The wheelchair service technicians could not find the source of the problem that caused the chair to only turn in circles, however, they believed the brake within one motor was not releasing. If you recall from previous posts, both motors failed and had to be replaced a few months ago. They are both new motors!
My service technician called Permobil U.S. in Tennessee, the nearest large distributor of the wheelchairs. (I believe the U.S. Permobil headquarters is in Texas) Permobil U.S. was less than helpful as they kept asking my technician for the error code. There was no error code displayed - if their was, the problem would be evident and there would be no need to call! Permobil in Tennessee just didn't get it and offered no solution.
So, although I've used the chair for just over two weeks with no further problems, the original problem was not found or resolved. So, I use this chair with little confidence, not knowing if or when the problem may show up again. I am in a Permobil wheelchair and I have no confidence in it getting me to where I am going. What a fine product!