Loss of power steering

Hello all,i have a strange problem with the steering on my A3 2.0 FSI (2004) .

When starting the car from cold there are no problems and the car runs fine,if however i drive a couple of miles,say to get some petrol,when i go to drive away there are 3 loud beeps and a red steering warning light comes on on the dash.

When the red light is on there is basically no assistance to the steering which is incredibly heavy!

However,if the car is left for about half an hour and started again.the steering is back to normal and is fine.
This problem only occurs after starting the engine after a brief stop and never occurs suddenly whilst actually driving.

The problem started at the end of last winter but disappeared for the spring and summer only to start up again this winter!

Just wondering if anyone has had a similar problem or can offer any advice before i have to take the car to a audi garage.

Just bought a new ross tech micro-can cable (genuine!) and this is what it comes up with:

1 fault found:
01309 - power steering control module (j500)
004 - no signal/communication
freeze frame:
fault status: 01100100
fault prority: 2
fault frequency: 1
reset counter: 168
mileage: 74932 km

I ran another scan about an hour later when i knew the steering would be working and sure enough no fault codes showed up.

I am hoping it is maybe a wiring problem as the fault is intermittent.