2008 NISSAN LATIO service

DTC P0740 TORQUE CONVERTER CLUTCH SOLENOID VALVE
AT-123
< SERVICE INFORMATION >
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• Check resistance between terminal and ground.
Operation Check
• Check solenoid valve by listening for its operating sound while
applying battery voltage to the terminal and ground.
Solenoid valve Connector Terminal Resistance (Approx.)
Torque converter
clutch solenoid valveF30 5 - Ground 5 - 20 Ω
SCIA2063E
SCIA2066E

AT-124
< SERVICE INFORMATION >
DTC P0744 A/T TCC S/V FUNCTION (LOCK-UP)
DTC P0744 A/T TCC S/V FUNCTION (LOCK-UP)
DescriptionINFOID:0000000001703260
• This malfunction will not be detected while the OD OFF indicator lamp is indicating another self-diagnosis
malfunction.
• This 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 electrical 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-III Reference Value in Data Monitor ModeINFOID:0000000001703261
Remarks: Specification data are reference values.
On Board Diagnosis LogicINFOID:0000000001703262
• This is an OBD-II self-diagnostic item.
• Diagnostic trouble code “P0744 A/T TCC S/V FNCTN” with CONSULT-III is detected when A/T cannot per-
form lock-up even if electrical circuit is good.
• This 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 malfunc-
tion.
This malfunction will be caused when shift solenoid valve B is stuck closed.
• Gear positions supposed by TCM are as follows.
In case of gear position with no malfunctions: 1, 2, 3 and 4 positions
In case of gear position with shift solenoid valve B stuck closed: 1, 2, 2 and 1* positions to each gear position
above
*: “P0744 A/T TCC S/V FNCTN” is detected.
Possible CauseINFOID:0000000001703263
• Line pressure solenoid valve
• Torque converter clutch solenoid valve
• Each clutch
• Hydraulic control circuit
DTC Confirmation ProcedureINFOID:0000000001703264
CAUTION:
• Always drive vehicle at a safe speed.
• If performing this “DTC Confirmation Procedure” again, always turn ignition switch OFF and wait at
least 10 seconds before continuing.
After the repair, perform the following procedure to confirm the malfunction is eliminated.
WITH CONSULT-III
1. Start engine and select “DATA MONITOR” mode for “A/T” with CONSULT-III.
2. Touch “START”.
3. Make sure that output voltage of A/T fluid temperature sensor is within the range below.
FLUID TEMP SE: 0.4 - 1.5 V
If out of range, drive vehicle to decrease voltage (warm up the fluid) or stop engine to increase voltage
(cool down the fluid).
4. Select “TCC S/V FNCTN P0744” of “DTC WORK SUPPORT” mode for “A/T” with CONSULT-III and touch
“START”.
Item name Condition Display value (Approx)
TCC S/V DUTY Lock-up OFF ⇔ Lock-up ON 4% ⇔ 94%

DTC P0744 A/T TCC S/V FUNCTION (LOCK-UP)
AT-125
< SERVICE INFORMATION >
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5. Accelerate vehicle to more than 80 km/h (50 MPH) and maintain the following conditions continuously
until “TESTING” has turned to “COMPLETE”. (It will take approximately 30 seconds after “TESTING”
shows.)
THROTTLE POSI: 1.0/8 - 2.0/8 (at all times during step 4)
SLCT LVR POSI: “D” position
TCC S/V DUTY: More than 94%
VEHICLE SPEED: Constant speed of more than 80 km/h (50 MPH)
-Make sure that “GEAR” shows “4”.
-For shift schedule, refer to AT-61, "
Vehicle Speed at Which Gear Shifting Occurs".
-If “TESTING” does not appear on CONSULT-III for a long time, select “SELF-DIAG RESULTS”. In
case a DTC other than “P0744 A/T TCC S/V FNCTN” is shown, refer to AT-73, "
CONSULT-III Func-
tion (A/T)".
6. Make sure that “OK” is displayed. (If “NG” is displayed, refer to “DIAGNOSTIC PROCEDURE”.)
Refer to AT-125, "
Diagnosis Procedure".
Refer to AT-61, "
Vehicle Speed at Which Lock-up Occurs/Releases".
WITH GST
Follow the procedure “WITH CONSULT-III”.
Diagnosis ProcedureINFOID:0000000001703265
1.CHECK SHIFT-UP (D3 TO D4)
During AT-55, "
Cruise Test - Part 1".
Does A/T shift from D
3 to D4 at the specified speed?
YES >> GO TO 11.
NO >> GO TO 2.
2.CHECK LINE PRESSURE
Perform line pressure test. Refer to AT-48, "
Inspections Before Trouble Diagnosis".
OK or NG
OK >> GO TO 3.
NG >> GO TO 6.
3.CHECK CONTROL VALVE
1. Disassemble control valve assembly. Refer to AT-263, "
Control Valve Assembly".
2. Check to ensure that:
- Valve, sleeve and plug slide along valve bore under their own weight.
- Valve, sleeve and plug are free from burrs, dents and scratches.
- Control valve springs are free from damage, deformation and fatigue.
- Hydraulic line is free from obstacles.
OK or NG
OK >> GO TO 4.
NG >> Repair control valve.
4.CHECK SHIFT-UP (D3 TO D4)
SCIA7190E

