Bad news... the light came back on.
1. Drove into Partsource and had them run a OBD-II scan. (FYI - it is free)
2. Checked the code: P1553
3. BMW FC Code: 2A99 [Engine Position System 'B' Performance (Bank1)]
4. Searched the internet... seems to be related to the following...
a) Camshaft Sensors (2x in total for E90, intake and exhaust)
b) VANOS Solenoids (2x in total for E90, intake and exhaust)
Now, from what I am reading, "dirty" VANOS Solenoids can cause fault codes for the Camshaft Sensors. It was noted from BMW bulletin that it should be clean using "air hose" and then reinstall. Other users on the internet seem to be confirming similar treatment when they brought it into the dealer.
1. Take the cheap route first... I will try and clean the solenoids this Saturday. Hopefully that would fix it.
Good news is... the parts are not too expensive and it looks like a DIY'er.
I will update for those interested.