What is this thing!?

We heard an awful buzzing sound coming from under the dash where the steering wheel is. It came on intermittently but we started to notice a correlation between the using signals and also hitting a bump in the road triggering it. Anyway, we removed the panels below the steering wheel and found a little gray box that looks like a circuit breaker sort of just above a box named "Combination Flasher." This is the culprit. We disconnected it and it stopped buzzing. We checked the flashers, signals, radio, etc., and everything seems to work. So what does this box control!? I'm afraid to put it back together and start driving again until I know! Any ideas? There is a number on the side of the unit--actually there are two--they are 12177235 and on the other side is N9313. The manufacturer appears to be Omron. I'd love to find out what this thing controls.

Thanks!

By the way, it's a 2000 Regal GS

It looks like you found the relay to operate one of the following items. Which one does not operate with the relay removed?
Part #: 12177235 description: relay
Categories:
Mechanical > group 17 - body electrical > horn & wipers
Mechanical > group 2 - fuel & exhaust > fuel supply system
Mechanical > group 5 - cooling > cooling system
Mechanical > group 6 - brakes & wheels > anti-lock brake system

Just a guess and from what I see based on the GM Regal FSM most likely the electronic brake control relay (part of ABS system). The annotation for location says left side of dash right below the Instrument Panel (IP).

Based on the Omron part number that is a standard relay used by GM on many models. I've seen it used in ignition control circuits as the crank relay. When I replaced an ignition switch I saw the relay along with the flasher/turn signal relay but never encountered a problem with it specifically. It is energized by the EBTCM module (electronic brake and traction control) and the ignition switch must be to run. As Enable Relay Output. In turn it passes 12 volts at the NC/NO relay contacts to the ABS fuse and subsequently to the ABS motorpack and solenoids. The 12 volts at one side of the relay contacts is hot at all times (direct off battery supply) so that may explain the weird symptoms seen.

It must be the ABS since everything else mentioned appears to be working fine. I guess I can order the part from GM using the part number, but how difficult would you rate changing it out?

Thanks, again!!

You might have difficulty locating part # 12177235. I think it might have been superseded by 12177233, or it is being used as a replacement for that part#where it isn't available. I'm trying to remember an incident awhile back where we had trouble getting that first part and we ended up using the 233 as a replacement. If you can't get the 235 number, ask if the 233 will work in it's place.

UPDATE - we replaced the part, 12.99 at our local auto parts store, and now it is working like normal. Thanks for the help, everyone!