Help with Audi A2 power steering pump failures

The Audi A2 has three different ranges
2002 - 2005 6Q model
2006 - 2009 9N model
2009 - 2013 6R model.
They all use a TRW electro hydraulic power steering pump.
The 6Q and 9N model of A2 use a steering pump whose part numbers are
6Q0423156 AB
6Q0423156 M
6Q0423156 S
6Q0423156 B

The pumps can suffer from a variety of internal electrical failures that will cause the steering pump to stop working and the red steering failure light to illuminate on the dash. Diagnostic scans can sometimes fail as the power steering pump will often stop communicating with the vehicle.
Sometimes a terminal 30 short to ground or excessive current will display on the scan., any of these failures will require the steering pump to be replaced.
The pumps that we supply do not require any coding or programming, although it is important that the correct pump variant is matched to the VIN number of the vehicle which we check before we dispatch the part to you.
It is also important to check the condition of the electrical plug connections as corrosion can build up and cause high resistance.

The later model 2009-2013 use and updated TRW power steering pimp which uses part numbers;
6R0423156 AB
6R0423156 B
6R0423156 C
This pump can be used to replace the earlier 6Q pump if the correct variant is matched.
The 6R steering pumps suffer the same internal failures as the earlier 6Q pumps.
Plug connections are the same on all the pumps with the exceptions of the late 2009 onwards vehicles who only use 2/3 of the connections on the pump with the third connection having a blanking cap fitted. These pumps suit vehicles whose steering rack does not have a motion sensor fitted.