Matt,

My take on it is if you disconnect the ICV and idle doesn't increase to nearly 2K rpms, you have a problem with the ICV. Or if it increases but returns to the prior idle slowly, you have a problem.

No idea on how to check the control unit. Someone posted a decent "how-to" on ICV disassembly and cleaning. Might be worth a try at the very least.

EDIT: Just though of this as I hit the submit...double check every connection for possibly vacuum leaks, they could cause a slightly high idle.

__________________
Mike Tangas
'73 280SEL 4.5 (9/72)- RIP
Only 8,173 units built from 5/71 thru 11/72

'02 CLK320 Cabriolet - wifey's mid-life crisis

2012 VW Jetta Sportwagon TDI...at least its a diesel

Non illegitemae carborundum.