1. Remove the control valve body. (See CONTROL VALVE BODY REMOVAL/INSTALLATION [GF4AX-EL].)
2. Remove the solenoid valve(s).
3. Apply ATF to a new O-ring and install it on the solenoid valve.
4. Install the solenoid valve in the control valve body.
5. Install the control valve body. (See CONTROL VALVE BODY REMOVAL/INSTALLATION [GF4AX-EL].)
6. Add the ATF while the engine is idling, and inspect the ATF level and leakage. (See AUTOMATIC TRANSAXLE FLUID (ATF) REPLACEMENT [GF4AX-EL].)(See Automatic Transaxle Fluid (ATF) Level Inspection.)
7. Perform the time lag test and line pressure test. (See MECHANICAL SYSTEM TEST [GF4AX-EL].)