engine NISSAN LATIO 2008 Service Repair Manual

DTC P1726 ELECTRIC THROTTLE CONTROL SYSTEM
CVT-131
< SERVICE INFORMATION >
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DTC P1726 ELECTRIC THROTTLE CONTROL SYSTEM
DescriptionINFOID:0000000001703622
Electric throttle control actuator consists of throttle control motor, accelerator pedal position sensor, throttle
position sensor etc. The actuator sends a signal to the ECM, and ECM sends the signal to TCM with CAN
communication.
On Board Diagnosis LogicINFOID:0000000001703623
• This is not an OBD-II self-diagnostic item.
• Diagnostic trouble code “P1726 ELEC TH CONTROL” with CONSULT-III is detected when the electronically
controlled throttle for ECM is malfunctioning.
Possible CauseINFOID:0000000001703624
Harness or connectors
(Sensor circuit is open or shorted.)
DTC Confirmation ProcedureINFOID:0000000001703625
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 let it idle for 5 second.
4. If DTC is detected, go to CVT-131, "
Diagnosis Procedure".
Diagnosis ProcedureINFOID:0000000001703626
1.CHECK DTC WITH ECM
With CONSULT-III
1. Turn ignition switch ON. (Do not start engine.)
2. Select “SELF-DIAG RESULTS” mode for “ENGINE” with CONSULT-III. Refer to EC-109, "
CONSULT-II
Function (ENGINE)".
OK or NG
OK >> GO TO 2.
NG >> Check the DTC Detected Item. Refer to EC-109, "
CONSULT-II Function (ENGINE)".
• If CAN communication line is detected, go to CVT-56
.
2.CHECK DTC
Perform CVT-131, "
DTC Confirmation Procedure".
OK or NG
OK >>INSPECTION END
NG >> GO TO 3.
3.DETECT MALFUNCTIONING ITEM
Check the following:
• The TCM pin terminals for damage or loose connection with harness connector.
OK or NG
OK >> Replace TCM. Refer to CVT-8, "Service After Replacing TCM and Transaxle Assembly".
NG >> Repair or replace damaged parts.

CVT-132
< SERVICE INFORMATION >
DTC P1740 LOCK-UP SELECT SOLENOID VALVE CIRCUIT
DTC P1740 LOCK-UP SELECT SOLENOID VALVE CIRCUIT
DescriptionINFOID:0000000001703627
• The lock-up select solenoid valve is included in the control valve assembly.
• The lock-up select solenoid valve controls lock-up clutch pressure or forward clutch pressure (reverse brake
pressure).
• When controlling lock-up clutch, the valve is turned OFF. When controlling forward clutch, it is turned ON.
CONSULT-III Reference Value in Data Monitor ModeINFOID:0000000001703628
On Board Diagnosis LogicINFOID:0000000001703629
• This is an OBD-II self-diagnostic item.
• Diagnostic trouble code “P1740 LU-SLCT SOL/CIRC” with CONSULT-III is detected under the following con-
ditions.
- When TCM compares target value with monitor value and detects an irregularity.
Possible CauseINFOID:0000000001703630
• Lock-up select solenoid valve
• Harness or connectors
(Solenoid circuit is open or shorted.)
DTC Confirmation ProcedureINFOID:0000000001703631
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 conditions for at least 5 consecutive seconds.
RANGE: “D” position and “N” position
(At each time, wait for 5 seconds.)
4. If DTC is detected, go to CVT-134, "
Diagnosis Procedure" .
WITH GST
Follow the procedure “WITH CONSULT-III”.
Item name Condition Display value
LUSEL SOL OUTSelector lever in “P” and “N” positions ON
Wait at least for 5 seconds with the selector lever
in “R”, “D” and “L” positionsOFF

CVT-136
< SERVICE INFORMATION >
DTC P1745 LINE PRESSURE CONTROL
DTC P1745 LINE PRESSURE CONTROL
DescriptionINFOID:0000000001703635
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.
On Board Diagnosis LogicINFOID:0000000001703636
• This is not an OBD-II self-diagnostic item.
• Diagnostic trouble code “P1745 L/PRESS CONTROL” with CONSULT-III is detected when TCM detects the
unexpected line pressure.
Possible CauseINFOID:0000000001703637
TCM
DTC Confirmation ProcedureINFOID:0000000001703638
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. 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. If DTC is detected, go to CVT-136, "
Diagnosis Procedure" .
Diagnosis ProcedureINFOID:0000000001703639
1.CHECK DTC
1. Turn ignition switch ON. (Do not start engine.)
2. Select “SELF-DIAG RESULTS” mode for “TRANSMISSION” with CONSULT-III.
3. Erase self-diagnostic results. Refer to CVT-26, "
OBD-II Diagnostic Trouble Code (DTC)".
4. Turn ignition switch OFF, and wait for 10 seconds or more.
5. Start engine.
6. Confirm self-diagnostic results again. Refer to CVT-47, "
CONSULT-III Function (TRANSMISSION)" .
Is the
“P1745 L/PRESS CONTROL” displayed?
YES >> Replace TCM. Refer to CVT-8, "Service After Replacing TCM and Transaxle Assembly" .
NO >>INSPECTION END

