1. Car went in for new rear pads.
2. When local indpendent garage hooked up Bosch KTS570 diagnostics to be able to reset parking brake settings it was unable to communicate with the EPU. "Check parking brake system" warning came on. Parking brake no longer releases on letting out clutch - must me manually released.
3. Took car to Toyota main dealer for pads, TMD unable to reset "Check parking brake system" warning".
4. Codes C1346 ("zero point calibration of clutch stroke sensor undone") and C1336 ("zero point calibration of sensor undone") showing on Toyota diagnostic system.
5. TMD diagnoses parking brake ECU fault (c.£750 + tax + fitting)
Questions: how could hooking up Bosch diagnostic system that could not access brake ECU apparently cause a fault on ECU? Is there any subcompontentry that can be replaced short of full ECU? Has anyone come across anything like this before, and if so, what can be done short of full ECU replacement?