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.
Valve body spacer plate or gaskets damaged or not positioned correctly | Inspect the valve body.
Throttle valve is binding or sticking | Inspect the valve body.
Check balls omitted or not positioned correctly | Inspect the valve body.
Internal damage to torque converter | Replace the torque converter.
Direct clutch piston or seal leaking or damaged | Inspect the direct clutch piston and seal.
Incorrect fluid pressure | Perform the line pressure diagnosis.