2001 INFINITI QX4 elec

ON BOARD DIAGNOSIS LOGIC=NBAT0048S03This diagnosis monitors actual gear position by checking the torque
converter slip ratio calculated by TCM as follows:
Torque converter slip ratio = A x C/B
A: Output shaft revolution signal from revolution sensor
B: Engine speed signal from ECM
C: Gear ratio determined as gear position which TCM supposes
If the actual gear position is much lower than the position (4th)
supposed by TCM, the slip ratio will be much less than normal. In
case the ratio does not reach the specified value, TCM judges this
diagnosis malfunction.
This malfunction will be caused when shift solenoid valve B is stuck
closed.
Gear position supposed by TCM1234
In case of gear position with no malfunctions1234
In case of gear position with shift solenoid valve B
stuck closed1221*
*: P0734 is detected.
Diagnostic trouble code Malfunction is detected when ... Check item (Possible cause)
: A/T 4TH GR FNCTN
A/T cannot be shifted to the 4th gear
position even if electrical circuit is good.IShift solenoid valve A
IShift solenoid valve B
ILine pressure solenoid valve
IEach clutch
IHydraulic control circuit
: P0734
GI
MA
EM
LC
EC
FE
TF
PD
AX
SU
BR
ST
RS
BT
HA
SC
EL
IDX
DTC P0734 IMPROPER SHIFTING TO 4TH GEAR POSITION
Description (Cont'd)
AT-139

SAT014K
SAT971J
SAT021J
DIAGNOSTIC TROUBLE CODE (DTC) CONFIRMATION
PROCEDURE
NBAT0048S01CAUTION:
IAlways drive vehicle at a safe speed.
IBe careful not to rev engine into the red zone on the
tachometer.
NOTE:
If ªDIAGNOSTIC TROUBLE CODE CONFIRMATION PROCE-
DUREº has been previously conducted, always turn ignition
switch ªOFFº and wait at least 5 seconds before conducting
the next test.
TESTING CONDITIONS:
Always drive vehicle on a level road to improve the accuracy
of test.
After the repair, perform the following procedure to confirm the
malfunction is eliminated.
With CONSULT-II
1) Start engine and select ªDATA MONITORº mode for ªA/Tº with
CONSULT-II.
2) Make sure that output voltage of A/T fluid temperature sensor
is within the range below.
FLUID TEMP SEN: 0.4 - 1.5V
If out of range, drive the vehicle to decrease the voltage (warm
up the fluid) or stop engine to increase the voltage (cool down
the fluid).
3) Select ª4TH GR FNCTN P0734º of ªDTC WORK SUPPORTº
mode for ªA/Tº with CONSULT-II and touch ªSTARTº.
4) Accelerate vehicle to 55 to 65 km/h (34 to 40 MPH) under the
following condition and release the accelerator pedal com-
pletely.
THROTTLE POSI: Less than 5.5/8 (at all times during step
4)
Selector lever: D position (OD ªONº)
ICheck that ªGEARº shows ª3º after releasing pedal.
5) Depress accelerator pedal steadily with 1.0/8 - 2.0/8 of
ªTHROTTLE POSIº from a speed of 55 to 65 km/h (34 to 40
MPH) until ªTESTINGº has turned to ªSTOP VEHICLEº or
ªCOMPLETEDº. (It will take approximately 3 seconds.)
If the check result NG appears on CONSULT-II screen, go to
ªDIAGNOSTIC PROCEDUREº, AT-143.
If ªSTOP VEHICLEº appears on CONSULT-II screen, go to
following step.
ICheck that ªGEARº shows ª4º when depressing accelera-
tor pedal with 1.0/8 - 2.0/8 of ªTHROTTLE POSIº.
IIf ªTESTINGº does not appear on CONSULT-II for a long
time, select ªSELF-DIAG RESULTSº for ªENGINEº. In case
a 1st trip DTC other than P0734 is shown, refer to appli-
cable ªTROUBLE DIAGNOSIS FOR DTCº.
6) Stop vehicle.
7) Follow the instruction displayed. (Check for normal shifting
referring to the table below.)
Vehicle conditionGear on actual transmission shift pattern when
screen is changed to 1,2,3,4
No malfunction exists 1,2,3,4
Malfunction for P0734 exists. 1,2,2,1
DTC P0734 IMPROPER SHIFTING TO 4TH GEAR POSITION
Description (Cont'd)
AT-140

