Elantra L4-18L (2011) A/T - MIL ON/DTC's P0717/P0721/P0722/Stays In 3rd gear - Page 288
13. Remove three bolts to the solenoid valve connector.
14. Pull the solenoid connector outward and move the connector out of position.
15. Remove the bolt that secures the detent spring and remove the spring.