2008 NISSAN LATIO ignition

DTC P1777 STEP MOTOR - CIRCUIT
CVT-137
< SERVICE INFORMATION >
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DTC P1777 STEP MOTOR - CIRCUIT
DescriptionINFOID:0000000001703640
• The step motor is included in the control valve assembly.
• The step motor changes the step with turning 4 coils ON/OFF according to the signal from TCM. As a result,
the flow of line pressure to primary pulley is changed and pulley ratio is controlled
CONSULT-III Reference Value in Data Monitor ModeINFOID:0000000001703641
Remarks: Specification data are reference values.
On Board Diagnosis LogicINFOID:0000000001703642
• This is an OBD-II self-diagnostic item.
• Diagnostic trouble code “P1777 STEP MOTR CIRC” with CONSULT-III is detected under the following con-
ditions.
- When operating step motor ON and OFF, there is no proper change in the voltage of TCM terminal which
corresponds to it.
Possible CauseINFOID:0000000001703643
• Step motor
• Harness or connectors
(Step motor circuit is open or shorted.)
DTC Confirmation ProcedureINFOID:0000000001703644
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. Drive vehicle for at least 5 consecutive seconds.
3. If DTC is detected, go to CVT-139, "
Diagnosis Procedure" .
WITH GST
Follow the procedure “WITH CONSULT-III”.
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

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

CVT-140
< SERVICE INFORMATION >
DTC P1777 STEP MOTOR - CIRCUIT
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.
Component InspectionINFOID:0000000001703647
STEP MOTOR
1. Turn ignition switch OFF.
2. Disconnect CVT unit harness connector.
3. Check resistance between CVT unit harness connector termi-
nals and ground.
4. If NG, replace the transaxle assembly. Refer to CVT-178, "
Removal and Installation" .
Name Connector TerminalResistance (Ap-
prox.)
Step motor F466 - 7
30 Ω
8 - 9
6 - Ground
15 Ω 7 - Ground
8 - Ground
9 - Ground
SCIA4696E

DTC P1778 STEP MOTOR - FUNCTION
CVT-141
< SERVICE INFORMATION >
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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

OVERDRIVE CONTROL SWITCH
CVT-145
< SERVICE INFORMATION >
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Perform the self-diagnosis check. Refer to CVT-47, "CONSULT-III Function (TRANSMISSION)".
Is any malfunction of the
“U1000 CAN COMM CIRCUIT” indicated in the results?
YES >> Check CAN communication line. Refer to CVT-56.
NO >> GO TO 2.
2.CHECK OVERDRIVE CONTROL SWITCH SIGNAL
With CONSULT-III
1. Turn ignition switch ON.
2. Select “ECU INPUT SIGNALS” in “DATA MONITOR” mode for “TRANSMISSION” with CONSULT-III.
3. Read out ON/OFF switching action of the “SPORT MODE SW”.
OK or NG
OK >>INSPECTION END
NG >> GO TO 3.
3.CHECK OVERDRIVE CONTROL SWITCH
Check overdrive control switch. Refer to CVT-146, "
Component Inspection"
OK or NG
OK >> GO TO 4.
NG >> Repair or replace damaged parts.
4.CHECK SELF-DIAGNOSTIC RESULTS (COMBINATION METER)
Perform self-diagnosis check. Refer to DI-11, "
Self-Diagnosis Mode of Combination Meter".
Is any malfunction detected by self-diagnostic?
YES >> Check the malfunctioning system.
NO - 1 >> With intelligent key: GO TO 5.
NO - 2 >> Without intelligent key: GO TO 6.
5.CHECK OVERDRIVE CONTROL SWITCH CIRCUIT
1. Turn ignition switch OFF.
2. Disconnect CVT device connector and combination meter connector.
3. Check continuity between CVT device harness connector (A)
terminal and combination meter harness connector (B) terminal.
Item name Condition Display value
SPORT MODE SWWhile pushing overdrive
cancel switchON
Other conditions OFF
Item Connector Terminal Continuity
CVT device harness connector M38 1
Ye s
Combination meter harness
connectorM24 8
SCIA7949E

