2008 NISSAN LATIO ECU

CVT-86
< SERVICE INFORMATION >
DTC P0725 ENGINE SPEED SIGNAL
• If DTC of CAN communication line is detected, go to CVT-56.
3. CHECK INPUT SIGNALS
With CONSULT-III
1. Start engine.
2. Select “ECU INPUT SIGNALS” in “DATA MONITOR” mode for “TRANSMISSION” with CONSULT-III.
3. While monitoring “ENG SPEED SIG”, check for engine speed change corresponding to “ACC PEDAL
OPEN”.
OK or NG
OK >> GO TO 4.
NG >> Check ignition signal circuit. Refer to EC-531
.
4. CHECK DTC
Perform CVT-85, "
DTC Confirmation Procedure".
OK or NG
OK >>INSPECTION END
NG >> GO TO 5.
5. CHECK TCM
1. Check TCM input/output signals. Refer to CVT-45, "
TCM Terminal and Reference Value".
2. If NG, re-check TCM pin terminals for damage or loose connection with harness connector.
OK or NG
OK >>INSPECTION END
NG >> Repair or replace damaged parts.
Item name Condition Display value
ENG SPEED SIG Engine runningClosely matches the ta-
chometer reading.
ACC PEDAL OPENReleased accelerator
pedal - Fully depressed
accelerator pedal0.0/8 - 8.0/8

DTC P0730 BELT DAMAGE
CVT-87
< SERVICE INFORMATION >
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DTC P0730 BELT DAMAGE
DescriptionINFOID:0000000001703525
TCM selects the gear ratio using the engine load (throttle position), the primary pulley revolution speed, and
the secondary pulley revolution speed as input signal. Then it changes the operating pressure of the primary
pulley and the secondary pulley and changes the groove width of the pulley.
CONSULT-III Reference Value in Data Monitor ModeINFOID:0000000001703526
Remarks: Specification data are reference values.
On Board Diagnosis LogicINFOID:0000000001703527
• This is not an OBD-II self-diagnostic item.
• TCM calculates the actual gear ratio with input speed sensor (primary speed sensor) and output speed sen-
sor (secondary speed sensor).
• Diagnostic trouble code “P0730 BELT DAMG” with CONSULT-III is detected, when TCM receives an unex-
pected gear ratio signal.
Possible CauseINFOID:0000000001703528
Transaxle assembly
DTC Confirmation ProcedureINFOID:0000000001703529
CAUTION:
Always drive vehicle at a safe speed.
NOTE:
If “DTC Confirmation Procedure” has been previously performed, always turn ignition switch OFF and
wait at least 10 seconds before performing the next test.
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 “TRANSMISSION” with CONSULT-III.
2. Make sure that output voltage of CVT fluid temperature sensor is within the range below.
ATF TEMP SEN: 1.0 - 2.0 V
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 “DATA MONITOR” mode for “TRANSMISSION” with CONSULT-III.
4. Start engine and maintain the following conditions for at least 30 consecutive seconds.
TEST START FROM 0 km/h (0 MPH)
CONSTANT ACCELERATION: Keep 30 sec or more
VEHICLE SPEED: 10 km/h (6 MPH) or more
ACC PEDAL OPEN: More than 1.0/8
RANGE: “D” position
ENG SPEED: 450 rpm or more
5. If DTC is detected, go to CVT-87, "
Diagnosis Procedure".
Diagnosis ProcedureINFOID:0000000001703530
1.CHECK DTC
Perform CVT-87, "
DTC Confirmation Procedure".
Are any DTC displayed?
YES - 1>> DTC except for “P0730 BELT DAMG” is displayed: Go to Check the DTC detected item. Refer to
CVT-47, "
CONSULT-III Function (TRANSMISSION)".
YES - 2>> DTC for “P0730 BELT DAMG” is displayed: Replace the transaxle assembly. Refer to CVT-178,
"Removal and Installation".
NO >>INSPECTION END
Item name Condition Display value (Approx.)
GEAR RATIO During driving 2.56 - 0.43

