2015 MS70D parking brake, one side does not work at all. After checking that pads (new last fall) were clean and free to move and that the cable appeared intact, I measured incoming voltage to the motor and found that it was unchanged at moving from or to Park. For some reason it was staying at 4v. Any guidance as to where to check, or whether an owner can deal with this at all? Is it a fault of the EPB ECU? Are both left and right side voltages sent in parallel? Is that control unit accessible to mortals? This seems to be a problem not yet discussed, although it's hard to believe that any problem is new!