Sorry for the lapse in response - we resolved the issue a few days ago. After testing multiple systems we found the oldest problem in diagnostic history - taking the customer's description of how / when the problem presented at face value. The customer told us that the unit failed to operate in the bay where is was charged and had not been moved. Not the case. They had pushed the unit into it's resting place and in turn caused the steering wheels to extend beyond their allowable angle. We manually repositioned the wheels and BINGO. Of course the over steering caused damage to the steer encoder as well as the actuating rod but besides that she's good to go.
Thank you all for your help and ideas. This is the first time that I have posted on this forum but after this experience I will be much more active.