Air INFINITI QX56 2004 Factory Service Manual

TF-94
TROUBLE DIAGNOSES FOR SYMPTOMS
Revision: August 20072004 QX56
Symptom 9. 4WD System Does Not Operate (The Vehicle Cannot Be Put Into
4WD Mode-Hydraulic System Failure)
EDS0018M
1. CHECK INPUT SIGNAL
With CONSULT-II
1. Select “ECU INPUT SIGNALS” in Data Monitor.
2. Put A/T selector lever in D.
3. Turn 4WD shift switch to 4H and back to 2WD while reading out
ON/OFF status of "CL PRES SW".
Without CONSULT-II
Check voltage between transfer control unit harness connector E143
terminal 34 (BR) and ground.
Refer to TF-55, "
TRANSFER CONTROL UNIT INSPECTION
TABLE" .
OK or NG
OK >> 1. Check transfer fluid level.
2. Disassemble transfer unit and check the following.
–Transfer motor
–Main oil pump assembly
–Sub-oil pump assembly
–Oil strainer
–Control valve assembly
–2-4WD shift solenoid valve
–Oil filter element
–Lip seal
–Strainer O-ring
–Main oil pump drive gear
–Seal ring
–D-ring
–Clutch piston
–Clutch assembly
NG >> GO TO 2.
2. CHECK CLUTCH PRESSURE CIRCUIT
Check clutch pressure switch circuit.
Refer to TF-72, "
Diagnostic Procedure" .
OK or NG
OK >> GO TO 3.
NG >> Check, repair or replace faulty parts.
3. CHECK PROCEDURES FROM THE BEGINNING
Check again.
OK or NG
OK >> Inspection End.
NG >> Recheck each connector pin terminals for damage or loose connection.
WDIA0087E

AIR BREATHER HOSE
TF-105
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TF
Revision: August 20072004 QX56
AIR BREATHER HOSEPFP:31098
Removal and InstallationEDS00319
Refer to the figure for air breather hose removal and installation information.
CAUTION:

Make sure there are no pinched or restricted areas on the air breather hose caused by bending or
winding when installing it.

Install the air breather hose into the air breather (metal connector) and actuator (case connector)
until the hose end reaches the base of the tube.

Install the air breather hose into the breather tube (metal connector) and transfer motor (case con-
nector) until the hose end reaches the end of the curved section.
SDIA2656E

OVERHAUL
TF-111
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TF
Revision: August 20072004 QX56
46. Snap ring 47. Retaining pin 48. L-H fork
49. 2-4 fork 50. Shift fork spring 51. Fork guide
52. Retainer pin 53. Shift rod
1. Dust cover 2. Oil seal 3. Rear case
4. Air breather 5. Seal ring 6. Main oil pump cover
7. Inner gear 8. Outer gear 9. Main oil pump housing
10. D-ring 11. D-ring 12. Clutch piston
13. Thrust needle bearing race 14. Oil strainer 15. O-ring
16. Snap ring 17. Control valve assembly 18. Lip seal (7 pieces)
19. Washer 20. Filler plug 21. Filler stud
22. O-ring 23. Oil filter 24. ATP switch
25 Neutral-4LO switch 26. Oil pressure check plug 27. Harness bracket
28. Stem bleeder 29. Harness bracket 30. Center case
31. Mainshaft rear bearing 32. C-ring 33. Washer holder
34. Snap ring 35. Sub oil pump housing 36. Outer gear
37. Inner gear 38. Sub oil pump cover 39. O-ring
40. Transfer motor 41. Connector bracket
SDIA2091E

TF-112
REAR CASE
Revision: August 20072004 QX56
REAR CASEPFP:33102
DisassemblyEDS0018Y
1. Remove rear case bolts.
2. Remove rear case from center case, using suitable tool.
3. Remove the dust cover, using suitable tool.
4. Remove the oil seal, using suitable tool.
CAUTION:
Be careful not to damage the rear case.
5. Remove the air breather.
SDIA2092E
SDIA2093E
SDIA2094E
SDIA2095E

TF-118
CENTER CASE
Revision: August 20072004 QX56
10. Tap mainshaft, using suitable tool to remove it from clutch drum
and clutch hub.
11. Remove needle bearing and spacer from the mainshaft.
12. Remove the snap ring from the clutch hub.
CLUTCH PISTON
1. Remove oil pressure check plug from oil pressure check port.
2. Apply air gradually from oil pressure check port, and remove
clutch piston from center case.
SMT914C
WDIA0101E
SDIA2 115 E
SDIA2 116 E

TF-142
CENTER CASE
Revision: August 20072004 QX56
CONTROL VALVE
1. Clean upper body, control valves and springs with cleaning agent, and dry with compressed air.
2. Dip control valves in ATF, and apply ATF to the valve-mounting area of upper body.
3. Install each control valve (3), spring (4) and plug (2) to upper
body (5), and install retainer plates (1) to hold them in place.
CAUTION:

To insert control valves into upper body, place upper
body on a level surface in order to prevent flaw or dam-
age.

