Cadillac Repair: Code E39, fuel mileage, electronic problem

Question
I have an 89 Coupe Deville FWD and I get the code E39. But the car works great and there is now decrease in torque when I hit 55mph. Sometimes the service engine light goes on and other times it doesn't. I am planning on traveling 4000km and I'm wondering if the car is safe to take the risk or is this just an electronic problem. The Car have 112000miles on it it runs great never had any major problems.

Answer
E39 means that your overdrive in the transmission is not working which will greatly effect your fuel mileage.

The most common fault is the TORQUE CONVERTER SOLENOID that is faulty.

I can e-mail you a picture location of the solenoid and a simple test procedure if you e-mail me at: onlineautohelp@msn.com