Quote Originally Posted by 318 iS Cosmos

It's a joke, simple as. I think there is a warning light but still pretty shoddy from BMW. For example, if you bleed the cooling system, how the hell do you monitor coolant temps afterwards? Or can you do something similar to the E46 and unlock some hidden obc functions?
Here's a wiki, although I've not tried it out. Claims it can give coolant temps from hidden menu: http://e90.wikifoundry.com/page/BC+hidden+menus