My Girlfriend has an 02 Protege 2.0 L and her overdrive button doesn't work anymore, the light on the dash doesn't turn on and I have a feeling that the engine is stuck in D rather then O/D. I don't know much about these cars but it seem to rev pretty high at highways speeds (120km), around 3500 RPM. Can anyone tell me if there's a simple fix for this problem and what the RPM should read when at highway speeds, thanks for your help.