2001 Mercury Sable P1779, P1000, Speedometer, Tachometer

With this cold weather I have been having some issues. When the temperature outside dropped to near 0°F I had a check transaxle light illuminate on my dashboard. The specific engine code reads P1779. I have done some research and found that it could mean a variety of things. I have listed them below. However, I believe this is an electrical issue as I have not had any hard shifting or signs of errors in the transmission. My gas mileage continues to be normal. I checked the transmission fluid level and it is full. This code has been on since 1/11/14. Just recently, my speedometer and tachometer stop working until the engine stays warms for about 15 minutes and heats the cabin. I have driven the car with no heat on in the interior and the gages stay off. During this time the check transaxle light and the code P1779 do not illuminate or read when I check the engine codes. With these issues I purchased a code reader and I also found that there is a P1000 code. This P1000 code continues to read even when the P1779 code does not. With this same code reader (iPhone app DashCommander) I can still rerad RPM and speed when the gages are not working. This further leads me to think it is an electrical issue.

Any help with this issue would be much appreciated.

P1779 Defined:
1. Transmission control indicator light circuit
2. Engine Torque Delivered To TCM Signal
3. Solenoids in transmission could be malfunctioning
4. Low transmission fluid

P1000 Defined:
1. OBD system readiness test not complete

Transmission History:
Transmission fluid and filter have been changed aproximatly every 30,000 miles
Timeline of events:
1/11/14 Check transaxle light illuminates
1/25/14 Speedometer, tachometer, and check transaxle light stop working until car warms up
1/27/14 P1000 code found

Car information:
2001 Mercury Sable LS
179,000 miles
Engine is regular 3.0L (not DOHC)
Transmission type is AX4S
Oil changed every 5-7k miles