2010 Nissan Sentra – Power Steering

Hi everybody,
I am trying to help out a coworker with a Power steering issue. I haven’t driven the car but this is what I am told.
“It drives fine until you turn and hit a bump like a Pot Hole, you can’t bring the car out of the turn until you come to a stop and then straighten the wheel, This happens when making right turns.”
The coworker brought this to my attention after taking it to a Nissan dealer (it is out of bumper to bumper warranty).
The dealer replaced a right control arm and shock for around $790.
The car continued to do the same thing (get stuck in a turn after bumps in the road)
Next it went back to the dealer where a steering rack was installed, the dealer didn’t charge for labor. Now The dealer is telling them, “it is better, but it still has the problem, you need a new electronic assist motor, which is part of the steering column, and it costs $1900, there is no way to diagnose the motor, you just have to replace it and see if it works.” The dealer also thinks the electronic assist aided in damaging the rack.

I seem to think you can diagnose anything if you know how. I’m guessing you could set it up with a scope and watch the waveforms for glitches when the problem occurs.

The car cost them $10k and now they are thinking about getting rid of it. what are your thoughts?

Thanks,
Nate