Mitsubishi: transaxle, eclipse gsx, transmission shop

Question
i have a 1991 eclipse gsx two door hatch.it has the 2.0 turbo in it.i was driving down to my friends house the other day and all of sudden the car just downshifted like it lost overdrive.the car has 84,000 miles on it.the engine was hot.there is no diagnostic trouble codes.i was doing 45 mlies per hour when this happened.i changed the fluid and the filter but it made no difference.

Answer
Hi Ed,

Changing the fluid, if you read my previous posts, will do more harm than good. If there are no codes then you need to have your car towed to the nearest transmission shop for an overhaul. I suspect, after 11 years in the transmission field and if what you told me here is correct, there is likely a DTC and the transmission just needs a sensor, solenoid or switch. Your transmission went into failsafe, which is the down shift, because the computer saw a problem, setting a DTC and giving you second and reverse only. Even at 100 MPH, when the computer sees an issue, it will through you into 2nd. I suggest you take your car to a transmission shop and have it scanned. A Cottman Transmission Shop will do this for free.