2001 INFINITI QX4 lock

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

7 CHECK TCM POWER SOURCE STEP 1
1. Turn ignition switch to ON position.
(Do not start engine.)
2. Check voltage between TCM terminals 10, 19, 28 and ground.
SAT611J
OK or NG
OK©GO TO 8.
NG©GO TO 9.
8 CHECK TCM POWER SOURCE STEP 2
1. Turn ignition switch to OFF position.
2. Check voltage between TCM terminal 28 and ground.
SAT612JC
OK or NG
OK©GO TO 10.
NG©GO TO 9.
9 DETECT MALFUNCTIONING ITEM
Check the following items:
IHarness for short or open between ignition switch and TCM terminals 10, 19 and 28 (Main harness)
IIgnition switch and 10A or 7.5A fuse [No. 18 or 24, located in the fuse block (J/B)]
Refer to EL-9, ªSchematicº.
OK or NG
OK©GO TO 10.
NG©Repair or replace damaged parts.
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DTC BATT/FLUID TEMP SEN (A/T FLUID TEMP SENSOR CIRCUIT AND TCM
POWER SOURCE)
Diagnostic Procedure (Cont'd)
AT-195

1. O/D OFF Indicator Lamp Does Not Come OnNBAT0073SYMPTOM:
O/D OFF indicator lamp does not come on for about 2 seconds
when turning ignition switch to ªONº.
1 CHECK TCM POWER SOURCE STEP 1
1. Turn ignition switch to ON position.
(Do not start engine.)
2. Check voltage between TCM terminals 10, 19, 28 and ground.
SAT611J
OK or NG
OK©GO TO 2.
NG©GO TO 3.
2 CHECK TCM POWER SOURCE STEP 2
1. Turn ignition switch to OFF position.
2. Check voltage between TCM terminal 28 and ground.
SAT612JC
OK or NG
OK©GO TO 4.
NG©GO TO 3.
3 DETECT MALFUNCTIONING ITEM
Check the following items:
IHarness for short or open between ignition switch and TCM terminals 10, 19 and 28 (Main harness)
IIgnition switch and 10A or 7.5A fuse [No. 18 or 24, located in the fuse block (J/B)]
Refer to EL-9, ªSchematicº.
OK or NG
OK©GO TO 4.
NG©Repair or replace damaged parts.
TROUBLE DIAGNOSES FOR SYMPTOMS
1. O/D OFF Indicator Lamp Does Not Come On
AT-218

12. A/T Does Not Perform Lock-up=NBAT0084SYMPTOM:
A/T does not perform lock-up at the specified speed.
1 CHECK SELF-DIAGNOSTIC RESULTS
Does self-diagnosis show damage to torque converter clutch solenoid valve circuit after cruise test?
SAT581I
YesorNo
Ye s©Check torque converter clutch solenoid valve circuit. Refer to ªDTC P0740º, AT-148.
No©GO TO 2.
2 CHECK THROTTLE POSITION SENSOR
Check throttle position sensor. Refer to EC-174, ªDescriptionº.
SAT142K
OK or NG
OK©GO TO 3.
NG©Repair or replace throttle position sensor.
3 DETECT MALFUNCTIONING ITEM
1. Remove control valve. Refer to AT-273.
2. Check following items:
ITorque converter clutch control valve
ITorque converter relief valve
ITorque converter clutch solenoid valve
IPilot valve
IPilot filter
OK or NG
OK©GO TO 4.
NG©Repair or replace damaged parts.
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TROUBLE DIAGNOSES FOR SYMPTOMS
12. A/T Does Not Perform Lock-up
AT-245

4 CHECK SYMPTOM
Check again.
OK or NG
OK©INSPECTION END
NG©1. Perform TCM input/output signal inspection.
2. If NG, recheck TCM pin terminals for damage or loose connection with harness con-
nector.
TROUBLE DIAGNOSES FOR SYMPTOMS
12. A/T Does Not Perform Lock-up (Cont'd)
AT-246

13. A/T Does Not Hold Lock-up Condition=NBAT0085SYMPTOM:
A/T does not hold lock-up condition for more than 30 seconds.
1 CHECK DIAGNOSTIC RESULTS
Does self-diagnosis show damage to engine speed signal circuit after cruise test?
SAT582I
YesorNo
Ye s©Check engine speed signal circuit. Refer to ªDTC P0725º, AT-116.
No©GO TO 2.
2 CHECK A/T FLUID CONDITION
1. Remove oil pan.
2. Check A/T fluid condition.
SAT171B
OK or NG
OK©GO TO 3.
NG©GO TO 5.
3 DETECT MALFUNCTIONING ITEM
1. Remove control valve assembly. Refer to AT-273.
2. Check the following items:
ITorque converter clutch control valve
IPilot valve
IPilot filter
OK or NG
OK©GO TO 4.
NG©Repair or replace damaged parts.
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TROUBLE DIAGNOSES FOR SYMPTOMS
13. A/T Does Not Hold Lock-up Condition
AT-247