Photonica

2000 A8
OBD2 code P0322
Ignition / Distributor
Engine Speed Input Circuit
No Signal
It will run for half a second upon start up, then nothing. Any help would be appreciated

90SQ

Crank sensor.

BrianC72gt

Yup , Crank Sensor, I think Audi calls it Engine Speed Sensor G28? The ECU relies on the engine speed sensor to tell if the engine is running. If the sensor is dead, the ECU will cut fuel and engine dies. Does your tach show engine RPMs. It mounts on the top of the transmission at the back of the engine bay. When you first turn the key, the fuel pump runs briefly then stops. You crank it over, engine starts, and the rpms jump up over cranking speed. The ECU, sensing the engine speed increase, decides that the engine has started and allows the fuel pump and the injectors to keep running.

So, that would be a good guess.

Also,check for a wet ECU under the hood in the engine electrics box in the well by the firewall.

Regards,

Brian