DTC P1777 STEP MOTOR - CIRCUIT
CVT-139
< SERVICE INFORMATION >
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Diagnosis ProcedureINFOID:0000000001703646
1.CHECK INPUT SIGNALS
With CONSULT-III
1. Start engine.
2. Select “SELECTION FROM MENU” in “DATA MONITOR” mode for “TRANSMISSION” with CONSULT-III.
3. Start vehicle and read out the value of “STM STEP”, “SMCOIL A”, “SMCOIL B”, “SMCOIL C”, and
“SMCOIL D”.
OK or NG
OK >> GO TO 4.
NG >> GO TO 2.
2.CHECK HARNESS BETWEEN TCM AND STEP MOTOR
1. Turn ignition switch OFF.
2. Disconnect CVT unit connector and TCM 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. If OK, check continuity between body ground and CVT assembly.
6. Reinstall any part removed.
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 STEP MOTOR
Check step motor. Refer to CVT-140, "
Component Inspection" .
OK or NG
OK >> GO TO 4.
NG >> Repair or replace damaged parts.
4.CHECK DTC
Perform CVT-137, "
DTC Confirmation Procedure" .
OK or NG
OK >>INSPECTION END
NG >> GO TO 5.
Item name Condition Display value (Approx.)
STM STEP
During driving−20 step - 180 step
SMCOIL A
Changes ON⇔OFF. SMCOIL B
SMCOIL C
SMCOIL D
Item Connector Terminal Continuity
TCM E31 11
Ye s
CVT unit harness connector F46 6
TCM E31 12
Ye s
CVT unit harness connector F46 7
TCM E31 20
Ye s
CVT unit harness connector F46 8
TCM E31 21
Ye s
CVT unit harness connector F46 9
SCIA4695E

DTC P1778 STEP MOTOR - FUNCTION
CVT-141
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DTC P1778 STEP MOTOR - FUNCTION
DescriptionINFOID:0000000001703648
• The step motor is included in the control valve assembly.
• The step motor's 4 aspects of ON/OFF change according to the signal from TCM. As a result, the flow of line
pressure to primary pulley is changed and pulley ratio is controlled.
• This diagnosis item is detected when electrical system is OK, but mechanical system is NG.
• This diagnosis item is detected when the state of the changing the speed mechanism in unit does not oper-
ate normally.
CONSULT-III Reference Value in Data Monitor ModeINFOID:0000000001703649
Remarks: Specification data are reference values.
On Board Diagnosis LogicINFOID:0000000001703650
• This is an OBD-II self-diagnostic item.
• Diagnostic trouble code “P1778 STEP MOTR/FNC” with CONSULT-III is detected under the following condi-
tions.
- When not changing the pulley ratio according to the instruction of TCM.
Possible CauseINFOID:0000000001703651
Step motor
DTC Confirmation ProcedureINFOID:0000000001703652
CAUTION:
• Always drive vehicle at a safe speed.
• Before starting “DTC Confirmation Procedure”, confirm “Hi” or “Mid” or “Low” fixation by “PRI
SPEED” and “VEHICLE SPEED” on “DATA MONITOR MODE”.
• If hi-geared fixation occurred, go to CVT-142, "
Diagnosis Procedure".
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. 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-142, "
Diagnosis Procedure".
WITH GST
Follow the procedure “WITH CONSULT-III”.
Item name Condition Display value (Approx.)
STM STEP
During driving−20 step - 180 step
GEAR RATIO2.56 - 0.43

CVT-142
< SERVICE INFORMATION >
DTC P1778 STEP MOTOR - FUNCTION
Diagnosis Procedure
INFOID:0000000001703653
1.CHECK STEP MOTOR
With CONSULT-III
It is monitoring whether “GEAR RATIO: 2.56 - 0.43” changes similarly to “STM STEP: −20 - 180” by DATA
MONITOR mode. Refer to CVT-47, "
CONSULT-III Function (TRANSMISSION)".
Without CONSULT-III
Inspect the engine speed (rise and descend), vehicle speed, throttle position, and check shift change. Refer to
CVT-181, "
Vehicle Speed When Shifting Gears".
OK or NG
OK >>INSPECTION END
NG >> Replace the transaxle assembly. Refer to CVT-178, "
Removal and Installation".

