Green light comes on when cruise control activated, but does not work when commanded to set vehicle speed. No codes, no idiot lights. No other known issues on the car currently.

Brief system overview in Bentley, nothing in Haynes; zero troubleshooting go-by at this point.

Guessing could be switch on steering wheel / clutch switch / brakelight switch / throttle body / ECM. Just wondering if anyone else had this issue, how they solved it / what might be most likely to check. Trying to avoid Easter-egging it. Any help appreciated thanks.

 

Check the clutch switch located on clutch pedal.

 

Yep, and if you have inpa I believe you can use it to confirm the + button works as well as clutch switch and brake switch.

I haven’t dug in but usually the bmw brake is always a 4 wire, two circuits… one for lights and the other cruise.

also on cars with a failed abs sensor (both my 04 and 05)I’ve noticed it may take 2-3 attempts before it lets you enter cruise the first time.