2001 INFINITI QX4 Transfer Control Unit

Terminal
No.Wire color Item ConditionJudgement
standard
(Approx.)
39 W/BEngine speed
signal
Refer to EC-127, ªECM INSPECTION
TABLEº.Ð
40 W/LVehicle speed
sensor
When moving vehicle at 2 to 3 km/h (1 to 2
MPH) for1m(3ft)ormore.Voltage varies
between less
than 1.0V and
more than
4.5V.
41 PThrottle position
sensor
When depressing accelerator pedal slowly
after warming up engine.
(Voltage rises gradually in response to throttle
position.)Fully-closed
throttle:
0.5V - 0.7V
Fully-open
throttle:
4V
42 BThrottle position
sensor
(Ground)Ð0V
45 G/Y Stop lamp switchWhen depressing brake pedalBattery volt-
age
When releasing brake pedal 0V
46 WTransfer control
unitÐÐ
47 RA/T fluid tempera-
ture sensorWhen ATF temperature is 20ÉC (68ÉF). 1.5V
When ATF temperature is 80ÉC (176ÉF). 0.5V
48 B Ground
Ð0V
*1: These terminals are connected to the ECM.
*2: These terminals are connected to the Data link connector for CONSULT-II.
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TROUBLE DIAGNOSIS Ð GENERAL DESCRIPTION
TCM Terminals and Reference Value (Cont'd)
AT-95

SAT544J
SAT546J
Rear Oil Seal and Companion Flange Oil Seal
Replacement
NBAT0212Ð 2WD MODEL ÐNBAT0212S01NOTE:
Replace rear extension assembly as a single unit because it can-
not be disassembled.
1. Remove propeller shaft. Refer to PD-4, ªComponentsº.
2. Remove exhaust mounting and mounting bracket.
3. Disconnect revolution and speedometer sensor harness con-
nector.
4. Support A/T assembly with a jack.
5. Remove rear engine mounting member. Tighten rear engine
mounting member to the specified torque. Refer to EM-59,
ªRear Engine Mountingº.
6. Remove rear extension assembly.
a. Remove parking gear and needle bearing.
CAUTION:
Insert your hand between rear extension and transmission
case. Detach rear extension assembly while holding parking
gear and needle bearing by hand.
7. Reinstall any part removed.
IAlways use new sealing parts.
SAT083J
Parking Components InspectionNBAT0213Ð 4WD MODEL ÐNBAT0213S011. Remove propeller shaft. Refer to PD-4, ªComponentsº.
2. Remove transfer case from vehicle. Refer to TF-119, ªRemovalº.
3. Remove A/T control cable bracket from transmission case.
SAT078B
4. Support A/T assembly with a jack.
5. Remove adapter case from transmission case.
6. Replace parking components if necessary.
7. Reinstall any part removed.
IAlways use new sealing parts.
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ON-VEHICLE SERVICE
Rear Oil Seal and Companion Flange Oil Seal Replacement
AT-275

8. Vehicle Vibrates Excessively When ABS Is
Operating
=NBBR0078IWhile ABS is operating, brake pedal vibrates slightly. This is
not a problem.
IIf vehicle vibration is greater in the AUTO mode than in the
2WD mode, there is the possibility of failure in the communi-
cation line between the ABS control unit and transfer control
unit. Check and locate the cause of the problem.
1 INSPECTION START
Inspection for excessive vibration of vehicle
SBR508E
©GO TO 2.
2 CARRY OUT SELF-DIAGNOSIS
Perform self-diagnosis for the ABS actuator and electric unit and transfer control unit.
Are there any malfunctions?
Ye s©GO TO 3.
No©GO TO 4.
3 INSPECTION OR REPAIR
Inspect or repair the system according to the self-diagnostic item.
OK©GO TO 4.
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TROUBLE DIAGNOSES FOR SYMPTOMSABS
8. Vehicle Vibrates Excessively When ABS Is Operating
BR-77

4 CHECK CIRCUIT
1. Disconnect connectors from ABS actuator and electric unit and transfer control unit. Check terminals for damage or
loose connection.
2. Check continuity between ABS actuator and electric unit connector terminal 13 and transfer control unit connector ter-
minal 32.
SBR509E
Does continuity exist?
Ye s©GO TO 5.
No©Check the following.
IHarness connectors E111, M143
IHarness for open or short between ABS actuator and electric unit and transfer control
unit
If NG, repair harness or connectors.
5 CHECK ABS OPERATING SIGNAL CIRCUIT
1. Reconnect only ABS actuator and electric unit connector.
2. Check continuity between transfer control unit connector terminal 32 and ground.
Continuity should not exist.
SBR510E
Does continuity exist?
Ye s©Replace ABS actuator and electric unit.
No©GO TO 6.
TROUBLE DIAGNOSES FOR SYMPTOMSABS
8. Vehicle Vibrates Excessively When ABS Is Operating (Cont'd)
BR-78

