Hi all, thanks for this awesome resource. I'm trying to sort out a P0128 code on my 12 Clubman. CEL light came on a few months ago, along with fan running constantly and rough idle. It's now had 2 new thermostat housings, new water pump and, wound up at a good local import shop. They pressure tested it and came back with a bad head gasket. I went ahead and did the head gasket myself, got it back together and it's exactly the same. Same code, same rough idle. I just ordered a new engine coolant temp sensor, but I'm wondering if there's any other thoughts on this. Someone has recommended resetting the adaptations, but I don't have an OBD 2 scanner that can do that. Would love your thoughts on this, thanks.

 

According to https://bmwfault.codes/ its "Coolant temperature sensor, signal: Permanently stuck at low":
https://bmwfault.codes/XMLDiagView?d...cAOAAyADAANAA=

On the N18 engines there was a jumper harness for the coolant temp sensor. It is possible that the temp sensor is bad, but I might think that is a break in the harness of sensor connections.