mechanic recently ran codes and found brake controller to be faulty. he noted that this year S80 often gave false error messages, but noted that this brake controller would adversly affect the traction control system. this is the 5 th volvo my wife and i have owned and is by far the worst!!! most problems were covered under the extended warranty, however, now we are beyond that and it seems it is always in the shop. now the brake controller is an estimated $850 (us$) repair. what do you guys know about this problem and this model year? is this problem ligitmate or a computer problem?