DTC P0740 (Flash Code 40): Lock-Up Control System
WARNING: This page is about a different variant/trim than selected.
NOTE:
Do NOT perform this DTC test until all other DTCs have been repaired first.
- Using scan tool, check for any other DTCs. If any other DTCs exist, repair those DTCs first, then recheck for DTC P0740 (FLASH CODE 40). If no other DTCs exist, go to next step.
- Test line pressure. See HYDRAULIC PRESSURE TEST under TESTING in TRANSMISSIONS OVERHAUL - A/T article. If clutch pressure is within specification, go to next step. If line pressure is not within specification, repair hydraulic system as necessary. See HYDRAULIC PRESSURE TROUBLE SHOOTING table under HYDRAULIC PRESSURE TEST in TRANSMISSIONS OVERHAUL - A/T article.
- Test clutch pressure. If clutch pressure is within specification, go to next step. If clutch pressure is not within specification, repair hydraulic system as necessary. See HYDRAULIC PRESSURE TROUBLE SHOOTING table under HYDRAULIC PRESSURE TEST in TRANSMISSIONS OVERHAUL - A/T article.
- Replace lock-up control solenoid valve assembly. See LOCK-UP CONTROL SOLENOID VALVES under REMOVAL & INSTALLATION. Turn ignition off and clear codes. See CLEARING CODES . Road test vehicle at over 50 MPH for more than one minute. Recheck DTCs. If P0740 (FLASH CODE 40) returns, go to next step. If P0740 (FLASH CODE 40) does not return, system is okay.
- Replace torque converter. Turn ignition off and clear codes. See CLEARING CODES . Road test vehicle at over 50 MPH for more than one minute. Recheck DTCs. If P0740 (FLASH CODE 40) returns, replace transaxle. If P0740 (FLASH CODE 40) does not return, system is okay.