULT-II.
4. Make sure that monitor items are within the SP value.
5. If NG, go to EC-147, "
Diagnostic Procedure" .
SEF 6 01 Z

EC-152Revision: October 2005
TROUBLE DIAGNOSIS - SPECIFICATION VALUE
2005 QX56
15. DISCONNECT AND RECONNECT ECM HARNESS CONNECTOR
1. Stop the engine.
2. Disconnect ECM harness connector. Check pin terminal and connector for damage, and then reconnect it.
>> GO TO 16.
16. CHECK “A/F ALPHA-B1”, “A/F ALPHA-B2”
1. Start engine.
2. Select “A/F ALPHA-B1”, “A/F ALPHA-B2” in “DATA MONITOR (SPEC)” mode, and make sure that the
each indication is within the SP value.
OK or NG
OK >>INSPECTION END
NG >> Detect malfunctioning part according to EC-104, "
Symptom Matrix Chart" .
17. CHECK “B/FUEL SCHDL”
Select “B/FUEL SCHDL” in “DATA MONITOR (SPEC)” mode, and
make sure that the indication is within the SP value.
OK or NG
OK >>INSPECTION END
NG (More than the SP value)>>GO TO 18.
NG (Less than the SP value)>>GO TO 25.
18. DETECT MALFUNCTIONING PART
1. Check for the cause of large engine friction. Refer to the following.
–Engine oil level is too high
–Engine oil viscosity
–Belt tension of power steering, alternator, A/C compressor, etc. is excessive
–Noise from engine
–Noise from transmission, etc.
2. Check for the cause of insufficient combustion. Refer to the following.
–Valve clearance malfunction
–Intake valve timing control function malfunction
–Camshaft sprocket installation malfunction, etc.
>> Repair or replace malfunctioning part, and then GO TO 30.
19. CHECK INTAKE SYSTEM
Check for the cause of uneven air flow through mass air flow sensor. Refer to the following.

Crushed air ducts

Malfunctioning seal of air cleaner element

Uneven dirt of air cleaner element

Improper specification of intake air system
OK or NG
OK >> GO TO 21.
NG >> Repair or replace malfunctioning part, and then GO TO 20.
PBIB2332E

DTC U1000, U1001 CAN COMMUNICATION LINE
EC-163
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Revision: October 20052005 QX56
DTC U1000, U1001 CAN COMMUNICATION LINEPFP:23710
DescriptionUBS00H0I
CAN (Controller Area Network) is a serial communication line for real time application. It is an on-vehicle mul-
tiplex communication line with high data communication speed and excellent error detection ability. Many elec-
tronic control units are equipped onto a vehicle, and each control unit shares information and links with other
control units during operation (not independent). In CAN communication, control units are connected with 2
communication lines (CAN H line, CAN L line) allowing a high rate of information transmission with less wiring.
Each control unit transmits/receives data but selectively reads required data only.
On Board Diagnosis LogicUBS00H0J
*1: This self-diagnosis has the one trip detection logic.
*2: The MIL will not light up for this diagnosis.
DTC Confirmation ProcedureUBS00H0K
1. Turn ignition switch ON and wait at least 3 seconds.
2. Select “DATA MONITOR” mode with CONSULT-II.
3. If 1st trip DTC is detected, go to EC-165, "
Diagnostic Procedure" .
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
U1000*
1
1000*1
CAN communication line

ECM cannot communicate to other control
units.

ECM cannot communicate for more than the
specified time.

Harness or connectors
(CAN communication line is open or
shorted) U1001*
2
1001*2

EC-290Revision: October 2005
DTC P0335 CKP SENSOR (POS)
2005 QX56
Component InspectionUBS00H46
CRANKSHAFT POSITION SENSOR (POS)
1. Loosen the fixing bolt of the sensor.
2. Disconnect crankshaft position sensor (POS) harness connector.
3. Remove the sensor.
4. Visually check the sensor for chipping.
5. Check resistance as shown in the figure.
Removal and InstallationUBS00H47
CRANKSHAFT POSITION SENSOR (POS)
Refer to AT-244, "TRANSMISSION ASSEMBLY" .
PBIB0563E
Terminal No. (Polarity) Resistance Ω [at 25°C (77°F)]
1 (+) - 2 (-)
Except 0 or ∞ 1 (+) - 3 (-)
2 (+) - 3 (-)
PBIB0564E

