[robbediagnostics]

I am working on a bmw 114i and the heating control has gone bad, I already tried refitting the whole control unit with another one but i still keep seeing nothing, I can not control the heating? I get one dtc code about the lin-bus connectio and i already tried putting the lin-bus cable on another lin-bus cable but that doesnt help the problem my DTC is 80120F deos someone know this problem?

vin: 634240