I tried disconecting the icv connector with car running at op temp and my idle went way down! I thought it was going to stall.
I always test mine after cleaning it by hooking it to 12 volts to ck the operation.I like to see it goes full travel I found a bad one doing that test.
Is it normal for the idle to drop?? although mine does I am having alot of problems lately!.......................What symptoms are you having that you are looking at the ICV???

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88 W124 3.0
96 R129 119eng
06 ML350
98 ML320 sold
02 CLK55 amg