DTC P1574 ICC VEHICLE SPEED SENSOR
EC-577
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Revision: October 20052005 QX56
DTC P1574 ICC VEHICLE SPEED SENSORPFP:31036
Component DescriptionUBS00HZ6
The ECM receives two vehicle speed signals via CAN communication line. One is sent from “unified meter and
A/C amp.”, and the other is from TCM (Transmission control module). The ECM uses these signals for ICC
control. Refer to ACS-6, "
DESCRIPTION" for ICC functions.
On Board Diagnosis LogicUBS00HZ7

This self-diagnosis has the one trip detection logic.

The MIL will not light up for this self-diagnosis.
NOTE:

If DTC P1574 is displayed with DTC U1000, U1001, first perform the trouble diagnosis for DTC
U1000, U1001. Refer to EC-163, "
DTC U1000, U1001 CAN COMMUNICATION LINE" .

If DTC P1574 is displayed with DTC P0500, first perform the trouble diagnosis for DTC P0500.
Refer to EC-372, "
DTC P0500 VSS" .

If DTC P1574 is displayed with DTC P0605, first perform the trouble diagnosis for DTC P0605.
Refer to EC-383, "
DTC P0605 ECM" .
DTC Confirmation ProcedureUBS00HZ8
CAUTION:
Always drive vehicle at a safe speed.
NOTE:
If DTC Confirmation Procedure has been previously conducted, always turn ignition switch OFF and wait at
least 10 seconds before conducting the next test.
TESTING CONDITION:
Step 3 may be conducted with the drive wheels lifted in the shop or by driving the vehicle. If a road test
is expected to be easier, it is unnecessary to lift the vehicle.
WITH CONSULT-II
1. Start engine.
2. Select “DATA MONITOR” mode with CONSULT-II.
3. Drive the vehicle at more than 40 km/h (25MPH).
4. If DTC is detected, go to EC-578, "
Diagnostic Procedure" .
WITH GST
Follow the procedure “WITH CONSULT-II” above.
DTC No. Trouble Diagnosis Name DTC Detecting Condition Possible Cause
P1574
1574ICC vehicle speed sensorECM detects a difference between two vehicle
speed signals is out of the specified range.

Harness or connectors
(The CAN communication line is open or
shorted.)

Combination meter

ABS actuator and electric unit (control unit)

Wheel sensor

TCM

ECM
SEF 0 58 Y

DTC P1574 ASCD VEHICLE SPEED SENSOR
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Revision: October 20052005 QX56
DTC P1574 ASCD VEHICLE SPEED SENSORPFP:31036
Component DescriptionUBS00HBM
The ECM receives two vehicle speed sensor signals via CAN communication line. One is sent from combina-
tion meter and the other is from TCM (Transmission control module). The ECM uses these signals for ASCD
control. Refer to EC-29, "
AUTOMATIC SPEED CONTROL DEVICE (ASCD)" for ASCD functions.
On Board Diagnosis LogicUBS00HBN
This self-diagnosis has the one trip detection logic.
The MIL will not light up for this diagnosis.
NOTE:

If DTC P1574 is displayed with DTC U1000, U1001, first perform the trouble diagnosis for DTC
U1000, U1001. Refer to EC-163, "
DTC U1000, U1001 CAN COMMUNICATION LINE" .

If DTC P1574 is displayed with DTC P0500, first perform the trouble diagnosis for DTC P0500.
Refer to EC-372, "
DTC P0500 VSS".

