INFINITI QX4 2001 Factory Service Manual

Diagnostic ProcedureNBAT0046
1 CHECK SHIFT SOLENOID VALVE
1. Remove control valve assembly. Refer to AT-273.
2. Check shift solenoid valve operation.
IShift solenoid valve A
Refer to ªComponent Inspectionº, AT-137.
SAT653I
OK or NG
OK©GO TO 2.
NG©Repair or replace shift solenoid valve assembly.
2 CHECK CONTROL VALVE
1. Disassemble control valve assembly.
Refer to ªControl Valve Assemblyº, AT-301.
2. Check to ensure that:
IValve, sleeve and plug slide along valve bore under their own weight.
IValve, sleeve and plug are free from burrs, dents and scratches.
IControl valve springs are free from damage, deformation and fatigue.
IHydraulic line is free from obstacles.
SAT367H
OK or NG
OK©GO TO 3.
NG©Repair control valve assembly.
3 CHECK DTC
Perform Diagnostic Trouble Code (DTC) confirmation procedure, AT-133.
OK or NG
OK©INSPECTION END
NG©Check control valve again. Repair or replace control valve assembly.
DTC P0733 IMPROPER SHIFTING TO 3RD GEAR POSITION
Diagnostic Procedure
AT-136

SAT654I
Component InspectionNBAT0047SHIFT SOLENOID VALVE ANBAT0047S01IFor removal, refer to AT-273.
Resistance CheckNBAT0047S0101ICheck resistance between terminal 3 and ground.
Solenoid valve Terminal No. Resistance (Approx.)
Shift solenoid valve A 3 Ground 20 - 40W
SAT653I
Operation CheckNBAT0047S0102ICheck solenoid valve by listening for its operating sound while
applying battery voltage to the terminal 3 and ground.
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PD
AX
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DTC P0733 IMPROPER SHIFTING TO 3RD GEAR POSITION
Component Inspection
AT-137

DescriptionNBAT0048IThis 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
NBAT0048S04Remarks: Specification data are reference values.
Monitor item Condition Specification
Line pressure solenoid valve
dutySmall throttle opening (Low line pressure)
"
Large throttle opening (High line pressure)Approximately 24%
"
Approximately 95%
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 VALUENBAT0048S02Remarks: 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
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
12 L/RShift solenoid
valve BWhen shift solenoid valve B operates.
(When driving in ªD
1ºorªD2º.)Battery volt-
age
When shift solenoid valve B does not operate.
(When driving in ªD
3ºorªD4º.)0V
DTC P0734 IMPROPER SHIFTING TO 4TH GEAR POSITION
Description
AT-138

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
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LC
EC
FE
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PD
AX
SU
BR
ST
RS
BT
HA
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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

8) Make sure that ªOKº is displayed. (If ªNGº is displayed, refer
to ªDIAGNOSTIC PROCEDUREº.) Refer to ªDIAGNOSTIC
PROCEDUREº, AT-143.
Refer to shift schedule, AT-356.
With GST
Follow the procedure ªWith CONSULT-IIº.
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DTC P0734 IMPROPER SHIFTING TO 4TH GEAR POSITION
Description (Cont'd)
AT-141

Wiring Diagram Ð AT Ð 4THNBAT0193
MAT912A
DTC P0734 IMPROPER SHIFTING TO 4TH GEAR POSITION
Wiring Diagram Ð AT Ð 4TH
AT-142

Diagnostic ProcedureNBAT0049
1 CHECK SHIFT UP (D3TO D4)
During ªCruise test þ Part 1º, AT-71.
Does A/T shift from D
3to D4at the specified speed?
SAT988H
YesorNo
Ye s©GO TO 9.
No©GO TO 2.
2 CHECK LINE PRESSURE
Perform line pressure test. Refer to AT-62.
OK or NG
OK©GO TO 3.
NG©GO TO 6.
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DTC P0734 IMPROPER SHIFTING TO 4TH GEAR POSITION
Diagnostic Procedure
AT-143

3 CHECK SOLENOID VALVES
1. Remove control valve assembly. Refer to AT-273.
2. Refer to ªComponent Inspectionº, AT-147.
SAT158J
OK or NG
OK©GO TO 4.
NG©Replace solenoid valve assembly.
4 CHECK CONTROL VALVE
1. Disassemble control valve assembly. Refer to AT-301.
2. Check to ensure that:
IValve, sleeve and plug slide along valve bore under their own weight.
IValve, sleeve and plug are free from burrs, dents and scratches.
IControl valve springs are free from damage, deformation and fatigue.
IHydraulic line is free from obstacles.
SAT367H
OK or NG
OK©GO TO 5.
NG©Repair control valve.
DTC P0734 IMPROPER SHIFTING TO 4TH GEAR POSITION
Diagnostic Procedure (Cont'd)
AT-144

5 CHECK SHIFT UP (D3TO D4)
Does A/T shift from D3to D4at the specified speed?
YesorNo
Ye s©GO TO 9.
No©Check control valve again. Repair or replace control valve assembly.
6 CHECK LINE PRESSURE SOLENOID VALVE
1. Remove control valve assembly. Refer to AT-273.
2. Refer to ªComponent Inspectionº, AT-147.
SAT158J
OK or NG
OK©GO TO 7.
NG©Replace solenoid valve assembly.
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
Diagnostic Procedure (Cont'd)
AT-145