SAT014K
SAT020K
DIAGNOSTIC TROUBLE CODE (DTC) CONFIRMATION
PROCEDURE
NBAT0051S01NOTE:
If ªDIAGNOSTIC TROUBLE CODE CONFIRMATION PROCE-
DUREº has been previously conducted, always turn ignition
switch ªOFFº and wait at least 5 seconds before conducting
the next test.
After the repair, perform the following procedure to confirm the
malfunction is eliminated.
With CONSULT-II
1) Turn ignition switch ªONº.
2) Select ªDATA MONITORº mode for ªENGINEº with CON-
SULT-II and wait at least 1 second.
With GST
Follow the procedure ªWith CONSULT-IIº.
GI
MA
EM
LC
EC
FE
TF
PD
AX
SU
BR
ST
RS
BT
HA
SC
EL
IDX
DTC P0740 TORQUE CONVERTER CLUTCH SOLENOID VALVE
Description (Cont'd)
AT-149

DescriptionNBAT0054IThis is an OBD-II self-diagnostic item and not available in TCM
self-diagnosis.
IThis malfunction will not be detected while the O/D OFF indi-
cator lamp is indicating another self-diagnosis malfunction.
IThis malfunction is detected when the A/T does not shift into
fourth gear position or the torque converter clutch does not
lock up as instructed by the TCM. This is not caused by elec-
trical malfunction (circuits open or shorted) but by mechanical
malfunction such as control valve sticking, improper solenoid
valve operation, malfunctioning oil pump or torque converter
clutch, etc.
CONSULT-II REFERENCE VALUE IN DATA MONITOR
MODE
NBAT0054S02Remarks: Specification data are reference values.
Monitor item Condition Specification
Torque converter clutch
solenoid valve dutyLock-up ªOFFº
"
Lock-up ªONºApproximately 4%
"
Approximately 94%
Line pressure solenoid
valve dutySmall throttle opening (Low line pressure)
"
Large throttle opening (High line pressure)Approximately 24%
"
Approximately 95%
TCM TERMINALS AND REFERENCE VALUENBAT0054S03Remarks: Specification data are reference values.
Terminal
No.Wire color Item ConditionJudgement
standard
(Approx.)
1GYLine pressure
solenoid valve
When releasing accelerator pedal after warm-
ing up engine.1.5 - 3.0V
When depressing accelerator pedal fully after
warming up engine.0V
2 BR/YLine pressure
solenoid valve
(with dropping
resistor)When releasing accelerator pedal after warm-
ing up engine.5 - 14V
When depressing accelerator pedal fully after
warming up engine.0V
3 G/ORTorque converter
clutch solenoid
valve
When A/T performs lock-up. 8 - 15V
When A/T does not perform lock- up. 0V
ON BOARD DIAGNOSIS LOGICNBAT0054S04This diagnosis monitors actual gear position by checking the torque
converter slip ratio calculated by TCM as follows:
Torque converter slip ratio = A x C/B
A: Output shaft revolution signal from revolution sensor
B: Engine speed signal from ECM
C: Gear ratio determined as gear position which TCM supposes
If the actual gear position is much lower than the position (4th)
supposed by TCM, the slip ratio will be much less than normal. In
case the ratio does not reach the specified value, TCM judges this
diagnosis malfunction.
This malfunction will be caused when shift solenoid valve B is stuck
closed.
GI
MA
EM
LC
EC
FE
TF
PD
AX
SU
BR
ST
RS
BT
HA
SC
EL
IDX
DTC P0744 IMPROPER LOCK-UP OPERATION
Description
AT-153

Gear position supposed by TCM 1 2 3 4
In case of gear position with no malfunctions 1 2 3 4
In case of gear position with shift solenoid valve B stuck closed 1 2 2 1*
*: P0744 is detected.
Diagnostic trouble code Malfunction is detected when ... Check item (Possible cause)
: A/T TCC S/V FNCTN
A/T cannot perform lock-up even if elec-
trical circuit is good.ILine pressure solenoid valve
ITorque converter clutch solenoid valve
IEach clutch
IHydraulic control circuit
: P0744
SAT014K
SAT971J
DIAGNOSTIC TROUBLE CODE (DTC) CONFIRMATION
PROCEDURE
NBAT0054S01CAUTION:
Always drive vehicle at a safe speed.
NOTE:
If ªDIAGNOSTIC TROUBLE CODE CONFIRMATION PROCE-
DUREº has been previously conducted, always turn ignition
switch ªOFFº and wait at least 5 seconds before conducting
the next test.
After the repair, perform the following procedure to confirm the
malfunction is eliminated.
With CONSULT-II
1) Start engine and select ªDATA MONITORº mode for ªA/Tº with
CONSULT-II.
2) Make sure that output voltage of A/T fluid temperature sensor
is within the range below.
FLUID TEMP SEN: 0.4 - 1.5V
If out of range, drive the vehicle to decrease the voltage (warm
up the fluid) or stop engine to increase the voltage (cool down
the fluid).
3) Select ªTCC S/V FNCTN P0744º of ªDTC WORK SUPPORTº
mode for ªA/Tº with CONSULT-II and touch ªSTARTº.
SAT021J
4) Accelerate vehicle to more than 67 to 100 km/h (42 to 62 MPH)
and maintain the following condition continuously until ªTEST-
INGº has turned to ªCOMPLETEDº. (It will take approximately
30 seconds after ªTESTINGº shows.)
THROTTLE POSI: 1.0/8 - 2.0/8 (at all times during step 4)
Selector lever: D position (OD ªONº)
TCC S/V DUTY: More than 94%
VHCL/S SE´A/T: Constant speed of more than 67 to 100
km/h (42 to 62 MPH)
ICheck that ªGEARº shows ª4º.
IFor shift schedule, refer to SDS, AT-356.
DTC P0744 IMPROPER LOCK-UP OPERATION
Description (Cont'd)
AT-154

