2001 INFINITI QX4 light

Component Inspection .............................................131
DTC P0733 IMPROPER SHIFTING TO 3RD GEAR
POSITION....................................................................132
Description ...............................................................132
Wiring Diagram - AT - 3RD......................................135
Diagnostic Procedure ..............................................136
Component Inspection .............................................137
DTC P0734 IMPROPER SHIFTING TO 4TH GEAR
POSITION....................................................................138
Description ...............................................................138
Wiring Diagram - AT - 4TH ......................................142
Diagnostic Procedure ..............................................143
Component Inspection .............................................147
DTC P0740 TORQUE CONVERTER CLUTCH
SOLENOID VALVE......................................................148
Description ...............................................................148
Wiring Diagram - AT - TCV......................................150
Diagnostic Procedure ..............................................151
Component Inspection .............................................152
DTC P0744 IMPROPER LOCK-UP OPERATION......153
Description ...............................................................153
Wiring Diagram - AT - TCCSIG ...............................156
Diagnostic Procedure ..............................................157
Component Inspection .............................................161
DTC P0745 LINE PRESSURE SOLENOID VALVE...162
Description ...............................................................162
Wiring Diagram - AT - LPSV....................................164
Diagnostic Procedure ..............................................165
Component Inspection .............................................167
DTC P0750 SHIFT SOLENOID VALVE A..................168
Description ...............................................................168
Wiring Diagram - AT - SSV/A ..................................169
Diagnostic Procedure ..............................................170
Component Inspection .............................................171
DTC P0755 SHIFT SOLENOID VALVE B..................172
Description ...............................................................172
Wiring Diagram - AT - SSV/B ..................................173
Diagnostic Procedure ..............................................174
Component Inspection .............................................175
DTC P1705 THROTTLE POSITION SENSOR...........176
Description ...............................................................176
Wiring Diagram - AT - TPS ......................................179
Diagnostic Procedure ..............................................180
Component Inspection .............................................184
DTC P1760 OVERRUN CLUTCH SOLENOID
VALVE..........................................................................185
Description ...............................................................185
Wiring Diagram - AT - OVRCSV..............................187
Diagnostic Procedure ..............................................188
Component Inspection .............................................189
DTC BATT/FLUID TEMP SEN (A/T FLUID TEMP
SENSOR CIRCUIT AND TCM POWER SOURCE)....190Description ...............................................................190
Wiring Diagram - AT - BA/FTS ................................192
Diagnostic Procedure ..............................................193
Component Inspection .............................................196
DTC VEHICLE SPEED SENSOR.MTR.......................197
Description ...............................................................197
Wiring Diagram - AT - VSSMTR ..............................199
Diagnostic Procedure ..............................................200
DTC TURBINE REVOLUTION SENSOR....................202
Description ...............................................................202
Wiring Diagram - AT - TRSA/T ................................204
Diagnostic Procedure ..............................................205
Component Inspection .............................................206
DTC A/T COMMUNICATION LINE.............................207
Description ...............................................................207
Wiring Diagram - AT - LAN ......................................209
Diagnostic Procedure ..............................................210
DTC CONTROL UNIT (RAM), CONTROL UNIT
(ROM)........................................................................... 211
Description ............................................................... 211
Diagnostic Procedure ..............................................212
DTC CONTROL UNIT (EEP ROM).............................213
Description ...............................................................213
Diagnostic Procedure ..............................................214
TROUBLE DIAGNOSES FOR SYMPTOMS...............215
Wiring Diagram - AT - NONDTC .............................215
1. O/D OFF Indicator Lamp Does Not Come On....218
2. Engine Cannot Be Started In²P²and²N²
Position ....................................................................221
3. In²P²Position, Vehicle Moves Forward Or
Backward When Pushed .........................................222
4. In²N²Position, Vehicle Moves ...........................223
5. Large Shock.²N²->²R²Position .......................225
6. Vehicle Does Not Creep Backward In²R²
Position ....................................................................227
7. Vehicle Does Not Creep Forward In²D²,²2²
Or²1²Position .........................................................230
8. Vehicle Cannot Be Started From D
1...................233
9. A/T Does Not Shift: D
1-> D2Or Does Not
Kickdown: D
4-> D2..................................................236
10. A/T Does Not Shift: D
2-> D3.............................239
11. A/T Does Not Shift: D
3-> D4.............................242
12. A/T Does Not Perform Lock-up .........................245
13. A/T Does Not Hold Lock-up Condition ..............247
14. Lock-up Is Not Released ...................................249
15. Engine Speed Does Not Return To Idle (Light
Braking D
4-> D3).....................................................250
16. Vehicle Does Not Start From D
1.......................252
17. A/T Does Not Shift: D
4-> D3, When
Overdrive Control Switch²ON²->²OFF²...............253
18. A/T Does Not Shift: D
3-> 22, When Selector
Lever²D²->²2²Position.........................................254
CONTENTS(Cont'd)
AT-2

