I have been having a erractic idle issue with my 400E. the car idles at approx. 1500rpm in park and idle bounces every few seconds from 1700rpm down to 1200rpm and everywhere in between(very high). I replaced the wiring harness because it was all to pieces, still had problem. I replaced module 1245453632 the cruise control/ idle module with a used part, this took care of the idle jumping around but now that I have a smooth idle it is still high it stays at a constant 1500rpm in park, drops down to the 700rpm range in drive which that is fine with me. My question is, is there any way to adjust idle, or what parts controls this function on this car. Thanks