Re: V8 Quattro Error Codes

I'm in agreement with Bastian about checking and cleaning connections. The throttle pot has a wide (6pin?) connector, and is prone to water damage if the rubber boot on the connector is damaged. It's at the front of the engine. It's fairly easy to access and clean the contacts of the connector, but the unit is sealed.

The gearbox speed sensor and the O2 sensor are also able to get a bad connection due to a build up of grime. The O2 especially if there is even a small oil leak at the rear of the engine.
In both case, disconnecting, cleaning off and then drying the connections afterwards may help you.