This is usually caused by the multifunction/headlamp switch. See this thread aurorah.proboards.com/thread/23492 be sure to read through the whole thing including the posts following the initial walk through
The LCM can rarely be the culprit but the MF switch is almost always the root cause. I would at least try cleaning it out and seeing if that helps before replacing the LCM. Not sure if they are available new, but I wouldn't get one anywhere but a salvage yard or else you'll be paying a heft sum. Might try eBay as well.