Unknown Powertrain Code on Toyota Tacoma?

I have a 1996 Toyota Tacoma (2 Wheel Drive; Automatic) with V-6 Engine and 130,000 miles. After the Engine light came on I scanned it and got the following code:

"Trouble Code P1700 Unknown Powertrain DTC (Manufacturer Controlled, Transmission)"

I can't seem to find out what this really means. This has gone on for sometime now and I can delete the code but it always comes back. The transmission fluid level is normal and nothing seems to have changed in the performance of the truck. It still runs great. I looked at some of the connectors going to the transmission after removing them but they were fine so I just put them back on. Nothing changed at all. Does anyone know what this code really means and if there is something I can do to correct the Engine light continuing to come on for it? Thanks.