2001 INFINITI QX4 cruise control

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?
OK or NG
OK©GO TO 9.
NG©Check control valve again. Repair or replace control valve assembly.
9 CHECK DTC
Perform Diagnostic Trouble Code (DTC) confirmation procedure, AT-140.
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 P0734 IMPROPER SHIFTING TO 4TH GEAR POSITION
Diagnostic Procedure (Cont'd)
AT-146

Diagnostic Procedure=NBAT0055
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©IGO TO 10.
IAnd check for proper lock-up.
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.
3 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 4.
NG©Repair control valve.
GI
MA
EM
LC
EC
FE
TF
PD
AX
SU
BR
ST
RS
BT
HA
SC
EL
IDX
DTC P0744 IMPROPER LOCK-UP OPERATION
Diagnostic Procedure
AT-157

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.
GI
MA
EM
LC
EC
FE
TF
PD
AX
SU
BR
ST
RS
BT
HA
SC
EL
IDX
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

11. A/T Does Not Shift: D3®D4=NBAT0083SYMPTOM:
IA/T does not shift from D
3to D4at the specified speed.
IA/T must be warm before D
3to D4shift will occur.
1 CHECK SYMPTOM
Are ª7. Vehicle Does Not Creep Forward In ªDº, ª2º Or ª1º Positionº and ª8. Vehicle Cannot Be Started From D1º OK?
YesorNo
Ye s©GO TO 2.
No©Go to ª7. Vehicle Does Not Creep Forward In ªDº, ª2º Or ª1º Positionº and ª8. Vehicle
Cannot Be Started From D
1º, AT-230, 233.
2 CHECK SELF-DIAGNOSTIC RESULTS
With CONSULT-II
Does self-diagnosis, after cruise test, show damage to any of the following circuits?
IInhibitor switch
IOverdrive control switch
IA/T fluid temperature sensor
IRevolution sensor
IShift solenoid valve A or B
IVehicle speed sensor
SAT580I
YesorNo
Ye s©Check damaged circuit. Refer to ªDTC P0705, P0710, P0720, P0750, P0755 or VHCL
SPEED SEN´MTRº, AT-99, 105, 111, 168, 172 or 197.
No©GO TO 3.
TROUBLE DIAGNOSES FOR SYMPTOMS
11. A/T Does Not Shift: D3®D4
AT-242

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.
GI
MA
EM
LC
EC
FE
TF
PD
AX
SU
BR
ST
RS
BT
HA
SC
EL
IDX
TROUBLE DIAGNOSES FOR SYMPTOMS
12. A/T Does Not Perform Lock-up
AT-245

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.
GI
MA
EM
LC
EC
FE
TF
PD
AX
SU
BR
ST
RS
BT
HA
SC
EL
IDX
TROUBLE DIAGNOSES FOR SYMPTOMS
13. A/T Does Not Hold Lock-up Condition
AT-247

15. Engine Speed Does Not Return To Idle
(Light Braking D
4®D3)=NBAT0087SYMPTOM:
IEngine speed does not smoothly return to idle when A/T
shifts from D
4to D3.
IVehicle does not decelerate by engine brake when turning
overdrive control switch OFF.
IVehicle does not decelerate by engine brake when shifting
A/T from ªDº to ª2º position.
1 CHECK SELF-DIAGNOSTIC RESULTS
Does self-diagnosis show damage to overrun clutch solenoid valve circuit after cruise test?
SAT583I
YesorNo
Ye s©Check overrun clutch solenoid valve circuit. Refer to ªDTC P1760º, AT-185.
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.
TROUBLE DIAGNOSES FOR SYMPTOMS
15. Engine Speed Does Not Return To Idle (Light Braking D4®D3)
AT-250