Automatic Trans: Diagnosis: Description

The GF4A-EL is a 4-speed electronically controlled automatic transaxle. Six solenoids control shift changes and shift feel and are located in valve body. Solenoids are controlled by the Powertrain Control Module (PCM).

NOTE: TCC solenoid is also known as lock-up solenoid or TCC lock-up solenoid.

PCM receives information from various input devices. PCM uses this information to control the following solenoids:

Shift Solenoids "A", "B" and "C" for transaxle shifting.
TCC control solenoid for torque converter clutch lock-up.
3-2 timing solenoid to reduce downshift shock.
Pressure Control Solenoid (PCS) to control line pressure.

An Overdrive OFF (O/D OFF) switch is mounted on gearshift lever. When O/D OFF switch is released to ON position, transaxle will shift into 4th gear when gearshift lever is in "D" position. O/D OFF light on combination meter should not be illuminated. When O/D OFF switch is depressed to OFF position, transaxle will not shift into 4th gear and O/D OFF light will be illuminated.