Precautions for Supplemental Restraint System
(SRS) ªAIR BAGº and ªSEAT BELT
PRE-TENSIONERº
NBAT0001The supplemental Restraint System such as ªAIR BAGº and ªSEAT BELT PRE-TENSIONERº used along with
a seat belt, helps to reduce the risk or severity of injury to the driver and front passenger for certain types of
collision. The SRS system composition which is available to INFINITI QX4 is as follows:
IFor a frontal collision
The Supplemental Restraint System consists of driver air bag module (located in the center of the steer-
ing wheel), front passenger air bag module (located on the instrument panel on passenger side), seat belt
pre-tensioners, a diagnosis sensor unit, warning lamp, wiring harness and spiral cable.
IFor a side collision
The Supplemental Restraint System consists of front side air bag module (located in the outer side of front
seat), satellite sensor, diagnosis sensor unit (one of components of air bags for a frontal collision), wiring
harness, warning lamp (one of components of air bags for a frontal collision).
Information necessary to service the system safely is included in theRS sectionof this Service Manual.
WARNING:
ITo avoid rendering the SRS inoperative, which could increase the risk of personal injury or death
in the event of a collision which would result in air bag inflation, all maintenance must be performed
by an authorized INFINITI dealer.
IImproper maintenance, including incorrect removal and installation of the SRS, can lead to per-
sonal injury caused by unintentional activation of the system. For removal of Spiral Cable and Air
Bag Module, see the RS section.
IDo not use electrical test equipment on any circuit related to the SRS unless instructed to in this
Service Manual. Spiral cable and wiring harnesses covered with yellow insulation tape either just
before the harness connectors or for the complete harness are related to the SRS.
Precautions for On Board Diagnostic (OBD)
System of A/T and Engine
NBAT0002The ECM has an on board diagnostic system. It will light up the malfunction indicator lamp (MIL) to warn the
driver of a malfunction causing emission deterioration.
CAUTION:
IBe sure to turn the ignition switch ªOFFº and disconnect the negative battery terminal before any
repair or inspection work. The open/short circuit of related switches, sensors, solenoid valves, etc.
will cause the MIL to light up.
IBe sure to connect and lock the connectors securely after work. A loose (unlocked) connector will
cause the MIL to light up due to an open circuit. (Be sure the connector is free from water, grease,
dirt, bent terminals, etc.)
IBe sure to route and secure the harnesses properly after work. Interference of the harness with a
bracket, etc. may cause the MIL to light up due to a short circuit.
IBe sure to connect rubber tubes properly after work. A misconnected or disconnected rubber tube
may cause the MIL to light up due to a malfunction of the EGR system or fuel injection system,
etc.
IBe sure to erase the unnecessary malfunction information (repairs completed) from the TCM and
ECM before returning the vehicle to the customer.
SEF289H
PrecautionsNBAT0003IBefore connecting or disconnecting the TCM harness
connector, turn ignition switch ªOFFº and disconnect
negative battery terminal. Failure to do so may damage
the TCM. Because battery voltage is applied to TCM even
if ignition switch is turned ªOFFº.
PRECAUTIONS
Precautions for Supplemental Restraint System (SRS) ªAIR BAGº and ªSEAT BELT PRE-TENSIONERº
AT-6