AT-126
< SERVICE INFORMATION >
DTC P0744 A/T TCC S/V FUNCTION (LOCK-UP)
During AT-55, "Cruise Test - Part 1".
Does A/T shift from D
3 to D4 at the specified speed?
YES >> GO TO 5.
NO >> Check control valve again. Repair or replace control
valve assembly.
5.CHECK DTC
Perform AT-124, "
DTC Confirmation Procedure".
OK or NG
OK >>INSPECTION END
NG >> GO TO 11. Check for proper lock-up.
6.CHECK VALVE RESISTANCE
1. Remove control valve assembly. Refer to AT-216, "
Control Valve Assembly and Accumulators".
- Line pressure solenoid valve
2. Check resistance between terminal cord assembly harness con-
nector terminal and ground. Refer to AT-130, "
Wiring Diagram -
AT - L P S V".
OK or NG
OK >> GO TO 7.
NG >> Replace solenoid valve assembly.
7.CHECK VALVE OPERATION
1. Remove control valve assembly. Refer to AT-216, "
Control Valve Assembly and Accumulators".
- Line pressure solenoid valve
2. Check solenoid valve by listening for its operating sound while
applying battery voltage to the terminal and ground. Refer to AT-
130, "Wiring Diagram - AT - LPSV".
OK or NG
OK >> GO TO 8.
NG >> Replace solenoid valve assembly.
8.CHECK CONTROL VALVE
1. Disassemble control valve assembly. Refer to AT-263, "
Control Valve Assembly".
2. Check line pressure circuit valves for sticking.
- Pressure regulator valve
- Pilot valve
- Pressure modifier valve
OK or NG
OK >> GO TO 9.
NG >> Repair control valve.
9.CHECK SHIFT-UP (D3 TO D4)
SCIA7190E
Solenoid valve Connectror Terminal Resistance (Approx.)
Line pressure solenoid
valveF30 4 - Ground 2.5 - 5 Ω
SCIA3457E
SCIA3275E

DTC P0744 A/T TCC S/V FUNCTION (LOCK-UP)
AT-127
< SERVICE INFORMATION >
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During AT-55, "Cruise Test - Part 1".
Does A/T shift from D
3 to D4 at the specified speed?
YES >> GO TO 10.
NO >> Check control valve again. Repair or replace control
valve assembly.
10.CHECK DTC
Perform AT-124, "
DTC Confirmation Procedure".
OK or NG
OK >>INSPECTION END
NG >> GO TO 11. Check for proper lock-up.
11 .CHECK LOCK-UP
During AT-55, "
Cruise Test - Part 1".
A/T perform lock-up at the specified speed?
YES >> Perform “Cruise test — Part 1” again and return to the
start point of this test group.
NO >> GO TO 12.
12.CHECK VALVE RESISTANCE
1. Remove control valve assembly. Refer to AT-216, "
Control Valve Assembly and Accumulators".
- Torque converter clutch solenoid valve
2. Check resistance between terminal cord assembly harness con-
nector terminal and ground. Refer to AT-120, "
Wiring Diagram -
AT - T C V".
OK or NG
OK >> GO TO 13.
NG >> Replace solenoid valve assembly.
13.CHECK VALVE OPERATION
1. Remove control valve assembly. Refer to AT-216, "
Control Valve Assembly and Accumulators".
- Torque converter clutch solenoid valve
SCIA7190E
SCIA7191E
Solenoid valve Connectror Terminal Resistance (Approx.)
Torque converter clutch
solenoid valveF30 5 - Ground 5 - 20 Ω
SCIA2063E

