torque INFINITI QX4 2001 Factory User Guide
Page 37 of 2395
Valve name Function
Shift valve A Simultaneously switches three oil circuits using output pressure of shift solenoid valve
A to meet driving conditions (vehicle speed, throttle opening, etc.).
Provides automatic downshifting and up-shifting (1st,2nd,3rd,4th gears/4th
,3rd,2nd,1st gears) in combination with shift valve B.
Shift valve B Simultaneously switches three oil circuits using output pressure of shift solenoid valve
B in relation to driving conditions (vehicle speed, throttle opening, etc.).
Provides automatic downshifting and up-shifting (1st,2nd,3rd,4th gears/4th
,3rd,2nd,1st gears) in combination with shift valve A.
Shuttle shift valve S Switches hydraulic circuits to provide 3-2 timing control and overrun clutch control in
relation to the throttle opening.
Inactivates the overrun clutch to prevent interlocking in 4th gear when the throttle is
wide open.
Overrun clutch control valve Switches hydraulic circuits to prevent engagement of the overrun clutch simulta-
neously with application of the brake band in 4th gear. (Interlocking occurs if the
overrun clutch engages during D
4gear operation.)
4-2 relay valve Memorizes that the transmission is in 4th gear. Prevents the transmission from down-
shifting from 4th gear to 3rd and then to 2nd in combination with 4-2 sequence valve
and shift valves A and B when downshifting from 4th to 2nd gear.
4-2 sequence valve Prevents band servo pressure from draining before high clutch operating pressure
and band servo releasing pressure drain (from the same circuit) during downshifting
from 4th to 2nd gear.
Servo charger valve An accumulator and a one-way orifice are used in the 2nd gear band servo oil circuit
to dampen shifting shock when shifting from 1st to 2nd gear.
To maintain adequate flow rate when downshifting from 4th or 3rd gear to 2nd gear,
the servo charger valve directs 2nd gear band servo hydraulic pressure to the circuit
without going through the one-way orifice when downshifting from 3rd or a higher
gear.
3-2 timing valve Prevents a late operation of the brake band when shifting selector lever from ªDº to
ª1º or ª2º position while driving in D
3.
ª1º reducing valve Reduces low & reverse brake pressure to dampen engine-brake shock when down-
shifting from the ª1º position 2nd gear to 1st gear.
Overrun clutch reducing valve Reduces oil pressure directed to the overrun clutch and prevents engine-brake shock.
In ª1º and ª2º positions, line pressure acts on the overrun clutch reducing valve to
increase the pressure-regulating point, with resultant engine brake capability.
Torque converter relief valve Prevents an excessive rise in torque converter pressure.
Torque converter clutch control valve,
torque converter clutch control plug and
torque converter clutch control sleeveActivate or inactivate the lock-up function.
Also provide smooth lock-up through transient application and release of the lock-up
system.
Shuttle shift valve D Switches hydraulic circuits so that output pressure of the torque converter clutch sole-
noid valve acts on the lock-up valve in the ªDº position of 2nd, 3rd and 4th gears. (In
the ªDº position 1st gear, lock-up is inhibited.)
ILock-up control is not affected in ªDº position 2nd, 3rd or 4th gears, unless output
pressure of the torque converter clutch solenoid valve is generated by a signal
from the control unit.
OVERALL SYSTEM
Control Valve (Cont'd)
AT-32 
Page 47 of 2395
Item DisplayMonitor item
Description Remarks
TCM input
signalsMain sig-
nals
Torque converter clutch
solenoid valve dutyTCC S/V DUTY
[%]
ÐXIControl value of torque
converter clutch solenoid
valve, computed by
TCM from each input
signal, is displayed.
Shift solenoid valve A SHIFT S/V A
[ON/OFF]
ÐXIControl value of shift
solenoid valve A, com-
puted by TCM from
each input signal, is dis-
played.Control value of solenoid is
displayed even if solenoid
circuit is disconnected.
