I too had the two beep alarm last week. Engine ran fine but when I looked at the IAC it had melted plastic on the connector. Replaced it with new IAC and gasket all is good now.

Had the exact issue with my 525 efi last month but symptoms were slightly different. Would get a quick beep at about 3100 rpm, drop below 3000 and nothing, same above 3200. We scanned it with a Rinda but no codes show up. Also noticed the motor would cutout for a split second while idling in gear occasionally, last issue was when shifting from gear to neutral it would rev up for an instance occasionally maybe 1200-1500 rpm.
Since it was only at 3100 rpm I ran for a couple weeks until my shop had time to look at it.
They found that at about 3000rpm on the scanner it was getting a neutral signal, replaced the $35 switch and solved the problem.
[ATTACH=CONFIG]558075[/ATTACH]Hope this helps anyone with similar symptoms.

It is the switch with the purple wires.