Originally Posted by cn90

Use only BNW reservoir and sensor.
I assumed you checked coolant level?

Yes, checked the coolant level... thinking it's the sensor that attaches to the bottom of the reservoir

For 4x4 light...Check tire P.

The alignment did the trick.... steering wheel now centered and light remains off.

PS: Win Regulator, I use VDO brand.
I used the URO brand on my 2001 E39 530 and liked the rollers...

Thanks for the answers..