The ªOFFº signal is dis-
played if solenoid circuit is
shorted.
Shift solenoid valve B SHIFT S/V B
[ON/OFF]
ÐXIControl value of shift
solenoid valve B, com-
puted by TCM from
each input signal, is dis-
played.
Overrun clutch solenoid
valveOVERRUN/C S/V
[ON/OFF]
ÐXIControl value of overrun
clutch solenoid valve
computed by TCM from
each input signal is dis-
played.
Self-diagnosis display lamp
(O/D OFF indicator lamp)SELF-D DP LMP
[ON/OFF] Ð XIControl status of O/D
OFF indicator lamp is
displayed.
X: Applicable
Ð: Not applicable
SAT131K
DTC WORK SUPPORT MODE WITH CONSULT-IINBAT0184S04CONSULT-II Setting ProcedureNBAT0184S04011. Turn ignition switch ªOFFº.
2. Connect CONSULT-II to data link connector, which is located
in instrument lower panel on driver side.
SAT586J
3. Turn ignition switch ªONº.
4. Touch ªSTARTº.
ON BOARD DIAGNOSTIC SYSTEM DESCRIPTION
CONSULT-II (Cont'd)
AT-42 
Page 50 of 2395
SAT596J
SAT593J
13. CONSULT-II procedure ended.
If ªNGº appears on the screen, a malfunction may exist. Go to
ªDIAGNOSTIC PROCEDUREº.
DTC WORK SUPPORT MODENBAT0184S05
DTC work support item Description Check item
1ST GR FNCTN P0731Following items for ªA/T 1st gear function (P0731)º can be con-
firmed.
ISelf-diagnosis status (whether the diagnosis is being con-
ducted or not)
ISelf-diagnosis result (OK or NG)IShift solenoid valve A
IShift solenoid valve B
IEach clutch
IHydraulic control circuit
2ND GR FNCTN P0732Following items for ªA/T 2nd gear function (P0732)º can be con-
firmed.
ISelf-diagnosis status (whether the diagnosis is being con-
ducted or not)
ISelf-diagnosis result (OK or NG)IShift solenoid valve B
IEach clutch
IHydraulic control circuit
3RD GR FNCTN P0733Following items for ªA/T 3rd gear function (P0733)º can be con-
firmed.
ISelf-diagnosis status (whether the diagnosis is being con-
ducted or not)
ISelf-diagnosis result (OK or NG)IShift solenoid valve A
IEach clutch
IHydraulic control circuit
4TH GR FNCTN P0734Following items for ªA/T 4th gear function (P0734)º can be con-
firmed.
ISelf-diagnosis status (whether the diagnosis is being con-
ducted or not)
ISelf-diagnosis result (OK or NG)IShift solenoid valve A
IShift solenoid valve B
IOverrun clutch solenoid valve
ILine pressure solenoid valve
IEach clutch
IHydraulic control circuit
TCC S/V FNCTN P0744Following items for ªA/T TCC S/V function (lock-up) (P0744)º can
be confirmed.
ISelf-diagnosis status (whether the diagnosis is being con-
ducted or not)
ISelf-diagnosis result (OK or NG)ITorque converter clutch sole-
noid valve
IEach clutch
IHydraulic control circuit
GI
MA
EM
LC
EC
FE
TF
PD
AX
SU
BR
ST
RS
BT
HA
SC
EL
IDX
ON BOARD DIAGNOSTIC SYSTEM DESCRIPTION
CONSULT-II (Cont'd)
AT-45 
Page 56 of 2395
O/D OFF indicator lamp:
6th judgement flicker is longer than others.
SAT672I
Overrun clutch solenoid valve circuit is short-circuited or discon-
nected.
ÞGo to DTC P1760 OVERRUN CLUTCH SOLENOID VALVE,
AT-185.7th judgement flicker is longer than others.