CVT-88
< SERVICE INFORMATION >
DTC P0740 TORQUE CONVERTER CLUTCH SOLENOID VALVE
DTC P0740 TORQUE CONVERTER CLUTCH SOLENOID VALVE
DescriptionINFOID:0000000001703531
• The torque converter clutch solenoid valve is included in the control valve assembly.
• The torque converter clutch solenoid valve is activated by the TCM in response to signals sent from the vehi-
cle speed and accelerator pedal position sensors. Lock-up piston operation will then be controlled.
• Lock-up operation, however, is prohibited when CVT fluid temperature is too low.
• When the accelerator pedal is depressed (less than 2.0/8) in lock-up condition, the engine speed should not
change abruptly. If there is a big jump in engine speed, there is no lock-up.
CONSULT-III Reference Value in Data Monitor ModeINFOID:0000000001703532
Remarks: Specification data are reference values.
On Board Diagnosis LogicINFOID:0000000001703533
• This is an OBD-II self-diagnostic item.
• Diagnostic trouble code “P0740 TCC SOLENOID/CIRC” with CONSULT-III is detected under the following
conditions.
- TCM detects an improper voltage drop when it tries to operate the solenoid valve.
Possible CauseINFOID:0000000001703534
• Torque converter clutch solenoid valve
• Harness or connectors
(Solenoid circuit is open or shorted.)
DTC Confirmation ProcedureINFOID:0000000001703535
NOTE:
If “DTC Confirmation Procedure” has been previously performed, always turn ignition switch OFF and
wait at least 10 seconds before performing the next test.
After the repair, touch “ERASE” on “SELF-DIAG RESULTS” and then perform the following procedure to con-
firm the malfunction is eliminated.
WITH CONSULT-III
1. Turn ignition switch ON. (Do not start engine.)
2. Select “DATA MONITOR” mode for “TRANSMISSION” with CONSULT-III and wait at least 10 consecutive
seconds.
3. If DTC is detected, go to CVT-90, "
Diagnosis Procedure" .
WITH GST
Follow the procedure “WITH CONSULT-III”.
Item name Condition Display value (Approx.)
ISOLT1Lock-up OFF 0.0 A
Lock-up ON 0.7 A

DTC P0744 A/T TCC S/V FUNCTION (LOCK-UP)
CVT-93
< SERVICE INFORMATION >
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DTC P0744 A/T TCC S/V FUNCTION (LOCK-UP)
DescriptionINFOID:0000000001703539
• The torque converter clutch solenoid valve is included in the control valve assembly.
• This malfunction is detected when the torque converter clutch does not lock-up as instructed by the TCM.
This is not only caused by electrical malfunction (circuits open or shorted), but also by mechanical malfunc-
tion such as control valve sticking, improper solenoid valve operation, etc.
CONSULT-III Reference Value in Data Monitor ModeINFOID:0000000001703540
Remarks: Specification data are reference values.
On Board Diagnosis LogicINFOID:0000000001703541
• This is an OBD-II self-diagnostic item.
• Diagnostic trouble code “P0744 A/T TCC S/V FNCTN” with CONSULT-III is detected under the following
conditions.
- When CVT cannot perform lock-up even if electrical circuit is good.
- When TCM compares difference value with slip revolution and detects an irregularity.
Possible CauseINFOID:0000000001703542
• Torque converter clutch solenoid valve
• Hydraulic control circuit
DTC Confirmation ProcedureINFOID:0000000001703543
CAUTION:
Always drive vehicle at a safe speed.
NOTE:
If “DTC Confirmation Procedure” has been previously performed, always turn ignition switch OFF and
wait at least 10 seconds before performing the next test.
After the repair, touch “ERASE” on “SELF-DIAG RESULTS” and then perform the following procedure to con-
firm the malfunction is eliminated.
WITH CONSULT-III
1. Turn ignition switch ON. (Do not start engine.)
2. Select “DATA MONITOR” mode for “TRANSMISSION” with CONSULT-III.
3. Start engine and maintain the following condition for at least 30 seconds.
ACC PEDAL OPEN: More than 1.0/8
RANGE: “D” position
[Vehicle speed: Constant speed of more than 40 km/h (25 MPH)]
4. If DTC is detected go to CVT-93, "
Diagnosis Procedure".
WITH GST
Follow the procedure “WITH CONSULT-III”.
Diagnosis ProcedureINFOID:0000000001703544
1.CHECK INPUT SIGNALS
With CONSULT-III
1. Start engine.
2. Select “ECU INPUT SIGNALS” in “DATA MONITOR” mode for “TRANSMISSION” with CONSULT-III.
3. Start vehicle.
4. Check if there is a great difference between “ENG SPEED SIG” and “PRI SPEED SEN”. (Lock-up ON.)
Item name Condition Display value
ENG SPEED SIG Engine running Closely matches the tachometer reading.
PRI SPEED SEN During driving (lock-up ON) Approximately matches the engine speed.