AT-128
< SERVICE INFORMATION >
DTC P0744 A/T TCC S/V FUNCTION (LOCK-UP)
2. Check solenoid valve by listening for its operating sound while
applying battery voltage to the terminal and ground. Refer to AT-
120, "Wiring Diagram - AT - TCV".
OK or NG
OK >> GO TO 14.
NG >> Replace solenoid valve assembly.
14.CHECK CONTROL VALVE
1. Disassemble control valve assembly. Refer to AT-263, "
Control Valve Assembly".
2. Check control valves for sticking.
- Torque converter clutch control valve
- Torque converter clutch relief valve
OK or NG
OK >> GO TO 15.
NG >> Repair control valve.
15.CHECK LOCK-UP
During AT-55, "
Cruise Test - Part 1".
A/T perform lock-up at the specified speed?
YES >> GO TO 16.
NO >> Check control valve again. Repair or replace control
valve assembly.
16.CHECK DTC
Perform AT-124, "
DTC Confirmation Procedure".
OK or NG
OK >>INSPECTION END
NG >> Perform “Cruise test — Part 1” again and return to the start point of this test group.
SCIA2066E
SCIA7191E

DTC P0745 LINE PRESSURE SOLENOID VALVE
AT-129
< SERVICE INFORMATION >
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DTC P0745 LINE PRESSURE SOLENOID VALVE
DescriptionINFOID:0000000001703266
The line pressure solenoid valve regulates the oil pump discharge pressure to suit the driving condition in
response to signals sent from the TCM.
The line pressure duty cycle value is not constant when the closed throttle position switch is ON. To
confirm the line pressure duty cycle at low-pressure, the accelerator (throttle) should be open until the
closed throttle position switch is OFF.
CONSULT-III Reference Value in Data Monitor ModeINFOID:0000000001703267
Remarks: Specification data are reference values.
On Board Diagnosis LogicINFOID:0000000001703268
• This is an OBD-II self-diagnostic item.
• Diagnostic trouble code “P0745 LINE PRESSURE S/V” with CONSULT-III or 11th judgement flicker without
CONSULT-III is detected when TCM detects an improper voltage drop while it tries to operate the solenoid
valve.
Possible CauseINFOID:0000000001703269
• Harness or connector
(The solenoid circuit is open or shorted.)
• Line pressure solenoid valve
DTC Confirmation ProcedureINFOID:0000000001703270
CAUTION:
If performing this “DTC Confirmation Procedure” again, always turn ignition switch OFF and wait at
least 10 seconds before continuing.
After the repair, perform the following procedure to confirm the malfunction is eliminated.
WITH CONSULT-III
1. Turn ignition switch ON and select “DATA MONITOR” mode for “A/T” with CONSULT-III.
2. Touch “START”.
3. Depress accelerator pedal completely and wait at least 1 second.
4. If the check result is NG, go to AT-131, "
Diagnosis Procedure" .
WITH GST
Follow the procedure “WITH CONSULT-III”.
WITHOUT CONSULT-III
1. Start engine.
2. With brake pedal depressed, shift the lever from “P”→“N”→“D”→“N”→“P” positions.
3. Perform self-diagnosis. Refer to AT-78, "
Diagnosis Procedure without CONSULT-III" .
4. If the check result is NG, go to AT-131, "
Diagnosis Procedure" .
Item name Condition Display value (Approx.)
LINE PRES DTYSmall throttle opening (Low line pressure) ⇔ Large
throttle opening (High line pressure)0% ⇔ 94%

AT-130
< SERVICE INFORMATION >
DTC P0745 LINE PRESSURE SOLENOID VALVE
Wiring Diagram - AT - LPSV
INFOID:0000000001703271
TCM TERMINALS AND REFERENCE VALUES
Refer to AT-71, "TCM Terminal and Reference Value".
BCWA0654E