SAT673I
Torque converter clutch solenoid valve circuit is short-circuited
or disconnected.
ÞGo to DTC P0740 TORQUE CONVERTER CLUTCH SOLE-
NOID VALVE, AT-148.
8th judgement flicker is longer than others.
SAT674I
A/T fluid temperature sensor is disconnected or TCM power
source circuit is damaged.
ÞGo to DTC BATT/FLUID TEMP SEN (A/T FLUID TEM-
PERATURE SENSOR AND TCM POWER SOURCE), AT-190.9th judgement flicker is longer than others.
SAT675I
Engine speed signal circuit is short-circuited or disconnected.
ÞGo to DTC P0725 ENGINE SPEED SIGNAL, AT-116.
10th judgement flicker is longer than others.
SAT676I
Turbine revolution sensor circuit is short-circuited or discon-
nected.
ÞGo to DTC Turbine Revolution Sensor, AT-202.11th judgement flicker is longer than others.
SAT677I
Line pressure solenoid valve circuit is short-circuited or discon-
nected.
ÞGo to DTC P0745 LINE PRESSURE SOLENOID VALVE,
AT-162.
GI
MA
EM
LC
EC
FE
TF
PD
AX
SU
BR
ST
RS
BT
HA
SC
EL
IDX
ON BOARD DIAGNOSTIC SYSTEM DESCRIPTION
Diagnostic Procedure Without CONSULT-II (Cont'd)
AT-51 
Page 60 of 2395
Diagnostic Worksheet=NBAT0019S0102
1.lRead the Fail-safe Remarks and listen to customer complaints. AT-8
2.lCHECK A/T FLUIDAT-59
lLeakage (Follow specified procedure)
lFluid condition
lFluid level
3. Perform STALL TEST and LINE PRESSURE TEST. AT-59, AT-62
lStall test Ð Mark possible damaged components/others.
lTorque converter one-way clutch
lReverse clutch
lForward clutch
lOverrun clutch
lForward one-way clutchlLow & reverse brake
lLow one-way clutch
lEngine
lLine pressure is low
lClutches and brakes except high clutch and
brake band are OK
lPressure test Ð Suspected parts:
4.lPerform all ROAD TEST and mark required procedures. AT-63
4-1. Check before engine is started.AT-64
lSELF-DIAGNOSTIC PROCEDURE - 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
4-2. Check at idleAT-66
l1. O/D OFF Indicator Lamp Does Not Come On, AT-218.
l2. Engine Cannot Be Started In ªPº And ªNº Position, AT-221.
l3. In ªPº Position, Vehicle Moves Forward Or Backward When Pushed, AT-222.
l4. In ªNº Position, Vehicle Moves, AT-223.
l5. Large Shock. ªNº,ªRº Position, AT-225.
l6. Vehicle Does Not Creep Backward In ªRº Position, AT-227.
l7. Vehicle Does Not Creep Forward In ªDº, ª2º Or ª1º Position, AT-230.GI
MA
EM
LC
EC
FE
TF
PD
AX
SU
BR
ST
RS
BT
HA
SC
EL
IDX
TROUBLE DIAGNOSIS Ð INTRODUCTION
Introduction (Cont'd)
AT-55 
Page 61 of 2395
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 
Page 65 of 2395
SAT514G
5. Start engine, apply foot brake, and place selector lever in ªDº
position.
6. Accelerate to wide open throttle gradually while applying foot
brake.
7. Quickly note the engine stall revolution and immediately
release throttle.
IDuring test, never hold throttle wide open for more than 5
seconds.
Stall revolution:
Refer to SDS, AT-356.
SAT771B
8. Move selector lever to ªNº position.
9. Cool off ATF.
IRun engine at idle for at least one minute.
10. Repeat steps 5 through 9 with selector lever in ª2º, ª1º and ªRº
positions.
