[MBZ] 5.0 euro high idle, what controls it

[Kaleb C. Striplin]

As you know the 380SE with the euro 5.0 idles at around 900-1k rpm all 
the time.  I just fired up a full fledged euro 82 500SE that is here for 
the first time in a few months and it idled at 900-1k, then after a few 
minutes it all the sudden clicked down to a normal idle of about 650 or 
so.  So it appears my car is stuck in cold high idle.  What controls 
this function?  Is their some sensor that adjusts the idle after it has 
reached a certain temp?  Maybe this sensor is bad on mine.  Or is their 
some vacuum control that adjusts the time after it has warmed up that 
causes it to idle down?
--
Kaleb C. Striplin/Claremore, OK
 89 560SEL, 87 300SDL, 85 380SE, 85 300D,
 84 250 LWB, 83 300TD, 81 300TD, 81 240D, 81 240D,
 76 450SEL, 76 240D, 76 300D, 74 240D, 69 250
http://www.striplin.net