Hello Folks, very glad to have found this forum and I need your kind help on attacking this high idle issue.

Car: 1991 560 SEL with 103000 miles
Problem: idle at 1400 in P and 900 in D.
Action so far: measured idle control valve and get 4.8 ohms and 3.2 V with car running. That give me about 670 ma of current which is too low. I read that the current should be between 750 to 1000 ma.

Based on my search, there are 5 more items to check: OVP, ICU, Throttle switch, vacuum leak and injectors.

Since I don't have any warning lights on nor any problem starting the car, I don't think it is OVP. My next action is to check out the idle control unit. I already took the unit out and could not find any visiable burn or loose connection. It is such a small unit and I don't think I could bent it or flex it as some posts suggested.

Questions to experts: !) is there any way I could use my DMM to measure something on ICU to find out if it is bad?
2) I also read that the throttle position switch is near the cold start injector which is next to ICV. I read that one could measure if it sticks to the open position. Could you please let me know how to do that?