DRS now completely fixed, it was the DRS ECU.
I looked at the mechanics of the Steering rack, very simple, very robust, would be supprised if this was to fail so assumed it wasn't the failure point.
My orignal fault code was "C1241 Low Power Supply Voltage Malfunction (Presumed due to the previous Low battery) which I replaced, I had to jump start the car at this point.
Then I got a new error C1B17.
On Tis, if the ECU reports "C1B17 Motor Rotation Angle Mismatch (Stroke Sensor)" it says replace the rack, this obviously assumed the ECU is not defective. This was my original fault after
I noticed on the live data I had no supply perminent 12v supply to the PIG Power Supply, The ECU was reporting 0.46v but should be between 11 and 14v, I measured the Feed and it was 12v, so the ECU was not seeing this.
My Brother who is an electronics genius disassembled the ECU up to a point and noticed lots of "Dry Joints" soldered them up, reinstalled and the ECU was then reporting 12v. BINGO! Note that the ECU is servicible but lots and lots of pins will need to be desoldered, luckly for me I didn't have to go down this path, note the following link which shows a similar ECU used in the Toyota Camry -
Russian Site with Disassembled ECU
I now needed to test the steering and set the Neutral Position and Calibrate the actuatior (I had previously reset this), note jacking point to do this in picbelow, chock the front wheels!
If you follow the steps in Techstream to memorize neutral and calibrate the rear steering it won't work because Techstream is wrong (or at least my version is 16.00.020), you need to cycle the ignition on and off between steps to presumably put the ECU in programming mode, once done the rear ECU actuated the steering, store the callibration and everything was back to normal.
I have attached all the information to this post in the event it helps someone.
Usefull Links -
Online Wiring Diagrams
Russian Repair Manual (use translation in browser)
Live Data List Printing(S821-03.pdf WIRING - DRS-RHD-B.pdf DYNAMIC REAR STEERING SYSTEM FREEZE FRAME DATA.pdf DYNAMIC REAR STEERING SYSTEM FAIL SAFE.pdf DYNAMIC REAR STEERING SYSTEM SYSTEM DESCRIPTION.pdf DYNAMIC REAR STEERING SYSTEM TERMINALS OF ECU.pdf