2006 A6 Avant 3.2- Filled the gas tank one night, next day would not start. Msg in center of dash reads: "Shift to P, otherwise vehicle can roll away. Doors do not lock if lever is not in P." It is in "P" Removed center console (oh joy) and tested the Neutral safety switch, engages when 12v are applied seems to be ok. Checked for voltage to the wire feeding the switch, none. Replaced brake switch, same thing. Disconnected battery and re-connected, no change. Bought new battery, no change. Bought new laptop and VAG-Com software, does not see vehicle, tried my OBD unit which I've had connected many times to this car, nope, notta. I seem to have no accessory power using the key or start/stop switch. Hard to get a diagnosis when you can't see inside. Where to now?

To answer my own question: Found this little tidbit out on the web; For this vehicle to get accessory power 1) step and hold down the brake pedal 2) turn on emergency flashers 3) turn on bright lights or hold 'flash to pass' brights, this will give acc. power and allow for a partial diagnostics while using VAG-Com.