CVT RE0F09B

P1778 STEP MOTOR





Description
- 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 operate normally.




DTC Logic

DTC DETECTION LOGIC






DTC CONFIRMATION PROCEDURE

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 RE0F09B.

NOTE:
If "DTC CONFIRMATION PROCEDURE" has been previously performed, always turn ignition switch OFF.
Then wait at least 10 seconds before performing the next test.
1.CHECK DTC DETECTION
With CONSULT-III
1. Turn ignition switch ON.
2. Select "DATA MONITOR".
3. Make sure that output voltage of CVT fluid temperature sensor is within the range below.





4. Start engine and maintain the following conditions for at least 30 consecutive seconds.





With GST
Follow the procedure "With CONSULT-III".
Is "P1778" detected?
YES - Go to CVT RE0F09B.
NO - Check intermittent incident. Refer to Intermittent Incident.




Diagnosis Procedure
1.CHECK STEP MOTOR SYSTEM
Check step motor system. Refer to CVT RE0F09B.
Is the inspection result normal?
YES - GO TO 2.
NO - Repair or replace damaged parts.
2.CHECK PRIMARY SPEED SENSOR SYSTEM
Check primary speed sensor system. Refer to CVT RE0F09B.
Is the inspection result normal?
YES - GO TO 3.
NO - Repair or replace damaged parts.
3.CHECK SECONDARY SPEED SENSOR SYSTEM
Check secondary speed sensor system. Refer to CVT RE0F09B.
Is the inspection result normal?
YES - GO TO 4.
NO - Repair or replace damaged parts.
4.DETECT MALFUNCTIONING ITEMS
Check TCM connector pin terminals for damage or loose connection with harness connector.
Is the inspection result normal?
YES - Replace TCM. Refer to Exploded View.
NO - Repair or replace damaged parts.