6 CHECK ABS OPERATING SIGNAL
1. Connect CONSULT-II to Data Link Connector.
2. Turn ignition switch ªONº. Set CONSULT-II in the active test mode to output an ABS operating signal.
(Refer to ªACTIVE TEST PROCEDUREº, ªCONSULT-II Inspection Procedureº, BR-47.)
3. An ABS operating signal lasts for 10 seconds. During the time the signal is being output, check resistance between
transfer control unit connector terminal 32 and ground.
Resistance: 0.5W, max.
SBR680E
Is resistance within specifications?
Ye s©CHECK transfer control unit.
Refer to TF-86, ªTROUBLE DIAGNOSIS FOR ABS OPERATION SIGNALº.
No©Replace ABS actuator and electric unit.
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TROUBLE DIAGNOSES FOR SYMPTOMSABS
8. Vehicle Vibrates Excessively When ABS Is Operating (Cont'd)
BR-79

GENERAL INFORMATION
SECTION
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CONTENTS
PRECAUTIONS...............................................................3
Precautions ..................................................................3
PRECAUTIONS FOR SUPPLEMENTAL
RESTRAINT SYSTEM (SRS)²AIR BAG²AND
²SEAT BELT PRE-TENSIONER²
.................................3
PRECAUTIONS FOR IVIS (INFINITI VEHICLE
IMMOBILIZER SYSTEM - NATS)
.................................3
PRECAUTIONS FOR INFINITI COMMUNICATOR
(IVCS)
.......................................................................4
GENERAL PRECAUTIONS.........................................5
PRECAUTIONS FOR MULTIPORT FUEL
INJECTION SYSTEM OR ENGINE CONTROL
SYSTEM
...................................................................6
PRECAUTIONS FOR THREE WAY CATALYST...........6
PRECAUTIONS FOR HOSES.....................................7
PRECAUTIONS FOR ENGINE OILS...........................8
PRECAUTIONS FOR FUEL........................................8
PRECAUTIONS FOR AIR CONDITIONING..................8
HOW TO USE THIS MANUAL........................................9
HOW TO READ WIRING DIAGRAMS.......................... 11
Sample/Wiring Diagram - EXAMPL - ........................ 11
OPTIONAL SPLICE..................................................12
Description .................................................................13
CONNECTOR SYMBOLS.........................................15
HARNESS INDICATION...........................................16
COMPONENT INDICATION......................................16
SWITCH POSITIONS...............................................16
DETECTABLE LINES AND NON-DETECTABLE
LINES
.....................................................................17
MULTIPLE SWITCH.................................................18
REFERENCE AREA.................................................19
HOW TO CHECK TERMINAL.......................................21
Connector and Terminal Pin Kit.................................21
How to Probe Connectors .........................................21
PROBING FROM HARNESS SIDE............................21
PROBING FROM TERMINAL SIDE...........................21
How to Check Enlarged Contact Spring of
Terminal .....................................................................22
Waterproof Connector Inspection ..............................23
RUBBER SEAL INSPECTION...................................23
WIRE SEAL INSPECTION........................................23Terminal Lock Inspection ...........................................23
HOW TO PERFORM EFFICIENT DIAGNOSIS
FOR AN ELECTRICAL INCIDENT...............................24
Work Flow ..................................................................24
Incident Simulation Tests ...........................................25
INTRODUCTION......................................................25
VEHICLE VIBRATION..............................................25
HEAT SENSITIVE....................................................26
FREEZING..............................................................26
WATER INTRUSION................................................27
ELECTRICAL LOAD.................................................27
COLD OR HOT START UP.......................................27
Circuit Inspection .......................................................27
INTRODUCTION......................................................27
TESTING FOR²OPENS²IN THE CIRCUIT................28
TESTING FOR²SHORTS²IN THE CIRCUIT..............29
GROUND INSPECTION...........................................30
VOLTAGE DROP TESTS..........................................30
CONTROL UNIT CIRCUIT TEST...............................32
HOW TO FOLLOW TROUBLE DIAGNOSIS................34
How to Follow Test Groups in Trouble Diagnosis .....35
Key to Symbols Signifying Measurements or
Procedures.................................................................36
CONSULT-II CHECKING SYSTEM...............................38
Function and System Application ..............................38
Nickel Metal Hydride Battery Replacement...............39
Checking Equipment..................................................39
CONSULT-II Data Link Connector (DLC) Circuit ......40
INSPECTION PROCEDURE.....................................40
IDENTIFICATION INFORMATION................................41
Model Variation ..........................................................41
PREFIX AND SUFFIX DESIGNATIONS.....................41
Identification Number .................................................41
VEHICLE IDENTIFICATION NUMBER
ARRANGEMENT
.....................................................42
IDENTIFICATION PLATE..........................................42
ENGINE SERIAL NUMBER.......................................43
AUTOMATIC TRANSMISSION NUMBER...................43
TRANSFER SERIAL NUMBER..................................43
Dimensions ................................................................43
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ECM input/output signal ...............................EC-127
ECTS - Wiring diagram ........................EC-171, 189
Electric sun roof ............................................EL-173
Electrical diagnoses.........................................GI-24
Electrical ignition system ................................EC-30
Electrical unit ................................................Foldout
Electrical units location .................................EL-436
Engine compartment .......................................BT-58