CVT-100
< SERVICE INFORMATION >
DTC P0746 PRESSURE CONTROL SOLENOID A PERFORMANCE (LINE PRES-
SURE SOLENOID VALVE)
DTC P0746 PRESSURE CONTROL SOLENOID A PERFORMANCE (LINE
PRESSURE SOLENOID VALVE)
DescriptionINFOID:0000000001703553
• The pressure control solenoid valve A (line pressure solenoid valve) is included in the control valve assem-
bly.
• The pressure control solenoid valve A (line pressure solenoid valve) regulates the oil pump discharge pres-
sure to suit the driving condition in response to a signal sent from the TCM.
CONSULT-III Reference Value in Data Monitor ModeINFOID:0000000001703554
Remarks: Specification data are reference values.
On Board Diagnosis LogicINFOID:0000000001703555
• This is an OBD-II self-diagnostic item.
• Diagnostic trouble code “P0746 PRS CNT SOL/A FCTN” with CONSULT-III is detected under the following
conditions.
- Unexpected gear ratio was detected in the LOW side due to excessively low line pressure.
Possible CauseINFOID:0000000001703556
• Line pressure control system
• Output speed sensor (Secondary speed sensor)
• Input speed sensor (Primary speed sensor)
DTC Confirmation ProcedureINFOID:0000000001703557
CAUTION:
Always drive vehicle at a safe speed.
NOTE:
If “DTC Confirmation Procedure” has been previously performed, always turn ignition switch OFF and
wait at least 10 seconds before performing the next test.
After the repair, touch “ERASE” on “SELF-DIAG RESULTS” and then perform the following procedure to con-
firm the malfunction is eliminated.
WITH CONSULT-III
1. Turn ignition switch ON and select “DATA MONITOR” mode for “TRANSMISSION” with CONSULT-III.
2. Start engine and maintain the following conditions for at least 10 consecutive seconds. Test start from 0
km/h (0 MPH).
ATF TEMP SEN: 1.0 - 2.0 V
ACC PEDAL OPEN: More than 1.0/8
RANGE: “D” position
VEHICLE SPEED: 10 km/h (6 MPH) More than
Driving location: Driving the vehicle uphill (increased engine load) will help maintain the driving
conditions required for this test.
3. If DTC is detected, go to CVT-100, "
Diagnosis Procedure".
WITH GST
Follow the procedure “WITH CONSULT-III”.
Diagnosis ProcedureINFOID:0000000001703558
1.CHECK INPUT SIGNAL
With CONSULT-III
1. Start engine.
2. Select “MAIN SIGNALS” in “DATA MONITOR” mode for “TRANSMISSION” with CONSULT-III.
3. Start vehicle and read out the value of “PRI PRESS”.
Item name Condition Display value (Approx.)
PRI PRESS “N” position idle 0.4 MPa

CVT-102
< SERVICE INFORMATION >
DTC P0776 PRESSURE CONTROL SOLENOID B PERFORMANCE (SEC PRES-
SURE SOLENOID VALVE)
DTC P0776 PRESSURE CONTROL SOLENOID B PERFORMANCE (SEC
PRESSURE SOLENOID VALVE)
DescriptionINFOID:0000000001703559
• The pressure control solenoid valve B (secondary pressure solenoid valve) is included in the control valve
assembly.
• The pressure control solenoid valve B (secondary pressure solenoid valve) regulates the secondary pres-
sure to suit the driving condition in response to a signal sent from the TCM.
CONSULT-III Reference Value in Data Monitor ModeINFOID:0000000001703560
Remarks: Specification data are reference values.
On Board Diagnosis LogicINFOID:0000000001703561
• This is an OBD-II self-diagnostic item.
• Diagnostic trouble code “P0776 PRS CNT SOL/B FCTN” with CONSULT-III is detected when secondary
pressure is too high or too low compared with the commanded value while driving.
Possible CauseINFOID:0000000001703562
• Harness or connectors
(Solenoid circuit is open or shorted.)
• Pressure control solenoid valve B (Secondary pressure solenoid valve system)
• Transmission fluid pressure sensor A (Secondary pressure sensor)
• Line pressure control system
DTC Confirmation ProcedureINFOID:0000000001703563
CAUTION:
Always drive vehicle at a safe speed.
NOTE:
If “DTC Confirmation Procedure” has been previously performed, always turn ignition switch OFF and
wait at least 10 seconds before performing the next test.
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 “TRANSMISSION” with CONSULT-III.
2. Start engine and maintain the following conditions for at least 30 consecutive seconds.
ATF TEMP SEN: 1.0 - 2.0 V
ACC PEDAL OPEN: More than 1.0/8
RANGE: “D” position
VEHICLE SPEED: 10 km/h (6 MPH) More than
Driving location: Driving the vehicle uphill (increased engine load) will help maintain the driving
conditions required for this test.
3. If DTC is detected, go to CVT-102, "
Diagnosis Procedure".
WITH GST
Follow the procedure “WITH CONSULT-III”.
Diagnosis ProcedureINFOID:0000000001703564
1.CHECK INPUT SIGNAL
With CONSULT-III
1. Start engine.
2. Select “MAIN SIGNALS” in “DATA MONITOR” mode for “TRANSMISSION” with CONSULT-III.
3. Start vehicle and read out the value of “SEC PRESS”.
Item name Condition Display value (Approx.)
SEC PRESS “N” position idle 0.8 MPa