If DTC P1574 is displayed with DTC P0605, first perform the trouble diagnosis for DTC P0605.
Refer to EC-383, "
DTC P0605 ECM".
DTC Confirmation ProcedureUBS00HBO
CAUTION:
Always drive vehicle at a safe speed.
NOTE:
If DTC Confirmation Procedure has been previously conducted, always turn ignition switch OFF and wait at
least 10 seconds before conducting the next test.
TESTING CONDITION:
Step 3 may be conducted with the drive wheels lifted in the shop or by driving the vehicle. If a road test
is expected to be easier, it is unnecessary to lift the vehicle.
WITH CONSULT-II
1. Start engine (VDC switch OFF).
2. Select “DATA MONITOR” mode with CONSULT-II.
3. Drive the vehicle at more than 40 km/h (25 MPH).
4. If DTC is detected, go to EC-580, "
Diagnostic Procedure" .
WITH GST
Follow the procedure “WITH CONSULT-II” above.
DTC No.Trouble Diagnosis
NameDTC Detecting Condition Possible Cause
P1574
1574ASCD vehicle speed
sensorECM detects a difference between two vehicle
speed signals is out of the specified range.

Harness or connectors
(The CAN communication line is open or
shorted.)

Combination meter

ABS actuator and electric unit (control unit)

Wheel sensor

TCM

ECM
SEF 0 58 Y

EM-56Revision: October 2005
OIL SEAL
2005 QX56
Removal and Installation of Front Oil SealEBS00LMC
REMOVAL
1. Remove the radiator. Refer to CO-12, "Removal and Installation" .
2. Remove cooling fan. Refer to CO-15, "
Removal and Installation (Crankshaft Driven Type)" .
3. Remove the crankshaft pulley. Refer to EM-35, "
TIMING CHAIN" .
4. Remove the front oil seal using suitable tool.
CAUTION:
Do not damage front cover and oil pump drive spacer.
INSTALLATION
1. Apply new engine oil to both the oil seal lip and dust seal lip of the new front oil seal.
2. Install the front oil seal.

Install the front oil seal so that each seal lip is oriented as
shown.

Press-fit until the height of the front oil seal is level with the
mounting surface using suitable tool.
CAUTION:

Do not damage front timing chain case and crankshaft.

Press-fit straight and avoid causing burrs or tilting oil
seal.
3. Installation of the remaining components is in the reverse order of removal.
Removal and Installation of Rear Oil SealEBS00LMD
REMOVAL
1. Remove the transmission assembly. Refer to AT-244, "Removal and Installation (4x2)" or AT-247,
"Removal and Installation (4x4)" .
a. Remove the drive plate.

Holding the crankshaft pulley bolt, lock the crankshaft and remove the drive plate bolts.

Remove the bolts diagonally.
CAUTION:

Do not damage the drive plate. Especially, avoid deforming and damaging the signal plate
teeth (circumference position).

Place the drive plate with the signal plate surface facing other than downward.
SBIA0359E
SEM 71 5A
PBIC2931E

ENGINE ASSEMBLY
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Revision: October 20052005 QX56
ENGINE ASSEMBLYPFP:10001
Removal and InstallationEBS00LMI
WA RN ING:

Situate vehicle on a flat and solid surface.

Place chocks at front and back of rear wheels.

For engines not equipped with engine slingers, attach proper slingers and bolts described in
PA R T S C ATA L O G.
CAUTION:

Always be careful to work safely, avoid forceful or uninstructed operations.

Do not start working until exhaust system and engine coolant are cooled sufficiently.

If items or work required are not covered by the engine section, refer to the applicable sections.

Always use the support point specified for lifting.

Use either 2-point lift type or separate type lift. If board-on type is used for unavoidable reasons,
support at the rear axle jacking point with transmission jack or similar tool before starting work, in
preparation for the backward shift of center of gravity.

For supporting points for lifting and jacking point at rear axle, refer to GI-40, "Garage Jack and
Safety Stand" .
REMOVAL
Preparation
1. Drain the engine coolant. Refer to MA-13, "DRAINING ENGINE COOLANT" .
2. Partially drain the A/T fluid. Refer to MA-24, "
Changing A/T Fluid" .
3. Release the fuel pressure. Refer to EC-93, "
FUEL PRESSURE RELEASE" .
4. Remove the engine hood. Refer to BL-13, "
Removal and Installation of Hood Assembly" .
1. Rear engine mounting insulator 4x4 2. Rear engine mounting insulator 4x2 3. LH engine mounting bracket
4. LH heat shield plate 5. LH engine mounting insulator 6. RH engine mounting bracket
7. RH heat shield plate 8. RH engine mounting insulator
LBIA0397E

