2010 with buzzing brake pedal while stopped

Greetings all. Purchased a used 2010 Gen III a few months ago and have noticed a fast buzz, felt through the floor and brake pedal. It is intermittent but the conditions needed are:
1) Air conditioning running at high speed
2) Vehicle in Drive
3) Immediately approaching a stop, and a few seconds after stopping.

It is definitely not the brake accumulator running. This is a much higher frequency buzz. If the A/C is turned off, or the vehicle shifted to neutral, the buzzing stops. I cannot necessarily feel it while driving as it would be covered by road vibration, but it comes on heaviest just as the vehicle is stopped and lasts for a few seconds then seems to phase in and out.

Anyone else experience this?

 

Update/resolution: It is a known issue! Just took Elsa to the dealer today and described the problem as I have here. When I got her back the advisor said they updated the brake and ABS software to a newer version and it should greatly dampen, but not eliminate the noise. Drove 30 miles this afternoon and didn't notice it at all, so I'd call it a success.

My service invoice reads:
"EL1034 REFLASH BRAKE ACTUATOR SKID CONTROL ECU"
"Noise caused by brake accumulator building pressure. EL1034 recalibrate ABS ECU with updated software to reduce brake noise"

The only thing that confuses me is the noise itself wasn't coming from the accumulator. When it would make the noise I pumped the brakes to try to isolate the noise, but while I heard/felt the buzzing I also heard the accumulator activate to recharge the brakes from the pumping.

But alas, no more noise. Hope this helps!