As said Engine harness replace due the dealer broke a harness but don't want to admit this.
So the story is:

One week ago I brought car for thermostat fault ( I did read it), so BMW dealer replaced thermostat, then after I got car back (1.5 day) the light got back again. I read a code it was same thing p0128 Coolant Thermostat (Coolant Temperature Below Thermostat Regulating Temperature). Well after dealer kept car for almost a week they told me it's engine harness.

So I guess these mechanics are pulling connector while holding harness and torn harness a part. It's not a big deal when you have warranty, but if not then it's bad thing we should not pay for this.
So be aware of it, if someone will tell your engine harness (sensors) is suddenly bad, after car was at dealer.