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-104
< SERVICE INFORMATION >
DTC P0778 PRESSURE CONTROL SOLENOID B ELECTRICAL (SEC PRES-
SURE SOLENOID VALVE)
DTC P0778 PRESSURE CONTROL SOLENOID B ELECTRICAL (SEC
PRESSURE SOLENOID VALVE)
DescriptionINFOID:0000000001703565
• 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 oil pump discharge
pressure to suit the driving condition in response to a signal sent from the TCM.
CONSULT-III Reference Value in Data Monitor ModeINFOID:0000000001703566
Remarks: Specification data are reference values.
On Board Diagnosis LogicINFOID:0000000001703567
• This is an OBD-II self-diagnostic item.
• Diagnostic trouble code “P0778 PRS CNT SOL/B CIRC” with CONSULT-III is detected under the following
conditions.
- TCM detects an improper voltage drop when it tries to operate the solenoid valve.
- When TCM compares target value with monitor value and detects an irregularity.
Possible CauseINFOID:0000000001703568
• Harness or connectors
(Solenoid circuit is open or shorted.)
• Pressure control solenoid valve B (Secondary pressure solenoid valve)
DTC Confirmation ProcedureINFOID:0000000001703569
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.
2. Select “DATA MONITOR” mode for “TRANSMISSION” with CONSULT-III.
3. Start engine and wait at least 5 seconds.
4. If DTC is detected, go to CVT-106, "
Diagnosis Procedure" .
WITH GST
Follow the procedure “WITH CONSULT-III”.
Item name Condition Display value (Approx.)
ISOLT3 Secondary pressure low - Secondary pressure high 0.8 - 0.0 A
SOLMON3“N” position idle 0.6 - 0.7 A
When stalled 0.4 - 0.6 A
DTC P0778 PRESSURE CONTROL SOLENOID B ELECTRICAL (SEC PRES-
SURE SOLENOID VALVE)
CVT-105
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Wiring Diagram - CVT - SECPSVINFOID:0000000001703570
TCM TERMINALS AND REFERENCE VALUES
Refer to CVT-45, "TCM Terminal and Reference Value" .
BCWA0676E
CVT-106
< SERVICE INFORMATION >
DTC P0778 PRESSURE CONTROL SOLENOID B ELECTRICAL (SEC PRES-
SURE SOLENOID VALVE)
Diagnosis Procedure
INFOID:0000000001703571
1. CHECK INPUT SIGNAL
With CONSULT-III
1. Start engine.
2. Select “MAIN SIGNALS” in “DATA MONITOR” mode for “TRANSMISSION” with CONSULT-III.
3. Read out the value of “ISOLT3”.
Without CONSULT-III
1. Start engine.
2. Check voltage between TCM connector terminal and ground.
3. Turn ignition switch OFF.
4. Disconnect TCM connector.
5. Check if there is continuity between connector terminal and ground.
OK or NG
OK >> GO TO 5.
NG >> GO TO 2.
2.CHECK PRESSURE CONTROL SOLENOID VALVE B (SECONDARY PRESSURE SOLENOID VALVE)
CIRCUIT
1. Turn ignition switch OFF.
2. Disconnect TCM connector.
3. Check resistance between TCM connector terminal and ground.
OK or NG
OK >> GO TO 5.
NG >> GO TO 3.
3.CHECK VALVE RESISTANCE
1. Turn ignition switch OFF.
2. Disconnect CVT unit harness connector.
Item name Condition Display value (Approx.)
ISOLT3Secondary pressure low -
Secondary pressure high0.8 - 0.0 A
Name Connector Terminal ConditionVoltage
(Approx.)
Pressure
control so-
lenoid
valve B
(Second-
ary pres-
sure
solenoid
valve)E31 2 - groundRelease your foot from
the accelerator pedal.5.0 - 7.0 V
Press the accelerator
pedal all the way down.3.0 - 4.0 V
SCIA4506E
Solenoid valve Connector TerminalResistance (Ap-
prox.)
Pressure control solenoid
valve B (Secondary pres-
sure solenoid valve)E31 2 - Ground 3 - 9 Ω
SCIA4507E
DTC P0778 PRESSURE CONTROL SOLENOID B ELECTRICAL (SEC PRES-
SURE SOLENOID VALVE)
CVT-107
< SERVICE INFORMATION >
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3. Check resistance between CVT unit harness connector terminal
and ground.
OK or NG
OK >> GO TO 4.
NG >> Repair or replace damaged parts.
4.CHECK HARNESS BETWEEN TCM AND PRESSURE CONTROL SOLENOID VALVE B (SECONDARY
PRESSURE SOLENOID VALVE)
1. Turn ignition switch OFF.
2. Disconnect TCM connector and CVT unit harness connector.
3. Check continuity between TCM connector terminal and CVT unit
harness connector terminal.
4. If OK, check harness for short to ground and short to power.
5. Reinstall any part removed.
OK or NG
OK >> GO TO 5.
NG >> Repair or replace damaged parts.
5.CHECK DTC
Perform CVT-104, "
DTC Confirmation Procedure" .
OK or NG
OK >>INSPECTION END
NG >> GO TO 6.
6.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 >> 1. Repair or replace damaged parts.
2. Replace the transaxle assembly. Refer to CVT-178, "
Removal and Installation" .
Component InspectionINFOID:0000000001703572
PRESSURE CONTROL SOLENOID VALVE B (SECONDARY PRESSURE SOLENOID VALVE)
1. Turn ignition switch OFF.
2. Disconnect CVT unit harness connector.
Solenoid valve Connector TerminalResistance (Ap-
prox.)
Pressure control solenoid
valve B (Secondary pres-
sure solenoid valve) F46 3 - Ground 3 - 9 Ω
SCIA4688E
Item Connector Terminal Continuity
TCM connector E31 2
Ye s
CVT unit harness connec-
torF46 3
SCIA4689E
CVT-108
< SERVICE INFORMATION >
DTC P0778 PRESSURE CONTROL SOLENOID B ELECTRICAL (SEC PRES-
SURE SOLENOID VALVE)
3. Check resistance between CVT unit harness connector terminal
and ground.
4. If NG, replace the transaxle assembly. Refer to CVT-178,
"Removal and Installation" .
Solenoid Valve Connector TerminalResistance (Ap-
prox.)
Pressure control sole-
noid valve B (Secondary
pressure solenoid valve) F46 3 - Ground 3 - 9 Ω
SCIA4688E
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
CVT-162
< SERVICE INFORMATION >
CVT SHIFT LOCK SYSTEM
CVT SHIFT LOCK SYSTEM
DescriptionINFOID:0000000001703675
• The mechanical key interlock mechanism also operates as a shift lock:
With the ignition switch turned to ON, selector lever cannot be shifted from “P” position to any other position
unless brake pedal is depressed.
With the key removed, selector lever cannot be shifted from “P” position to any other position.
The key cannot be removed unless selector lever is placed in “P” position.
• The shift lock and key interlock mechanisms are controlled by the ON-OFF operation of the shift lock sole-
noid and by the operation of the rotator and slider located inside key cylinder, respectively.
Shift Lock System Electrical Parts LocationINFOID:0000000001703676
1. Key interlock cable 2. Key cylinder 3. Stop lamp switch
4. Brake pedal 5. Shift lock release button 6. Key interlock cable
7. Shift lock solenoid 8. Park position switch
BCIA0034E