P1777

P1777 STEP MOTOR





Description
The step motor changes the step by 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.




DTC Logic

DTC DETECTION LOGIC






DTC CONFIRMATION PROCEDURE

CAUTION:
Always drive vehicle at a safe speed.

NOTE:
Immediately after performing any "DTC CONFIRMATION PROCEDURE", always turn ignition switch OFF.
Then wait at least 10 seconds before performing the next test.
1.CHECK DTC DETECTION
With CONSULT-III
1. Start engine.
2. Drive vehicle for at least 5 consecutive seconds.
3. Perform "Self Diagnostic Results" in "TRANSMISSION".
With GST
Follow the procedure "With CONSULT-III".
Is "P1777" detected?
YES - Go to P1777.
NO - Check intermittent incident. Intermittent Incident.




Diagnosis Procedure
Regarding Wiring Diagram information, [1][2]Electrical Diagrams.
1.CHECK STEP MOTOR CIRCUIT





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










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





Is the inspection result normal?
YES - GO TO 5.
NO - GO TO 2.
2.CHECK HARNESS BETWEEN TCM AND CVT UNIT (STEP MOTOR) (PART 1)





1. Disconnect CVT unit connector.
2. 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 3.
NO - Repair or replace damaged parts.
3.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 - GO TO 4.
NO - Repair or replace damaged parts.
4.CHECK STEP MOTOR
Check step motor. P1777.
Is the inspection result normal?
YES - GO TO 5.
NO - Replace transaxle assembly. Exploded View.
5.DETECT MALFUNCTIONING ITEMS
Check TCM connector pin terminals for damage or loose connection with harness connector.
Is the inspection result normal?
YES - Replace TCM. Exploded View.
NO - Repair or replace damaged parts.




Component Inspection (Step Motor)
1.CHECK STEP MOTOR





1. Check resistance between CVT unit connector terminals.










2. Check resistance between CVT unit connector terminals and ground.





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