JUDGEMENT OF STALL TESTNBAT0022S02The test result and possible damaged components relating to each
result are shown in the illustration. In order to pinpoint the possible
damaged components, refer to ªWork Flowº, AT-57.
NOTE:
Stall revolution is too high in ªDº or ª2º position:
ISlippage occurs in 1st gear but not in 2nd and 3rd gears. .....
Low one-way clutch slippage
ISlippage occurs at the following gears:
1st through 3rd gears in ªDº position and engine brake func-
tions.
1st and 2nd gears in ª2º position and engine brake functions
with accelerator pedal released (fully closed throttle). ..... For-
ward clutch or forward one-way clutch slippage
Stall revolution is too high in ªRº position:
IEngine brake does not function in ª1º position. ..... Low &
reverse brake slippage
IEngine brake functions in ª1º position. ..... Reverse clutch slip-
page
Stall revolution within specifications:
IVehicle does not achieve speed of more than 80 km/h (50
MPH). ..... One-way clutch seizure in torque converter housing
CAUTION:
Be careful since automatic fluid temperature increases abnor-
mally.
ISlippage occurs in 3rd and 4th gears in ªDº position. ..... High
clutch slippage
ISlippage occurs in 2nd and 4th gear in ªDº position. ..... Brake
band slippage
Stall revolution less than specifications:
IPoor acceleration during starts. ..... One-way clutch seizure in
torque converter
TROUBLE DIAGNOSIS Ð BASIC INSPECTION
Stall Test (Cont'd)
AT-60 
Page 86 of 2395
Symptom ChartNBAT0233Numbers are arranged in order of inspection.
Perform inspections starting with number one and work up.
Items Symptom Condition Diagnostic Item Reference Page
No Lock-up
Engagement/TCC
InoperativeTorque converter
is not locked up.ON vehicle1. Throttle position sensor (Adjustment) EC-174
2. Vehicle speed sensor´A/T (Revolution
sensor) and vehicle speed sensor´MTRAT- 111 , 1 9 7
3. Park/neutral position (PNP) switch
adjustmentAT-276
4. Engine speed signal AT-116
5. A/T fluid temperature sensor AT-105
6. Line pressure test AT-62
7. Torque converter clutch solenoid valve AT-148
8. Control valve assembly AT-273
OFF vehicle 9. Torque converter AT-286
Torque converter
clutch piston slip.ON vehicle1. Fluid level AT-59
2. Throttle position sensor (Adjustment) EC-174
3. Line pressure test AT-62
4. Torque converter clutch solenoid valve AT-148
5. Line pressure solenoid valve AT-162
6. Control valve assembly AT-273
OFF vehicle 7. Torque converter AT-286
Lock-up point is
extremely high or
low.
AT-245ON vehicle1. Throttle position sensor (Adjustment) EC-174
2. Vehicle speed sensor´A/T (Revolution
sensor) and vehicle speed sensor´MTRAT- 111 , 1 9 7
3. Torque converter clutch solenoid valve AT-148
4. Control valve assembly AT-273
Shift ShockSharp shock in
shifting from N to
D position.ON vehicle1. Engine idling rpm EC-431
2. Throttle position sensor (Adjustment) EC-174
3. Line pressure test AT-62
4. A/T fluid temperature sensor AT-105
5. Engine speed signal AT-116
6. Line pressure solenoid valve AT-162
7. Control valve assembly AT-273
8. Accumulator N-D AT-273
OFF vehicle9. Turbine revolution sensor EC-368
10. Forward clutch AT-320
GI
MA
EM
LC
EC
FE
TF
PD
AX
SU
BR
ST
RS
BT
HA
SC
EL
IDX
TROUBLE DIAGNOSIS Ð GENERAL DESCRIPTION
Symptom Chart
AT-81 
Page 91 of 2395
Items Symptom Condition Diagnostic Item Reference Page
Slips/Will Not
EngageVehicle will not
run in D, 1, 2
positions (but
runs in R posi-
tion). Clutch slips.