CVT-146
< SERVICE INFORMATION >
OVERDRIVE CONTROL SWITCH
4. Check continuity between CVT device harness connector termi-
nal and ground.
5. If OK, check harness for short to ground and short to power.
6. Reinstall any part removed.
OK or NG
OK >>INSPECTION END
NG >> Repair open circuit or short to ground or short to power
in harness or connectors.
6.CHECK OVERDRIVE CONTROL SWITCH CIRCUIT
1. Turn ignition switch OFF.
2. Disconnect CVT device connector and combination meter connector.
3. Check continuity between CVT device harness connector (A)
terminal and combination meter harness connector (B) terminal.
4. Check continuity between CVT device harness connector termi-
nal and ground.
5. If OK, check harness for short to ground and short to power.
6. Reinstall any part removed.
OK or NG
OK >>INSPECTION END
NG >> Repair open circuit or short to ground or short to power
in harness or connectors.
Component InspectionINFOID:0000000001703658
OVERDRIVE CONTROL SWITCH
With Intelligent Key
Check continuity between CVT device harness connector terminals.
Without Intelligent Key
Item Connector Terminal Continuity
CVT device harness connector M38 2 - ground Yes
SCIA7950E
Item Connector Terminal Continuity
CVT device harness connector M38 1
Ye s
Combination meter harness
connectorM24 8
SCIA7951E
Item Connector Terminal Continuity
CVT device harness connector M38 2 - ground Yes
SCIA7952E
Item Condition Connector Terminal Continuity
Overdrive con-
trol switchWhile pushing
overdrive control
switchM38 1 - 2Ye s
Other conditions No
SCIA7942E

CVT-152
< SERVICE INFORMATION >
TROUBLE DIAGNOSIS FOR SYMPTOMS
O/D OFF indicator lamp does not come on for about 2 seconds when turning ignition switch ON.
DIAGNOSTIC PROCEDURE
1.CHECK CAN COMMUNICATION LINE
Perform the self-diagnosis check. Refer to CVT-47, "
CONSULT-III Function (TRANSMISSION)".
Is any malfunction of the
“U1000 CAN COMM CIRCUIT” indicated in the results?
YES >> Check CAN communication line. Refer to CVT-56.
NO >> GO TO 2.
2.CHECK TCM POWER SOURCE
1. Turn ignition switch ON.
2. Check voltage between TCM connector terminals and ground.
Refer to CVT-122, "
Wiring Diagram - CVT - POWER".
OK or NG
OK >> GO TO 4.
NG >> GO TO 3.
3.DETECT MALFUNCTIONING ITEM
Check the following.
• Harness for short or open between ignition switch and TCM connector terminal 10, 19
Refer to CVT-122, "
Wiring Diagram - CVT - POWER".
• 10 A fuse (No.49, located in the IPDM E/R). Refer to CVT-122, "
Wiring Diagram - CVT - POWER".
• Ignition switch. Refer to PG-3
.
OK or NG
OK >> GO TO 4.
NG >> Repair or replace damaged parts.
4.CHECK TCM GROUND CIRCUIT
1. Turn ignition switch OFF.
2. Disconnect TCM connector.
3. Check continuity between TCM connector terminals and ground.
Refer to CVT-122, "
Wiring Diagram - CVT - POWER".
OK or NG
OK >> GO TO 5.
NG >> Repair open circuit or short to ground or short to power
in harness or connectors.
5.DETECT MALFUNCTIONING ITEM
Check the following.
• Harness and fuse for short or open between ignition switch and O/D OFF indicator lamp
Refer to PG-3
.
OK or NG
OK >> GO TO 6.
NG >> Repair or replace damaged parts.
6.CHECK SYMPTOM
NameConnec-
torTerminal Voltage (Approx.)
Power supply E3110 Battery voltage
19 Battery voltage
SCIA4737E
NameConnec-
torTerminal Continuity
Ground E3225
Ye s
48
SCIA2671E

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