EM-70Revision: October 2005
ENGINE ASSEMBLY
2005 QX56
5. Remove the cowl extension. Refer to EI-18, "Removal and Installation" .
6. Remove the engine room cover using power tools.
7. Remove the air duct and air cleaner case assembly EM-14, "
REMOVAL" .
8. Disconnect the vacuum hose between the vehicle and engine and set it aside.
9. Remove the radiator assembly and hoses. Refer to CO-12, "
REMOVAL" .
10. Remove the drive belts. Refer to EM-12, "
Removal" .
11. Remove the fan blade. Refer to CO-15, "
REMOVAL" .
12. Disconnect the engine room harness from the fuse box and set it aside.
13. Disconnect the ECM.
14. Disconnect the engine room harness from the engine side and set it aside.
15. Disconnect the engine harness grounds.
16. Disconnect the power steering reservoir tank from the engine and move it aside.
17. Disconnect the power steering oil pump from the engine. Move it aside and secure it using suitable wire or
rope. Refer to PS-26, "
REMOVAL" .
18. Remove the A/C compressor bolts and set the compressor aside. Refer to ATC-179, "
REMOVAL" .
19. Disconnect the brake booster vacuum line.
20. Disconnect the EVAP line.
21. Disconnect the fuel hose at the engine side connection. Refer to EM-29, "
REMOVAL" .
22. Disconnect the heater hoses at cowl, and install plugs to avoid leakage of engine coolant.
23. Remove the A/T oil level indicator and indicator tube upper bolts.
24. Remove the front final drive assembly (4x4 only). Refer to FFD-11, "
REMOVAL" .
25. Remove the exhaust manifolds. Refer to EM-19, "
Removal and Installation" .
26. Install the engine slingers into the left bank cylinder head and
right bank cylinder head.
27. Remove the A/T. Refer to AT-244, "
Removal and Installation
(4x2)" or AT-247, "Removal and Installation (4x4)" .
28. Lift using hoist and secure the engine in position.
29. Remove the engine assembly from the vehicle, avoid interfer-
ence with the vehicle body.
CAUTION:

Before and during lifting, always check if any harnesses
are left connected.
30. Remove the parts that may restrict installation of the engine to the engine stand.
NOTE:
This procedure is described assuming that you use an engine stand mounting to the surface to which the
transmission mounts.
a. Remove the drive plate.

Holding the crankshaft pulley bolt, lock the crankshaft to remove the drive plate bolts.

Loosen the bolts diagonally.
WBIA0464E
Engine slinger torque: 45.0 N·m (4.6 kg-m, 33 ft-lb)
PBIC1556E

EM-72Revision: October 2005
ENGINE ASSEMBLY
2005 QX56
INSTALLATION
Installation is in the reverse order of removal.
CAUTION:

When replacing an engine or transmission you must make sure the dowels are installed correctly
during re-assembly.

Improper alignment caused by missing dowels may cause vibration, oil leaks or breakage of driv-
etrain components.
INSPECTION AFTER INSTALLATION

Before starting the engine, check oil/fluid levels including engine coolant and engine oil. If the levels are
lower than required quantity, fill to the specified level. Refer to MA-11, "
RECOMMENDED FLUIDS AND
LUBRICANTS" .

Use procedure below to check for fuel leakage.

Turn ignition switch ON (with engine stopped). With fuel pressure applied to the fuel piping, check for fuel
leakage at the connection points.

Start engine. With engine speed increased, check again for fuel leakage at connection points.

Run engine to check for unusual noise and vibration.

Warm up engine thoroughly to make sure there is no leakage of fuel, exhaust gas, or any oils/fluids includ-
ing engine oil and engine coolant.

Bleed air from passages in lines and hoses, such as in cooling system.

After cooling down the engine, again check oil/fluid levels including engine oil and engine coolant. Refill to
specified level if necessary.

Summary of the inspection items:
*Transmission/transaxle/CVT fluid, power steering fluid, brake fluid, etc.Item Before starting engine Engine running After engine stopped
Engine coolant Level Leakage Level
Engine oil Level Leakage Level
Other oils and fluids* Level Leakage Level
Fuel Leakage Leakage Leakage
Exhaust gas — Leakage —