P1776 solenoid switch valve latched in LR position, anybody familiar with this code?
Any help would be greatly appreciated.
I assume that you find the transmissions sticks in 2nd gear and won't shift out, correct?
The 1776 says the low/reverse pressure switch (located in the solenoid box on the front side of the transmission )is closed when it shouldn't be. Often the first thing that is tried is to replace the entire solenoid pack, but I would look at a couple of less expensive options first.
Another possible causes for the 1776 is that the transmission control relay or its circuit is weak or open (it is located in the power distribution box under the hood on the driver side). You could try switching it with another relay of the same part number in the box to see if the problem changes, and if not then the relay is OK. Check fuse Q in the same box to be sure it doesn't have a crack in its wire.
The transmission control module (computer for the transmission) could be bad but that would probably also cause a code in addition to the 1776. That would be something to do last. Have you checked again for whether you may have new codes?
Also try shaking the wire harnesses to the transmission that come from the controller to see if that affects the problem as it could be a loose or shorted wire in the harness.
Those are the best ideas, unless you have another new code.
The dark green wire for the L/R pressure switch connects pin 2 of the 8-pin plug at the transmission to pin 50 of the trans computer so you could check to see if it is shorted to ground or intermittent connection.