Boston Driver

I met a "new" owner of a 1999 A6 2.8 with 221k on the odometer recently. Helped with the throttle body adaptation, but the car has an odd shift when driving. It will seem to rev a bit higher between shifts (like the car is in neutral for a second), then slam into the next gear. We tried the tranny adaptation several times (manually and with the VAG COM), but no change in behavior.

The only error code that comes up is:
00526 - Brake Light Switch - F
27-00 Implausable Signal

Thoughts? Bad tranny??? TIA for any thoughts.

paulroad

my first thought is tranny fluid.. not just level, but age.

4Driver4

Low fluid. Almost always.