Transmission Does Not Shift Into Overdrive On Level Road (4-Speed A/T)

If transmission does not shift into overdrive on level road on vehicles equipped with 4-speed A/T, perform the following procedures in order:

• Perform THROTTLE VALVE OPENING SIGNAL CIRCUIT CHECK  under SYSTEM TESTS.
• Perform OVERDRIVE & TCC OFF COMMAND SIGNAL CIRCUIT CHECK  under SYSTEM TESTS.
• Replace actuator with known-good unit. See ACTUATOR ASSEMBLY  under REMOVAL & INSTALLATION.