Make sure each control valve is smoothly inserted.
4. Install reverse balls, relief balls and relief springs, accumulator
pistons and valve springs to upper body.
5. Install lower body and separator plate to upper body.
NOTE:
Do not reuse separator plates.
WDIA0284E
SDIA2127E
SDIA2126E
SDIA2125E

TF-150
ASSEMBLY
Revision: August 20072004 QX56
4. Install center case assembly to front case assembly.
CAUTION:
Pay careful attention so that mainshaft end is not damaged.
5. Tap center case lightly press-fit front drive shaft bearing into
front case, using suitable tool.
6. Tighten front case bolts to specified torque.
NOTE:
Be sure to install air breather hose clamp, connector bracket
and harness clip.
7. Remove all the gasket fluid from switch mounting area and
inside center case. With ATP switch and neutral-4LO switch
threaded in 1 to 2 pitches, apply specified sealant or equivalent
to the thread of the switches and tighten to specified torque.
Refer to GI-45, "
Recommended Chemical Products and Seal-
ants" .
8. Apply ATF or petroleum jelly to stem bleeder and install to center
case.
9. Install main oil pump assembly to the center case assembly and tighten bolts. Refer to TF-110, "
Transfer
Components" .
SDIA2138E
Front case bolts : 45 N·m (4.6 kg-m, 33 ft-lb)
SDIA2100E
ATP and Neutral- 4LO
switches: 28 N·m (2.9 kg-m, 21 ft-lb)
SDIA2096E
SDIA2097E

TF-152
ASSEMBLY
Revision: August 20072004 QX56
15. Install air breather into rear case.
16. Apply specified Anaerobic Liquid Gasket or equivalent to entire
rear case mounting surface of center case as shown. Refer to
GI-45, "
Recommended Chemical Products and Sealants" .
CAUTION:
Be careful not to allow Liquid Gasket to the stem bleeder
hole.
NOTE:
Remove all foreign materials such as water, oil, and grease from
center case and rear case mating surfaces.
17. Install rear case to center case, and tighten bolts to specified
torque.
18. Installation of the remaining components is in the reverse order of removal.
SDIA2206E
Center case bolts : 45 N·m 4.6 kg-m, 33 ft-lb)
SDIA2100E

