2001 INFINITI QX4 torque

Diagnostic ProcedureNBAT0052
1 CHECK VALVE RESISTANCE
1. Turn ignition switch to ªOFFº position.
2. Disconnect terminal cord assembly connector on the right side of transfer assembly.
3. Check resistance between terminal 7 and ground.
SAT156J
Is resistance approx. 10 - 20W?
Ye s©GO TO 3.
No©GO TO 2.
2 CHECK VALVE OPERATION
1. Remove oil pan. Refer to AT-273.
2. Check the following items:
ITorque converter clutch solenoid valve
Refer to ªComponent Inspectionº, AT-152.
IHarness of terminal cord assembly for short or open
OK or NG
OK©GO TO 3.
NG©Repair open circuit or short to ground or short to power in harness or connectors.
3 CHECK RESISTANCE
1. Turn ignition switch to ªOFFº position.
2. Disconnect TCM harness connector.
3. Check resistance between terminal 7 and TCM harness connector terminal 3. Refer to wiring diagram Ð AT Ð TCV.
Continuity should exist.
If OK, check harness for short to ground and short to power.
4. Reinstall any part removed.
OK or NG
OK©GO TO 4.
NG©Repair open circuit or short to ground or short to power in harness or connectors.
4 CHECK DTC
Perform Diagnostic Trouble Code (DTC) confirmation procedure, AT-149.
OK or NG
OK©INSPECTION END
NG©GO TO 5.
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DTC P0740 TORQUE CONVERTER CLUTCH SOLENOID VALVE
Diagnostic Procedure
AT-151

5 CHECK TCM INSPECTION
1. Perform TCM input/output signal inspection.
2. If NG, recheck TCM pin terminals for damage or loose connection with harness connector.
OK or NG
OK©INSPECTION END
NG©Repair or replace damaged parts.
SAT160J
Component InspectionNBAT0053TORQUE CONVERTER CLUTCH SOLENOID VALVENBAT0053S01IFor removal, refer to AT-273.
Resistance CheckNBAT0053S0101ICheck resistance between terminal 7 and ground.
Solenoid valve Terminal No. Resistance (Approx.)
Torque converter clutch
solenoid valve7 Ground 10 - 20W
SAT161J
Operation CheckNBAT0053S0102ICheck solenoid valve by listening for its operating sound while
applying battery voltage to the terminal 7 and ground.
DTC P0740 TORQUE CONVERTER CLUTCH SOLENOID VALVE
Diagnostic Procedure (Cont'd)
AT-152

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.
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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

7 CHECK CONTROL VALVE
1. Disassemble control valve assembly. Refer to AT-301.
2. Check line pressure circuit valves for sticking.
IPressure regulator valve
IPilot valve
IPressure modifier valve
SAT367H
OK or NG
OK©GO TO 8.
NG©Repair control valve.
8 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.
9 CHECK DTC
Perform Diagnostic Trouble Code (DTC) confirmation procedure, AT-154.
OK or NG
OK©INSPECTION END
NG©IGO TO 10.
IAnd check for proper lock-up.
10 CHECK LOCK-UP CONDITION
During ªCruise test þ Part 1º, AT-71.
Does A/T perform lock-up at the specified speed?
YesorNo
Ye s©Perform ªCruise test þ Part 1º again and return to the start point of this flow chart.
No©GO TO 11.
11 CHECK TORQUE CONVERTER CLUTCH SOLENOID VALVE
1. Remove control valve assembly. Refer to AT-273.
2. Check torque converter clutch solenoid valve operation.
Refer to AT-161.
OK or NG
OK©GO TO 12.
NG©Replace solenoid valve assembly.
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DTC P0744 IMPROPER LOCK-UP OPERATION
Diagnostic Procedure (Cont'd)
AT-159

12 CHECK CONTROL VALVE
1. Disassemble control valve assembly. Refer to AT-301.
2. Check control valves for sticking.
ITorque converter clutch control valve
ITorque converter clutch relief valve
SAT367H
OK or NG
OK©GO TO 13.
NG©Repair control valve
13 CHECK LOCK-UP CONDITION
Does A/T perform lock-up at the specified speed?
YesorNo
Ye s©GO TO 14.
No©Check control valve again. Repair or replace control valve assembly.
14 CHECK DTC
Perform Diagnostic Trouble Code (DTC) confirmation procedure, AT-154.
OK or NG
OK©INSPECTION END
NG©Perform ªCruise test Ð Part 1º again and return to the start point of this flow chart.
DTC P0744 IMPROPER LOCK-UP OPERATION
Diagnostic Procedure (Cont'd)
AT-160

SAT159J
Component InspectionNBAT0056SOLENOID VALVESNBAT0056S01IFor removal, refer to AT-273.
Resistance CheckNBAT0056S0101ICheck resistance between terminals (6 or 7) and ground.
Solenoid valve Terminal No. Resistance (Approx.)
Line pressure solenoid valve 6
Ground2.5-5W
Torque converter clutch
solenoid valve7 10-20W
SAT158J
Operation CheckNBAT0056S0102ICheck solenoid valve by listening for its operating sound while
applying battery voltage to the terminals (6 or 7) and ground.
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DTC P0744 IMPROPER LOCK-UP OPERATION
Component Inspection
AT-161

6. Vehicle Does Not Creep Backward In ªRº
Position
=NBAT0078SYMPTOM:
Vehicle does not creep backward when selecting ªRº position.
1 CHECK A/T FLUID LEVEL
Check A/T fluid level again.
SAT638A
OK or NG
OK©GO TO 2.
NG©Refill ATF.
2 CHECK STALL TEST
Check stall revolution with selector lever in ª1º and ªRº positions.
Refer to AT-356.
SAT493G
OK or NG
OK©GO TO 3.
OK in ª1º position, NG in
ªRº position©1. Remove control valve assembly. Refer to ªON-VEHICLE SERVICEº, AT-273.
2. Check the following items:
IValves to control line pressure (Pressure regulator valve, pressure modifier valve, pilot
valve and pilot filter)
ILine pressure solenoid valve
3. Disassemble A/T.
4. Check the following items:
IOil pump assembly
ITorque converter
IReverse clutch assembly
IHigh clutch assembly
NG in both ª1º and ªRº
positions©GO TO 6.
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TROUBLE DIAGNOSES FOR SYMPTOMS
6. Vehicle Does Not Creep Backward In ªRº Position
AT-227