CVT-148
< SERVICE INFORMATION >
SHIFT POSITION INDICATOR CIRCUIT
SHIFT POSITION INDICATOR CIRCUIT
DescriptionINFOID:0000000001703659
TCM sends the switch signals to combination meter via CAN communication line. Then selector lever position
is indicated on the shift position indicator.
CONSULT-III Reference Value in Data Monitor ModeINFOID:0000000001703660
Diagnosis ProcedureINFOID:0000000001703661
1.CHECK INPUT SIGNALS
With CONSULT-III
1. Start engine.
2. Select “MAIN SIGNALS” in “DATA MONITOR” mode for “TRANSMISSION” with CONSULT-III and read
out the value of “RANGE”.
3. Check that the following three positions or indicators are same.
- Actual position of the selector lever
- “RANGE” on CONSULT-III screen
- Shift position indicator in the combination meter
OK or NG
OK >>INSPECTION END
NG >> Check the following.
SHIFT POSITION INDICATOR SYMPTOM CHART
Item name Condition Display value
RANGESelector lever in “N” or “P” position. N·P
Selector lever in “R” position. R
Selector lever in “D” position. D
Selector lever in “L” position. L
Items Presumed location of trouble
Actual position does not change.Park/neutral position switch
• Refer to CVT-65
.
CVT main system (Fail-safe function actuated)
• Refer to CVT-47, "
CONSULT-III Function (TRANSMISSION)".
Shift position indicator in the combination meter does not indicate
any position.
Perform the self-diagnosis for CVT and the combination meter.
• Refer to CVT-47, "
CONSULT-III Function (TRANSMISSION)"
and DI-4
. Actual position changes, but the shift position indicator in the com-
bination meter does not change.
Actual position differs from the shift position indicator in the com-
bination meter.
Shift position indicator in the combination meter does not indicate
specific position only.Check the combination meter.
• Refer to DI-4
.

TROUBLE DIAGNOSIS FOR SYMPTOMS
CVT-153
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Check again. Refer to CVT-41, "Check before Engine Is Started".
OK or NG
OK >>INSPECTION END
NG >> GO TO 7.
7.CHECK COMBINATION METERS
Check combination meters. Refer to DI-4
OK or NG
OK >>INSPECTION END
NG >> Repair or replace damaged parts.
Engine Cannot Be Started in "P" and "N" PositionINFOID:0000000001703664
SYMPTOM:
•Engine cannot be started with selector lever in “P” or “N” position.
•Engine can be started with selector lever in “D”, “L” or “R” position.
DIAGNOSTIC PROCEDURE
1.CHECK SELF-DIAGNOSTIC RESULTS
Perform self-diagnosis check. Refer to CVT-47, "
CONSULT-III Function (TRANSMISSION)".
Do the self-diagnostic results indicate PNP switch circuit or start signal circuit?
YES >> Check PNP switch circuit or start signal circuit. Refer to CVT-65 or CVT-60.
NO >> GO TO 2.
2.CHECK CVT POSITION
Check CVT position. Refer to CVT-171, "
Checking of CVT Position"
OK or NG
OK >> GO TO 3.
NG >> Adjust CVT position. Refer to CVT-171, "
Adjustment of CVT Position".
3.CHECK STARTING SYSTEM
Check starting system. Refer to SC-8
.
OK or NG
OK >>INSPECTION END
NG >> Repair or replace damaged parts.
In "P" Position, Vehicle Moves Forward or Backward When PushedINFOID:0000000001703665
SYMPTOM:
Vehicle moves when it is pushed forward or backward with selector lever in “P” position.
DIAGNOSTIC PROCEDURE
1.CHECK SELF-DIAGNOSTIC RESULTS
Perform self-diagnosis check. Refer to CVT-47, "
CONSULT-III Function (TRANSMISSION)".
Do the self-diagnostic results indicate PNP switch circuit?
YES >> Check PNP switch circuit. Refer to CVT-65.
NO >> GO TO 2.
2.CHECK CVT POSITION
Check CVT position. Refer to CVT-171, "
Checking of CVT Position"
OK or NG
OK >> GO TO 3.
NG >> Adjust CVT position. Refer to CVT-171, "
Adjustment of CVT Position".
3.CHECK SYMPTOM
Check again. Refer to CVT-41, "
Check at Idle".