Very poor accel-
eration.
AT-230ON vehicle1. Fluid level AT-59
2. Line pressure test AT-62
3. Line pressure solenoid valve AT-162
4. Control valve assembly AT-273
5. Accumulator N-D AT-273
OFF vehicle6. Reverse clutch AT-314
7. High clutch AT-317
8. Forward clutch AT-320
9. Forward one-way clutch AT-330
10. Low one-way clutch AT-328
Clutches or
brakes slip some-
what in starting.ON vehicle1. Fluid level AT-59
2. Manual control linkage adjustment AT-276
3. Throttle position sensor (Adjustment) EC-174
4. Line pressure test AT-62
5. Line pressure solenoid valve AT-162
6. Control valve assembly AT-273
7. Accumulator N-D AT-273
OFF vehicle8. Forward clutch AT-320
9. Reverse clutch AT-314
10. Low & reverse brake AT-324
11. Oil pump AT-297
12. Torque converter AT-286
No creep at all.
AT-227, 230ON vehicle1. Fluid level AT-59
2. Line pressure test AT-62
3. Control valve assembly AT-273
OFF vehicle4. Forward clutch AT-320
5. Oil pump AT-297
6. Torque converter AT-286
Almost no shock
or clutches slip-
ping in change
from D
1to D2.ON vehicle1. Fluid level AT-59
2. Throttle position sensor (Adjustment) EC-174
3. Line pressure test AT-62
4. Accumulator servo release AT-273
5. Control valve assembly AT-273
OFF vehicle 6. Brake band AT-333
TROUBLE DIAGNOSIS Ð GENERAL DESCRIPTION
Symptom Chart (Cont'd)
AT-86 
Page 93 of 2395
Items Symptom Condition Diagnostic Item Reference Page
Slips/Will Not
EngageRaces extremely
fast or slips in
changing from D
4or D3to D1when
depressing pedal.ON vehicle1. Fluid level AT-59
2. Throttle position sensor (Adjustment) EC-174
3. Line pressure test AT-62
4. Line pressure solenoid valve AT-162
5. Control valve assembly AT-273
OFF vehicle6. Forward clutch AT-320
7. Forward one-way clutch AT-330
8. Low one-way clutch AT-328
Vehicle will not
run in any posi-
tion.ON vehicle1. Fluid level AT-59
2. Manual control linkage adjustment AT-276
3. Line pressure test AT-62
4. Line pressure solenoid valve AT-162
OFF vehicle5. Oil pump AT-297
6. High clutch AT-317
7. Brake band AT-333
8. Low & reverse brake AT-324
9. Torque converter AT-286
10. Parking pawl components AT-337
NOT USEDEngine cannot be
started in P and N
positions.
AT-221ON vehicle1. Ignition switch and starter EL-9, and SC-10
2. Manual control linkage adjustment AT-276
3. Park/neutral position (PNP) switch
adjustmentAT-276
Engine starts in
positions other
than P and N.
AT-221ON vehicle1. Manual control linkage adjustment AT-276
2. Park/neutral position (PNP) switch
adjustmentAT-276
Transmission
noise in P and N
positions.ON vehicle1. Fluid level AT-59
2. Line pressure test AT-62
3. Throttle position sensor (Adjustment) EC-174
4. Vehicle speed sensor´A/T (Revolution
sensor) and vehicle speed sensor´MTRAT- 111 , 1 9 7
5. Engine speed signal AT-116
OFF vehicle6. Oil pump AT-297
7. Torque converter AT-286
Vehicle moves
when changing
into P position or
parking gear does
not disengage
when shifted out
of P position.
AT-222ON vehicle 1. Manual control linkage adjustment AT-276
OFF vehicle 2. Parking pawl components AT-337
TROUBLE DIAGNOSIS Ð GENERAL DESCRIPTION
Symptom Chart (Cont'd)
AT-88