DTC P0840 TRANSMISSION FLUID PRESSURE SENSOR A CIRCUIT (SEC
PRESSURE SENSOR)
CVT-109
< SERVICE INFORMATION >
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DTC P0840 TRANSMISSION FLUID PRESSURE SENSOR A CIRCUIT
(SEC PRESSURE SENSOR)
DescriptionINFOID:0000000001703573
• The transmission fluid pressure sensor A (secondary pressure sensor) is included in the control valve
assembly.
• The transmission fluid pressure sensor A (secondary pressure sensor) detects secondary pressure of CVT
and sends TCM the signal.
CONSULT-III Reference Value in Data Monitor ModeINFOID:0000000001703574
Remarks: Specification data are reference values.
On Board Diagnosis LogicINFOID:0000000001703575
• This is an OBD-II self-diagnostic item.
• Diagnostic trouble code “P0840 TR PRS SENS/A CIRC” with CONSULT-III is detected when TCM detects
an improper voltage drop when it receives the sensor signal.
Possible CauseINFOID:0000000001703576
• Transmission fluid pressure sensor A (Secondary pressure sensor)
• Harness or connectors
(Switch circuit is open or shorted.)
DTC Confirmation ProcedureINFOID:0000000001703577
NOTE:
If “DTC Confirmation Procedure” has been previously performed, always turn ignition switch OFF and
wait at least 10 seconds before performing the next test.
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 “TRANSMISSION” with CONSULT-III.
2. Make sure that output voltage of line temperature sensor is within the range below.
ATF TEMP SEN: 1.0 - 2.0 V
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. Start engine and wait for at least 5 consecutive seconds.
4. If DTC is detected, go to CVT-111, "
Diagnosis Procedure" .
WITH GST
Follow the procedure “WITH CONSULT-III”.
Item name Condition Display value (Approx.)
SEC HYDR SEN
“N” position idle1.0 V
SEC PRESS0.8 MPa

DTC P0840 TRANSMISSION FLUID PRESSURE SENSOR A CIRCUIT (SEC
PRESSURE SENSOR)
CVT-111
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Diagnosis ProcedureINFOID:0000000001703579
1.CHECK INPUT SIGNAL
With CONSULT-III
1. Start engine.
2. Select “ECU INPUT SIGNALS” in “DATA MONITOR” mode for “TRANSMISSION” with CONSULT-III.
3. Start vehicle and read out the value of “SEC HYDR SEN”.
Without CONSULT-III
1. Start engine.
2. Check voltage between TCM connector terminal and ground.
OK or NG
OK >> GO TO 5.
NG >> GO TO 2.
2.CHECK SENSOR POWER AND SENSOR GROUND
1. Turn ignition switch ON. (Do not start engine)
2. Check voltage between TCM connector terminals.
OK or NG
OK >> GO TO 4.
NG >> GO TO 3.
3. CHECK HARNESS BETWEEN TCM AND CVT UNIT HARNESS CONNECTOR (SENSOR POWER AND
SENSOR GROUND)
1. Turn ignition switch OFF.
2. Disconnect TCM connector and CVT unit harness connector.
3. Check continuity between TCM connector terminals and CVT
unit harness connector terminals.
4. If OK, check harness for short to ground and short to power.
5. Reinstall any part removed.
OK or NG
Item name Condition Display value (Approx.)
SEC HYDR SEN “N” position idle 1.0 V
Name Connector Terminal ConditionVoltage
(Approx.)
Transmission
fluid pressure
sensor A
(Secondary
pressure sen-
sor)E32 37 - Ground “N” position idle 1.0 V
SCIA4508E
Item Connector TerminalData (Ap-
prox.)
TCM connector E32 46 - 42 5.0 V
SCIA2367E
Item Connector Terminal Continuity
TCM E32 42
Ye s
CVT unit harness connector F46 19
TCM E32 46
Ye s
CVT unit harness connector F46 20
SCIA4681E