1993 Sc300 Shifting Into And Out Of Overdrive At Random

[ryan632]

My sc300 has been having trouble shifting into overdrive. Sometime it will shift just fine, and other times it won't go into overdrive. I just had the capicators in the ECU replaced, and its still doing it. I have also noticed that the spedomoter is off by about 10 MPH, and the tach is off as well. Is it possible that the circuit board is bad. I did a fluid and filter change back in March. The car has 256,000 miles on it. Any advice would be greatly appreciated.

Thanks

Ryan

[Rider3r]

I had the same problem when i first got the car. It is a 95 with 114,xxx miles. i have not found a solution yet i just know it gets worse. I have to manually shift it into first if not it is stuck in third no matter how slow of fast your driving. I've had the trans rebuilt and nothing changed. I am ruining out of things to try and fix it.

[ryan632]

I ended up replacing the ecu with a refurbished one and have not had a problem since.