Engine control circuit diagram........................EC-24
Engine control component parts
location .......................................................EC-20
Engine control module (ECM) ......................EC-444
Engine control system diagram and
chart ............................................................EC-25
Engine coolant temperature sensor
(ECTS) ..............................................EC-169, 187
Engine fail-safe system ................................EC-117
Engine oil filter replacement ..........................MA-18
Engine oil precautions .......................................GI-8
Engine oil replacement ..................................MA-18
Engine outer component parts ......................EM-10
Engine removal ..............................................EM-57
Engine room - See Engine
compartment................................................BT-58
Engine serial number ......................................GI-43
EVAP canister.................................................EC-33
EVAP canister purge volume control
solenoid valve.............................EC-32, 367, 541
EVAP canister vent control
valve .........................................EC-374, 553, 573
EVAP control system (small leak)
diagnosis ..................................EC-352, 394, 526
EVAP control system pressure sensor.........EC-381
EVAP control system purge flow moni-
toring diagnosis.........................................EC-561
EVAP vapor lines inspection ..........................MA-20
Evaporative emission (EVAP) system ............EC-32
Exhaust system ................................................FE-8
Exhaust system inspection ............................MA-21
Exterior ............................................................BT-35
F
4LO indicator lamp........................................TF-104
4WD shift indicator lamp.................................TF-98
4WD shift switch ............................................TF-111
4WD solenoid valve.......................................TF-111
4WD warning lamp .........................................TF-13
Fan control amp. ............................................HA-98
F/FOG - Wiring diagram .................................EL-72
Final drive disassembly ..................................PD-43
Final drive pre-inspection ...............................PD-43
Final drive removal and installation ...............PD-43
Finisher, interior - See Trim ............................BT-28
F/LID - Wiring diagram .................................EL-180
Fluid temperature sensor (A/T) .....................AT-110Fluids ..............................................................MA-11
Flywheel runout..............................................EM-70
FO2H-L - Wiring diagram .............................EC-243
FO2H-R - Wiring diagram ............................EC-242
Fog lamp, front................................................EL-70
Fog lamp, front, removal and
installation ...................................................BT-12
Forward clutch ...............................................AT-320
F/PUMP - Wiring diagram ............................EC-627
Freeze frame data ..........................................EC-60
FRO2LH - Wiring diagram ...........EC-197, 223, 235
FRO2RH - Wiring diagram...........EC-196, 222, 234
Front axle..........................................................AX-2
Front bumper ..................................................BT-12
Front case (Transfer) ....................................TF-133
Front combination lamp removal and
installation ...................................................BT-12
Front disc brake .............................................BR-22
Front door .......................................................BT-18
Front drive shaft (Transfer) ...........................TF-125
Front final drive disassembly (4WD) ..............PD-18
Front final drive pre-inspection (4WD) ...........PD-18
Front final drive removal and installa-
tion (4WD)...................................................PD-18
Front fog lamp.................................................EL-70
Front fog lamp removal and installation .........BT-12
Front heated oxygen sensor (HO2S)
(Left bank) ................EC-192, 202, 210, 218, 231
Front heated oxygen sensor (HO2S)
(Right bank) .............EC-192, 202, 210, 218, 231
Front heated oxygen sensor heater
(Left bank).................................................EC-240
Front heated oxygen sensor heater
(Right bank) ..............................................EC-240
Front revolution sensor (Transfer) ................TF-112
Front seat ........................................................BT-41
Front seat belt ..................................................RS-4
Front suspension ..............................................SU-2
Front washer .................................................EL-136
Front wiper ....................................................EL-136
Fuel cut control (at no load & high
engine speed) .............................................EC-32
Fuel filler lid.....................................................BT-15
Fuel filter replacement ...................................MA-16
Fuel gauge ......................................................EL-94
Fuel injection system (Left bank) .........EC-294, 302
Fuel injection system (Right bank) ......EC-294, 302
Fuel lid opener, electric.................................EL-180
Fuel line inspection ........................................MA-16
Fuel precautions ................................................GI-8
Fuel pressure check .......................................EC-39
Fuel pressure regulator ..................................EC-40
Fuel pressure release ....................................EC-39
Fuel pump ....................................................EC-625
Fuel system ......................................................FE-4
Fuel tank temperature sensor ......................EC-309
Fuel tank vacuum relief valve ........................EC-33
FUELLH - Wiring diagram....................EC-297, 305
FUELRH - Wiring diagram ...................EC-296, 304
Fuse ................................................................EL-16
Fuse block ....................................................Foldout
ALPHABETICAL INDEX
IDX-4

