TPMO system failure '07 430

I have an orange "SERVICE" light on the dash for the third time in one year. You cannot recalibrate with the button under the dash with this failure. It was fixed the first time with a new ECU. The problem returned two months later. This was fixed again at the dealership with a reset by unpugging and replugging the ecu, thus resetting it. Three weeks later same problem. The manual shows a vague picture of the TPMO ecu in the front driver side wheel well. So my question is this approached from the wheel well by taking off the wheel, bonnett, or in car under the dash? Will turning the master battery switch off reset it?

Thanks for any help.