Transmission Troubles

[mkb]

Hey Folks!

Got another issue with my 99 A6 28qa.

Looks like transmission troubles.  When I go from park to reverse, there is loud a thump and sometimes reverse wont engage.  Going from park or reverse to drive, I get the same loud thump.  When I'm in drive, the transmission wont go out of first gear.  Looks like it's in limp mode.

I was able to pull the following codes:

00688 - Supply Voltage Terminal 30
            31-00 - Open or Short to ground
01236 - Shift Selector Locking Solenoid (N110)
            31-10 - Open or Short to Ground - Intermittent

Any ideas what I need to look at to get started on this???

Thanks much.

--
mohammed
99 a6 28qa
97 a4 18tqa