For 1990-2009 cars

Problem | Action
--- | ---
Low fluid level | Add fluid.
Throttle valve cable out of adjustment, binding or damaged | Adjust or replace the throttle valve cable.
Throttle valve binding or sticking | Inspect the valve body.
1-2 shift valve binding or sticking | Inspect the valve body.
Primary regulator valve binding or sticking | Inspect the valve body.
Intermediate servo seals are cut or damaged | Inspect the valve body.
Intermediate servo piston is binding or sticking | Inspect the intermediate servo seals.
Intermediate servo piston rod is not engaged | Inspect the intermediate servo piston.
2nd brake band is worn or out of alignment | Inspect the 2nd brake band.
Internal damage to torque converter | Replace the torque converter.
Forward clutch discs are worn | Replace the forward clutch discs.
Forward clutch piston or seal are leaking or damaged | Inspect the forward clutch piston and seal.
Input shaft O-rings are cut or damaged | Inspect the input shaft O-rings.
Fluid pressure is incorrect | Perform the line pressure diagnosis.