Replaced thermostat housing - faults still showing

[scottmckee246]

A few months ago my check coolant light came on and I found it to be below low level, topped it up and no issues until it happened a few weeks later this time with engine management light on. Scanned the code and found P268100 Engine coolant bypass valve circuit/open. 

Took it to a specialist who replaced the thermostat housing/water pump, old one was full of coolant in the control side.He rewired it and replaced electrical connections. After putting car back together the fault will not clear and some others have shown up - 
P268100 Engine coolant bypass valve circuit/open.
P218100 cooling system performance 
P011600 coolant temp sensor 1 circuit range/performance. 

Car seems to be driving fine only issues are the stop/start is not working, the engine fans are on almost always and ramping up high at low temps, coolant temp/engine oil temp taking a long time to get to temp - over half an hour driving to read engine temps above 90C. No issues with heating/AC.

Worried the leaking system has caused an issue with the ECU but at my wits end trying to diagnose. Any advice is massively appreciated