A typical replacement is Part # 5N0965561A that runs $530 from VAG Australia (Pierburg or Buehler) with another $126 labour and $132 for G13 coolant. Alternatively, get a $70 cheapie like the BAPMIC on eBay (risky, error code may not clear, or part may fail prematurely).
Pros: cheaper alternative available
Cons: risky, may fail prematurely
Vehicle:
Volkswagen Golf
Part number: 5N0965561A