WT-1
ROAD WHEELS & TIRES
E SUSPENSION
CONTENTS
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SECTION WT
A
B
WT
Revision: August 20072004 QX56 PREPARATION ........................................................... 2
Special Service Tool ................................................. 2
Commercial Service Tools ........................................ 2
NOISE, VIBRATION, AND HARSHNESS (NVH)
TROUBLESHOOTING ................................................ 3
NVH Troubleshooting Chart ..................................... 3
WHEEL ....................................................................... 4
Inspection ................................................................. 4
WHEEL AND TIRE ASSEMBLY ................................. 5
Balancing Wheels .................................................... 5
REMOVAL ............................................................. 5
WHEEL BALANCE ADJUSTMENT ...................... 5
Rotation .................................................................... 6
LOW TIRE PRESSURE WARNING SYSTEM ............ 7
System Components ................................................ 7
System Description .................................................. 7
TRANSMITTER ..................................................... 7
REMOTE KEYLESS ENTRY RECEIVER ............. 7
BCM (BODY CONTROL MODULE) ...................... 8
LOW TIRE PRESSURE WARNING LAMP AND
BUZZER ................................................................ 8
DISPLAY UNIT ...................................................... 8
CAN COMMUNICATION ............................................ 9
System Description .................................................. 9
TROUBLE DIAGNOSES .......................................... 10
Wiring Diagram — T/WARN — .............................. 10
Terminal and Reference Value (BCM) .................... 12
ID Registration Procedure ...................................... 13
ID REGISTRATION WITH TRANSMITTER
ACTIVATION TOOL ............................................ 13
ID REGISTRATION WITHOUT TRANSMITTER
ACTIVATION TOOL ............................................ 14
Transmitter Wake Up Operation ............................. 15
............................................................................ 15
CONSULT-II Function (BCM) ................................. 16
Self-Diagnosis ........................................................ 17
DESCRIPTION .................................................... 17
FUNCTION .......................................................... 17CONSULT-II ......................................................... 17
How to Perform Trouble Diagnosis for Quick and
Accurate Repair ...................................................... 19
INTRODUCTION ................................................. 19
WORK FLOW ...................................................... 19
Preliminary Check .................................................. 20
Malfunction Code/Symptom Chart .......................... 21
TROUBLE DIAGNOSIS FOR SELF-DIAGNOSTIC
ITEMS ........................................................................ 23
Inspection 1: Transmitter or Control Unit (BCM) ..... 23
MALFUNCTION CODE NO. 21, 22, 23 OR 24 ... 23
Inspection 2: Transmitter - 1 ................................... 23
MALFUNCTION CODE NO. 31, 32, 33, 34, 41,
42, 43, 44, 45, 46, 47 OR 48 ............................... 23
Inspection 3: Transmitter - 2 ................................... 24
MALFUNCTION CODE NO. 35, 36, 37 OR 38 ... 24
Inspection 4: Vehicle Speed Signal ........................ 25
MALFUNCTION CODE NO. 52 ........................... 25
TROUBLE DIAGNOSIS FOR SYMPTOMS .............. 26
Inspection 1: Low Tire Pressure Warning Lamp
Does Not Come On When Ignition Switch Is Turned
On ........................................................................... 26
Inspection 2: Low Tire Pressure Warning Lamp
Stays On When Ignition Switch Is Turned On ......... 26
Inspection 3: Low Tire Pressure Warning Lamp
Flashes When Ignition Switch Is Turned On .......... 28
Inspection 4: Hazard Warning Lamp Flashes When
Ignition Switch Is Turned On .................................. 29
Inspection 5: “TIRE PRESSURE” Information In
Display Unit Does Not Exist .................................... 30
Inspection 6: ID Registration Cannot Be Completed ... 30
REMOVAL AND INSTALLATION ............................. 31
Transmitter (Pressure Sensor) ............................... 31
REMOVAL ........................................................... 31
INSTALLATION ................................................... 31
SERVICE DATA AND SPECIFICATIONS (SDS) ...... 33
Road Wheel ............................................................ 33
Tire ......................................................................... 33

NOISE, VIBRATION, AND HARSHNESS (NVH) TROUBLESHOOTING
WT-3
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Revision: August 20072004 QX56
NOISE, VIBRATION, AND HARSHNESS (NVH) TROUBLESHOOTINGPFP:00003
NVH Troubleshooting ChartEES00122
Use the chart below to help you find the cause of the symptom. If necessary, repair or replace these parts.
×: ApplicableReference page
WT-4WT-5WT-33WT-6—
—
WT-33
RFD-5, "
NVH Troubleshooting Chart
" (FFD),
RFD-5, "
NVH Troubleshooting Chart
" (RFD)
FAX -4, "
NVH Troubleshooting Chart
" (FAX),
FSU-4, "
NVH Troubleshooting Chart
" (FSU)
RAX-4, "
NVH Troubleshooting Chart
" (RAX),
RSU-5, "
NVH Troubleshooting Chart
" (RSU)
Refer to TIRES in this chart.
Refer to ROAD WHEEL in this chart.
BR-5, "
NVH Troubleshooting Chart
"
PS-5, "
NVH Troubleshooting Chart
"
Possible cause and SUSPECTED PARTS
Out-of-round
Imbalance
Incorrect tire pressure
Uneven tire wear
Deformation or damage
Non-uniformity
Incorrect tire size
DIFFERENTIAL
FRONT AXLE AND FRONT SUSPENSION
REAR AXLE AND REAR SUSPENSION
TIRES
ROAD WHEEL
BRAKE
STEERING
SymptomTIRESNoise× ××××× × × × × ××
Shake××××× × ××× ××
Vibration××××××
Shimmy× ×××××× × × × ××
Shudder××××× × ××× ××
Poor quality ride or
handling××××× × ×××
ROAD
WHEELNoise×× × ××× ×××
Shake×× × ×× ×××
Shimmy, shudder×× × ×× ×××
Poor quality ride or
handling×× × ×× ×