Probably the engine CTS, check the suggestions in this link.
I'm suspecting the thermostat at this point. Watched the measuring block for G62, the instrument gauge came up to 190F but the measuring block never got above 75C.That light also gets set for it not coming to temp as quickly as the ECU expects. Such as with a stuck open thermostat. Really noticeable in cold weather.
Thanks for the input @cuppie & @Tomvw . Ended up being the Thermostat was not closing all the way, kept the engine from coming up to temp, held mostly at 75C.To expand on Tom's last post:
The reason that he wants you to verify the temperature data via measuring blocks in the instrument cluster (not just by looking at the temp gauge), is that there's a 'flat spot' in the temperature gauge - from (about) 182-207F (83-97C), it points right at 190F. The logic is that 'drivers might freak out over the normal minor fluctuations in the engine temperature, therefore, we're going to hide that from the driver.'