96 Deville tranny

My 96 Deville does not downshift into first gear. When i take off from a stop it starts in second. The tranny shifts fine through the gears. The service transmission light is on. Anyone have an idea what causes this? I have put over 10,000 miles on the car and it still runs fine other then starting in second, but I'm sure there is more stress on the tranny., thanx

Sure, get it scanned for the trans code and post back, no other way here.

Drain the transmission fluid by removing the rubber plug located near the right rear corner of the pan. Next use a 10mm socket with a short extension and a ratchet to remove the trans pan bolts. Unplug the three electrical connectors with a small screw driver making sure to note where they reconnect at, as two of the three are identical yet they have different locations. Unclip the metal retainer fastened to the skinny rod. Unhook the rod out of it's receptical. Use the socket-extension-ratchet tool set up to remove the valve body assembly (it is a 2 piece unit). Replace the valve body with a good one. This task is so simple, a caveman can do it.

Drain the transmission fluid by removing the rubber plug located near the right rear corner of the pan. Next use a 10mm socket with a short extension and a ratchet to remove the trans pan bolts. Unplug the three electrical connectors with a small screw driver making sure to note where they reconnect at, as two of the three are identical yet they have different locations. Unclip the metal retainer fastened to the skinny rod. Unhook the rod out of it's receptical. Use the socket-extension-ratchet tool set up to remove the valve body assembly (it is a 2 piece unit). Replace the valve body with a good one. This task is so simple, a caveman can do it.

How did you come up with this diagnosis with no way to check it first, btw the solenoid pack could be the issue here, then what? It is in the side cover of the trans, different operation.

True, however the solenoid pack would cause multiple issues if it were bad. And I just happened to repair this same malfunction on a Sedan Deville with the 4T80E transmission.