SAT964I
Malfunction Indicator Lamp (MIL)=NBAT0183The MIL is located on the instrument panel.
1. The MIL will light up when the ignition switch is turned ON
without the engine running. This is a bulb check.
IIf the MIL does not light up, refer to EL-114, ªSchematicº.
(Or refer to EC-648, ªWiring Diagramº.)
2. When the engine is started, the MIL should go off.
If the MIL remains on, the on board diagnostic system has
detected an engine system malfunction. For detail, refer to
EC-59, ªIntroductionº.
CONSULT-IINBAT0184After performing ªSELF-DIAGNOSTIC PROCEDURE (WITH CON-
SULT-II)º (AT-37), place check marks for results on the ªDIAGNOS-
TIC WORKSHEETº, AT-55. Reference pages are provided follow-
ing the items.
NOTICE:
1) The CONSULT-II electrically displays shift timing and lock-up
timing (that is, operation timing of each solenoid).
Check for time difference between actual shift timing and the
CONSULT-II display. If the difference is noticeable, mechani-
cal parts (except solenoids, sensors, etc.) may be malfunction-
ing. Check mechanical parts using applicable diagnostic pro-
cedures.
2) Shift schedule (which implies gear position) displayed on
CONSULT-II and that indicated in Service Manual may differ
slightly. This occurs because of the following reasons:
IActual shift schedule has more or less tolerance or allowance,
IShift schedule indicated in Service Manual refers to the point
where shifts start, and
IGear position displayed on CONSULT-II indicates the point
where shifts are completed.
3) Shift solenoid valve ªAº or ªBº is displayed on CONSULT-II at
the start of shifting. Gear position is displayed upon completion
of shifting (which is computed by TCM).
4) Additional CONSULT-II information can be found in the Opera-
tion Manual supplied with the CONSULT-II unit.
SAT014K
SELF-DIAGNOSTIC PROCEDURE (WITH CONSULT-II)NBAT0184S011. Turn on CONSULT-II and touch ªENGINEº for OBD-II detected
items or touch ªA/Tº for TCM self-diagnosis.
If A/T is not displayed, check TCM power supply and ground
circuit. Refer to AT-92. If result is NG, refer to EL-9, ªSche-
maticº.
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ON BOARD DIAGNOSTIC SYSTEM DESCRIPTION
Malfunction Indicator Lamp (MIL)
AT-37

4. 4-3. Cruise testAT-67
AT-71
Part-1
l8. Vehicle Cannot Be Started From D
1, AT-233.
l9. A/T Does Not Shift: D
1,D2Or Does Not Kickdown: D4,D2, AT-236.
l10. A/T Does Not Shift: D
2,D3, AT-239.
l11. A/T Does Not Shift: D
3,D4, AT-242.
l12. A/T Does Not Perform Lock-up, AT-245.
l13. A/T Does Not Hold Lock-up Condition, AT-247.
l14. Lock-up Is Not Released, AT-249.
l15. Engine Speed Does Not Return To Idle (Light Braking D
4,D3), AT-250.
Part-2AT-75
l16. Vehicle Does Not Start From D
1, AT-252.
l9. A/T Does Not Shift: D
1,D2Or Does Not Kickdown: D4,D2, AT-236.
l10. A/T Does Not Shift: D
2,D3, AT-239.
l11. A/T Does Not Shift: D
3,D4, AT-242.
Part-3AT-77
l17. A/T Does Not Shift: D
4,D3When Overdrive Control Switch ªONº,ªOFFº, AT-253
l15. Engine Speed Does Not Return To Idle (Engine Brake In D
3), AT-250.
l18. A/T Does Not Shift: D
3,22, When Selector Lever ªDº,ª2º Position, AT-254.
l15. Engine Speed Does Not Return To Idle (Engine Brake In 2
2), AT-250.
l19. A/T Does Not Shift: 2
2,11, When Selector Lever ª2º,ª1º Position, AT-255.
l20. Vehicle Does Not Decelerate By Engine Brake, AT-256.
lSELF-DIAGNOSTIC PROCEDURE Ð Mark detected items.
lDTC P0705 PNP switch, AT-99.
lDTC P0710 A/T fluid temperature sensor, AT-105.
lDTC P0720 Vehicle speed sensor´A/T (Revolution sensor), AT-111.
lDTC P0725 Engine speed signal, AT-116.
lDTC P0740 Torque converter clutch solenoid valve, AT-148.
lDTC P0745 Line pressure solenoid valve, AT-162.
lDTC P0750 Shift solenoid valve A, AT-168.
lDTC P0755 Shift solenoid valve B, AT-172.
lDTC P1705 Throttle position sensor, AT-176.
lDTC P1760 Overrun clutch solenoid valve, AT-185.
lDTC BATT/FLUID TEMP SEN (A/T fluid temperature sensor and TCM power source), AT-190.
lDTC Vehicle speed sensor´MTR, AT-197.
lDTC Turbine revolution sensor, AT-202.
lDTC A/T communication line, AT-207.
lDTC Control unit (RAM), control unit (ROM), AT-211.
lDTC Control unit (EEP ROM), AT-213.
lPNP, overdrive control and throttle position switches, AT-257.
lBattery
lOthers
5.lFor self-diagnosis NG items, inspect each component. Repair or replace the damaged parts. AT-38
6.lPerform all ROAD TEST and re-mark required procedures. AT-63
7.lPerform DTC CONFIRMATION PROCEDURE for following MIL indicating items and check out NG items.
Refer to EC-60, ªEmission-related Diagnostic Informationº.EC-60
lDTC (P0731, 1103) A/T 1st gear function, AT-120.
lDTC (P0732, 1104) A/T 2nd gear function, AT-126.
lDTC (P0733, 1105) A/T 3rd gear function, AT-132.
lDTC (P0734, 1106) A/T 4th gear function, AT-138.
lDTC (P0744, 1107) A/T TCC S/V function (lock-up), AT-153.
8.lPerform the Diagnostic Procedures for all remaining items marked NG. Repair or replace the damaged
parts.
Refer to the Symptom Chart when you perform the procedures. (The chart also shows some other possible
symptoms and the component inspection orders.)AT-92
AT-97
9.lErase DTC from TCM and ECM memories. AT-35
TROUBLE DIAGNOSIS Ð INTRODUCTION
Introduction (Cont'd)
AT-56