Fusible link ......................................................EL-16
G
Garage jack and safety stand .........................GI-46
Gauges............................................................EL-94
Generator - See Alternator .............................SC-28
Generic scan tool (GST) ................................EC-95
Glass ...............................................................BT-18
Glass hatch opener, electric .........................EL-178
Grease ............................................................MA-11
Ground distribution..........................................EL-17
H
Harness connector ............................................EL-5
Harness connector inspection .........................GI-21
Harness layout ..............................................EL-440
Hazard warning lamp ......................................EL-75
Headlamp ........................................................EL-31
Headlamp aiming control ................................EL-59
Headlining - See Roof trim .............................BT-32
Heated seat .......................................BT-43, EL-183
Height (Dimensions) ........................................GI-43
HFC134a (R134a) system precaution .............HA-2
HFC134a (R134a) system service
procedure ..................................................HA-144
HFC134a (R134a) system service tools ........HA-11
HFC134a system service equipment
precaution .....................................................HA-7
High clutch.....................................................AT-317
H/LAMP - Wiring diagram ...............................EL-36
Hood................................................................BT-12
Horn ..............................................................EL-147
HORN - Wiring diagram................................EL-147
How to erase DTC for OBD system...............EC-72
HSEAT - Wiring diagram...............................EL-183
I
IACV-AAC valve ...........................................EC-422
IATS - Wiring diagram ..................................EC-166
Identification .....................................................HA-4
Identification plate............................................GI-42
Idle air control valve (IACV) .........................EC-422
Idle mixture ratio.............................................EC-43
Idle speed .......................................................EC-43
IGN/SG - Wiring diagram .............................EC-501
Ignition control system .................................EC-499
Ignition timing .................................................EC-43
ILL - Wiring diagram .......................................EL-83
Illumination ......................................................EL-80
In vehicle sensor ..........................................HA-132
INFINITI COMMUNICATOR..........................EL-348
Infiniti communicator (IVCS) .........................EL-348
INJECT - Wiring diagram .............................EC-617
Injector ..........................................................EC-616Injector removal and installation ....................EC-41
Instrument panel .............................................BT-21
INT/L - Wiring diagram....................................EL-91
Intake air temparature sensor ......................EC-164
Intake door control linkage adjustment ..........HA-94
Intake door motor ...........................................HA-87
Intake manifold...............................................EM-12
Intake sensor ................................................HA-139
Integrated homelink transmitter ....................EL-325
Interior .............................................................BT-28
Interior lamp ....................................................EL-88
Interior lamp on-off control ..............................EL-89
Internal gear (Transfer) .................................TF-134
IVC-L - Wiring diagram.................................EC-453
IVC-R - Wiring diagram ................................EC-453
IVCS - Wiring diagram ..................................EL-359
IVCS-L - Wiring diagram ..............................EC-485
IVCS-R - Wiring diagram .............................EC-485
IVIS (Infiniti vehicle immobilizer
system) ......................................................EL-328
IVIS (Infiniti vehicle immobilizer sys-
tem) precautions ............................................GI-3
J
Jacking points ..................................................GI-45
Journal bearing assembly (propeller
shaft) .............................................................PD-9
Journal bearing disassembly (propeller
shaft) .............................................................PD-8
Junction box (J/B).........................................Foldout
K
Keyless entry system - See Multi-re-
mote control system ..................................EL-270
Knock sensor (KS) .......................................EC-328
Knuckle spindle ................................................AX-9
KS - Wiring diagram .....................................EC-330
L
Length (Dimensions) .......................................GI-43
License lamp ...................................................EL-61
Lifting points ....................................................GI-47
Limited slip diff. adjustment ............................PD-50
Limited slip diff. assembly ..............................PD-51
Limited slip diff. disassembly..........................PD-48
Limited slip diff. inspection .............................PD-49
Line pressure solenoid valve ........AT-147, 161, 167
Line pressure switch (Transfer) .....................TF-111
Line pressure test (A/T) ..................................AT-62
Liquid gasket application .................................EM-3
LOAD - Wiring diagram ................................EC-643
Location of electrical units ............................EL-436
Lock, door .......................................................BT-18
Low and reverse brake .................................AT-324
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ALPHABETICAL INDEX
IDX-5