CVT-154
< SERVICE INFORMATION >
TROUBLE DIAGNOSIS FOR SYMPTOMS
OK or NG
OK >>INSPECTION END
NG >> Replace the transaxle assembly. Refer to CVT-178, "
Removal and Installation".
In "N" Position, Vehicle MovesINFOID:0000000001703666
SYMPTOM:
Vehicle moves forward or backward when selecting “N” position.
DIAGNOSTIC PROCEDURE
1.CHECK SELF-DIAGNOSTIC RESULTS
Perform self-diagnosis check. Refer to CVT-47, "
CONSULT-III Function (TRANSMISSION)".
Do the self-diagnostic results indicate PNP switch circuit?
YES >> Check PNP switch circuit. Refer to CVT-65.
NO >> GO TO 2.
2.CHECK CVT POSITION
Check CVT position. Refer to CVT-171, "
Checking of CVT Position"
OK or NG
OK >> GO TO 3.
NG >> Adjust CVT position. Refer to CVT-171, "
Adjustment of CVT Position".
3.CHECK CVT FLUID LEVEL
Check CVT fluid level. Refer to MA-19, "
Checking CVT Fluid".
OK or NG
OK >> GO TO 4.
NG >> Refill CVT fluid.
4.CHECK SYMPTOM
Check again. Refer to CVT-41, "
Check at Idle".
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 >> Replace the transaxle assembly. Refer to CVT-178, "Removal and Installation".
NG >> Repair or replace damaged parts.
Large Shock "N" → "R" PositionINFOID:0000000001703667
SYMPTOM:
There is large shock when shifting from “N” to “R” position.
DIAGNOSTIC PROCEDURE
1.CHECK SELF-DIAGNOSTIC RESULTS
Perform self-diagnosis check. Refer to CVT-47, "
CONSULT-III Function (TRANSMISSION)".
Is any malfunction detected by self-diagnosis?
YES >> Check the malfunctioning system. Refer to CVT-47, "CONSULT-III Function (TRANSMISSION)".
NO >> GO TO 2.
2.CHECK ENGINE IDLE SPEED
Check the engine idle speed. Refer to EC-73, "
Idle Speed and Ignition Timing Check".
OK or NG

TROUBLE DIAGNOSIS FOR SYMPTOMS
CVT-159
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Vehicle Speed Does Not Change in "D" PositionINFOID:0000000001703672
SYMPTOM:
Vehicle speed does not change in “D” position while the cruise test.
DIAGNOSTIC PROCEDURE
1.CHECK SELF-DIAGNOSTIC RESULTS
Perform self-diagnosis check. Refer to CVT-47, "
CONSULT-III Function (TRANSMISSION)" .
Is any malfunction detected by self-diagnosis?
YES >> Check the malfunctioning system. Refer to CVT-47, "CONSULT-III Function (TRANSMISSION)" .
NO >> GO TO 2.
2.CHECK CVT POSITION
Check CVT position. Refer to CVT-171, "
Checking of CVT Position"
OK or NG
OK >> GO TO 3.
NG >> Adjust CVT position. Refer to CVT-171, "
Adjustment of CVT Position" .
3.CHECK CVT FLUID LEVEL
Check CVT fluid level. Refer to MA-19, "
Checking CVT Fluid" .
OK or NG
OK >> GO TO 4.
NG >> Refill CVT fluid.
4.CHECK LINE PRESSURE
Check line pressure at idle. Refer to CVT-36, "
Inspections before Trouble Diagnosis" .
OK or NG
OK >> GO TO 5.
NG >> Check the malfunctioning item. Refer to CVT-36, "
Inspections before Trouble Diagnosis" .
5.CHECK STALL REVOLUTION
Check stall revolution. Refer to CVT-36, "
Inspections before Trouble Diagnosis" .
OK or NG
OK >> GO TO 6.
NG >> Check the malfunctioning item. Refer to CVT-36, "
Inspections before Trouble Diagnosis" .
6.CHECK SYMPTOM
Check again. Refer to CVT-43, "
Cruise Test" .
OK or NG
OK >>INSPECTION END
NG >> GO TO 7.
7.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 >> Replace the transaxle assembly. Refer to CVT-178, "Removal and Installation" .
NG >> Repair or replace damaged parts.
Vehicle Does Not Decelerate by Engine BrakeINFOID:0000000001703673
SYMPTOM:
Engine brake does not operate when releasing the accelerator pedal while the cruise test.
DIAGNOSTIC PROCEDURE
1.CHECK SELF-DIAGNOSTIC RESULTS