IIf ªTESTINGº does not appear on CONSULT-II for a long
time, select ªSELF-DIAG RESULTSº. In case a 1st trip DTC
other than P0744 is shown, refer to applicable ªTROUBLE
DIAGNOSIS FOR DTCº.
5) Make sure that ªOKº is displayed. (If ªNGº is displayed, refer
to ªDIAGNOSTIC PROCEDUREº.)
Refer to ªDIAGNOSTIC PROCEDUREº, AT-157.
Refer to shift schedule, AT-356.
With GST
Follow the procedure ªWith CONSULT-IIº.
GI
MA
EM
LC
EC
FE
TF
PD
AX
SU
BR
ST
RS
BT
HA
SC
EL
IDX
DTC P0744 IMPROPER LOCK-UP OPERATION
Description (Cont'd)
AT-155

SAT014K
SAT020K
DIAGNOSTIC TROUBLE CODE (DTC) CONFIRMATION
PROCEDURE
NBAT0057S01NOTE:
If ªDIAGNOSTIC TROUBLE CODE CONFIRMATION PROCE-
DUREº has been previously conducted, always turn ignition
switch ªOFFº and wait at least 5 seconds before conducting
the next test.
After the repair, perform the following procedure to confirm the
malfunction is eliminated.
With CONSULT-II
1) Turn ignition switch ªONº and select ªDATA MONITORº mode
for ªENGINEº with CONSULT-II.
2) Depress accelerator pedal completely and wait at least 1 sec-
ond.
With GST
Follow the procedure ªWith CONSULT-IIº.
GI
MA
EM
LC
EC
FE
TF
PD
AX
SU
BR
ST
RS
BT
HA
SC
EL
IDX
DTC P0745 LINE PRESSURE SOLENOID VALVE
Description (Cont'd)
AT-163

SAT341H
DescriptionNBAT0060Shift solenoid valves A and B are turned ªONº or ªOFFº by the TCM
in response to signals sent from the PNP switch, vehicle speed and
throttle position sensors. Gears will then be shifted to the optimum
position.
Gear position1234
Shift solenoid valve A ON (Closed) OFF (Open) OFF (Open) ON (Closed)
Shift solenoid valve B ON (Closed) ON (Closed) OFF (Open) OFF (Open)
TCM TERMINALS AND REFERENCE VALUENBAT0060S02Remarks: Specification data are reference values.
Terminal
No.Wire color Item ConditionJudgement
standard
(Approx.)
11 L/WShift solenoid
valve A
When shift solenoid valve A operates.
(When driving in ªD
1ºorªD4º.)Battery volt-
age
When shift solenoid valve A does not operate.
(When driving in ªD
2ºorªD3º.)0V
ON BOARD DIAGNOSIS LOGICNBAT0060S03
Diagnostic trouble code Malfunction is detected when ... Check item (Possible cause)
: SFT SOL A/CIRC TCM detects an improper voltage drop
when it tires to operate the solenoid
valve.IHarness or connectors
(The solenoid circuit is open or shorted.)
IShift solenoid valve A
: P0750
SAT014K
SAT020K
DIAGNOSTIC TROUBLE CODE (DTC) CONFIRMATION
PROCEDURE
NBAT0060S01CAUTION:
Always drive vehicle at a safe speed.
NOTE:
If ªDIAGNOSTIC TROUBLE CODE CONFIRMATION PROCE-
DUREº has been previously conducted, always turn ignition
switch ªOFFº and wait at least 5 seconds before conducting
the next test.
After the repair, perform the following procedure to confirm the
malfunction is eliminated.
With CONSULT-II
1) Turn ignition switch ªONº and select ªDATA MONITORº mode
for ªENGINEº with CONSULT-II.
2) Start engine.
3) Drive vehicle in ªDº position and allow the transmission to shift
ª1º,ª2º (ªGEARº).
With GST
Follow the procedure ªWith CONSULT-IIº.
DTC P0750 SHIFT SOLENOID VALVE A
Description
AT-168