A/T Fluid CheckNBAT0021FLUID LEAKAGE CHECKNBAT0021S011. Clean area suspected of leaking. Ð for example, mating sur-
face of converter housing and transmission case.
2. Start engine, apply foot brake, place selector lever in ªDº posi-
tion and wait a few minutes.
3. Stop engine.
4. Check for fresh leakage.
SAT638A
FLUID CONDITION CHECKNBAT0021S02
Fluid color Suspected problem
Dark or black with burned odor Wear of frictional material
Milky pinkWater contamination Ð Road water
entering through filler tube or breather
Varnished fluid, light to dark brown
and tackyOxidation Ð Over or under filling, Ð
Overheating
FLUID LEVEL CHECKNBAT0021S03Refer to MA-21, ªChecking A/T Fluidº.
SAT647B
Stall TestNBAT0022STALL TEST PROCEDURENBAT0022S011. Check A/T fluid and engine oil levels. If necessary, add fluid
and oil.
2. Drive vehicle for approx. 10 minutes or until fluid and oil reach
operating temperature.
ATF operating temperature:
50 - 80ÉC (122 - 176ÉF)
SAT513G
3. Set parking brake and block wheels.
4. Install a tachometer where it can be seen by driver during test.
IIt is good practice to put a mark on point of specified
engine rpm on indicator.
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TROUBLE DIAGNOSIS Ð BASIC INSPECTION
A/T Fluid Check
AT-59

7 CHECK LOCK-UP OFF (D4L/U TO D4)
1. Release accelerator pedal.
2. Is lock-up released when accelerator pedal is released?
SAT958I
YesorNo
Ye s©GO TO 8.
No©Go to ª14. Lock-up Is Not Releasedº, AT-249.
8 CHECK SHIFT DOWN (D4TO D3)
1. Decelerate vehicle by applying foot brake lightly.
2. Does engine speed return to idle smoothly when A/T is shifted from D
4to D3?
Read gear position and engine speed.
SAT959I
YesorNo
Ye s©1. Stop vehicle.
2. Go to ªCruise test Ð Part 2º, AT-75.
No©Go to ª15. Engine Speed Does Not Return To Idle (Light Braking D
4,D3)º, AT-250.
TROUBLE DIAGNOSIS Ð BASIC INSPECTION
Road Test (Cont'd)
AT-74

3 CHECK ENGINE BRAKE
Does vehicle decelerate by engine brake?
SAT999IA
YesorNo
Ye s©GO TO 4.
No©Go to ª15. Engine Speed Does Not Return To Idle (Light Braking D
4,D3)º, AT-250.
4 CHECK SHIFT DOWN (D3TO D2)
1. Move selector lever from ªDº to ª2º position while driving in D3(O/D OFF).
2. Does A/T shift from D
3(O/D OFF) to 22?
Read gear position.
SAT791GB
YesorNo
Ye s©GO TO 5.
No©Go to ª18. A/T Does Not Shift: D
3,D2, When Selector Lever ªDº,ª2º Positionº,
AT-254.
TROUBLE DIAGNOSIS Ð BASIC INSPECTION
Road Test (Cont'd)
AT-78

5 CHECK ENGINE BRAKE
Does vehicle decelerate by engine brake?
SAT791GB
YesorNo
Ye s©GO TO 6.
No©Go to ª15. Engine Speed Does Not Return To Idle (Light Braking D
4,D3)º, AT-250.
6 CHECK SHIFT DOWN (22TO 11)
1. Move selector lever from ª2º to ª1º position while driving in 22.
2. Does A/T shift from 2
2to 11position?
SAT778B
YesorNo
Ye s©GO TO 7.
No©Go to ª19. A/T Does Not Shift: 2
2,11, When Selector lever ª2º,ª1º Positionº, AT-255.
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TROUBLE DIAGNOSIS Ð BASIC INSPECTION
Road Test (Cont'd)
AT-79