P1777

P1777 STEP MOTOR

Description

- Step motor changes step by turning 4 coils ON or OFF according to signal from TCM.
- By changing step, step motor controls outward flow and inward flow of line pressure to primary pulley, determines the primary pulley position, and controls gear ratio.


DTC Logic


DTC DETECTION LOGIC







DTC CONFIRMATION PROCEDURE


1. PRECONDITIONING

Immediately after performing any "DTC CONFIRMATION PROCEDURE", always turn ignition switch OFF.
Then wait at least 10 seconds before performing the next test.
- GO TO 2.

2. PERFORM DTC CONFIRMATION PROCEDURE

With CONSULT
1.Start the engine.
2.Select "Data Monitor" in "TRANSMISSION".
3.Select "RANGE" and "VEHICLE SPEED".
4.Maintain the following conditions for 1 seconds or more.

RANGE :D
VEHICLE SPEED :More than 20 km/h (12 MPH)

5.Stop the vehicle.
6.Select "Self Diagnostic Results" in "TRANSMISSION".
With GST
Follow the procedure "With CONSULT".
Is "P1777" detected?
YES- Go to .
NO- INSPECTION END


Diagnosis Procedure


1. CHECK STEP MOTOR CIRCUIT (PART 1)

1.Turn ignition switch OFF.
2.Disconnect TCM connector.
3.Check resistance between TCM vehicle side harness connector terminals.





Is the inspection result normal?
YES- GO TO 2.
NO- GO TO 3.

2. CHECK STEP MOTOR CIRCUIT (PART 2)

Check resistance between TCM vehicle side harness connector terminals and ground.





Is the inspection result normal?
YES- Check intermittent incident. Intermittent Incident.
NO- GO TO 3.

3. CHECK STEP MOTOR

1.Disconnect CVT unit connector.
2.Check step motor. .
Is the inspection result normal?
YES- GO TO 4.
NO- Step motor is malfunctioning. Replace transaxle assembly. Exploded View.

4. CHECK HARNESS BETWEEN TCM AND CVT UNIT (STEP MOTOR) (PART 1)

Check continuity between TCM vehicle side harness connector terminals and CVT unit vehicle side harness connector terminals.





Is the inspection result normal?
YES- GO TO 5.
NO- Repair or replace damaged parts.

5. CHECK HARNESS BETWEEN TCM AND CVT UNIT (STEP MOTOR) (PART 2)

Check continuity between TCM vehicle side harness connector terminals and ground.





Is the inspection result normal?
YES- Check intermittent incident. Intermittent Incident.
NO- Repair or replace damaged parts.


Component Inspection (Step Motor)


1. CHECK STEP MOTOR (PART 1)

Check resistance between CVT unit harness connector terminals.





Is the inspection result normal?
YES- GO TO 2.
NO- Step motor is malfunctioning. Replace transaxle assembly. Exploded View.

2. CHECK STEP MOTOR (PART 2)

Check resistance between CVT unit connector terminals and ground.





Is the inspection result normal?
YES- INSPECTION END
NO- Step motor is malfunctioning. Replace transaxle assembly. Exploded View.