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-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
< SERVICE INFORMATION >
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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
CVT-164
< SERVICE INFORMATION >
CVT SHIFT LOCK SYSTEM
•Selector lever can be moved from “P” position with ignition key in ON position and brake pedal
released.
•Selector lever can be moved from “P” position when ignition switch is removed from key cylinder.
SYMPTOM 2:
•Ignition key cannot be removed when selector lever is set to “P” position.
•Ignition key can be removed when selector lever is set to any position except “P” position.
1.CHECK KEY INTERLOCK CABLE
Check key interlock cable for damage.
OK or NG
OK >> GO TO 2.
NG >> Repair key interlock cable. Refer to AT-213, "
Removal and Installation".
2.CHECK CVT POSITION
Check CVT position. Refer to CVT-171, "
Checking of CVT Position".
OK or NG
OK >> GO TO 3.
NG >> Adjust control cable. Refer to CVT-171, "
Adjustment of CVT Position".
3.CHECK SHIFT LOCK SOLENOID AND PARK POSITION SWITCH
1. Turn ignition switch ON. (Do not start engine.)
2. Selector lever is set in “P” position.
3. Check operation sound.
OK or NG
OK >>INSPECTION END
NG - 1 >> With intelligent key: GO TO 4.
NG - 2 >> Without intelligent key: GO TO 5.
4.CHECK POWER SOURCE
1. Turn ignition switch ON. (Do not start engine.)
2. Check voltage between CVT device harness connector terminal
5 and ground.
OK or NG
OK >> GO TO 8.
NG >> GO TO 6.
5.CHECK POWER SOURCE
1. Turn ignition switch ON. (Do not start engine.)
Condition Brake pedal Operation sound
When ignition switch is turned to ON position and selector lever is set in
“P” position.Depressed Yes
Released No
Voltage:
Brake pedal depressed: Battery voltage
Brake pedal released: 0V
SCIA7934E
SHIFT CONTROL SYSTEM
CVT-171
< SERVICE INFORMATION >
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1. Set selector lever knob (1) in “N” position.
2. Slide knob cover (2) downward.
3. Pull out lock pin (3) from selector lever knob (1).
4. Remove selector lever knob (1) and knob cover (2) as a set from
selector lever.
CAUTION:
Do not push selector button.
INSTALLATION
1. Insert lock pin (1) to selector lever knob (2).
2. Install knob cover (3) to selector lever knob (2).
3. Set selector lever in “N” position.
4. Install selector lever knob over selector lever until a click is felt.
CAUTION:
• Do not tilt selector lever knob when installing. Install it
straight, and do not tap or apply any shock to install it.
• Do not push selector button.
Adjustment of CVT PositionINFOID:0000000001703682
CAUTION:
Make sure that parking brake is applied before adjustment.
1. Loosen the control cable nut (A) and place the manual lever (1)
in “P” position.
2. Place selector lever in “P” position.
3. Push the control cable (2) in with a load of 9.8 N (approximately
1 kg, 2.2 lb). Release the control cable and temporarily tighten
the control cable nut.
NOTE:
Do not move the manual lever. Make sure the manual lever
stays in the “P” position.
4. Tighten the control cable nut.
CAUTION:
Secure the manual lever when tightening nut.
5. Check the operation of the CVT. Refer to CVT-171, "
Checking of CVT Position".
Checking of CVT PositionINFOID:0000000001703683
1. Place selector lever in “P” position, and turn ignition switch ON. (Do not start engine.)
2. Make sure selector lever can be shifted to other than “P” position when brake pedal is depressed. Also
make sure selector lever can be shifted from “P” position only when brake pedal is depressed.
3. Move the selector lever and check for excessive effort, sticking, noise or rattle.
4. Confirm the selector lever stops at each position with the feel of engagement when it is moved through all
the positions. Check that the actual position of the selector lever matches the position shown by the shift
position indicator and the manual lever on the transaxle.
SCIA6971E
SCIA6972E
Control cable nut: Refer to CVT-167, "Removal
and Installation".
WCIA0608E