1545 error coding
 

Hi, first post.
Done a lot of research on this on this forum. My 99 a6 2.7 has a slight battery drain, resulting in me unplugging the ground cable at the battery each night. That allowed me to procrastinate for a month. Now it looks like I have a throttle adaptation problem, resulting in the 1545 code. Attempted to clear with licensed VCDS.
Here's what I get:
{select}, {01 engine}, {measuring blocks 08}, enter group 098, hit {go}, {switch to basic settings}. top right says ADP OK, wait to cycle and last command is {switch to measure blocks} at this point the ADP OK section now says "error".
I'm thinking bad throttle position sensor. Is there an ohm test I could perform going through the range of motion?
Really could use some help from the Audi wizards.
Thanks, Sean

Or if anyone could direct me to a link that would show the breakdown of a throttle body? Thanks any help is appreciated.