Did M103 engines have idle speed control integrated into the ECU, thru a separate control module, or were either/both used in different chassis?
If there is a separate module for some applications, what is/are the part number(s)?

Looking at a W126 wiring diagram for the M103 motor the idle air control valve is controlled by:


-1989 and older cis ecu and ovp relay
-1990 and newer just cis ecu

The M116 and M117 motors have a separate idle module for that.

Thanks ct; if similar info for the 201 & 124 applications is available it would be appreciated.
The objective is to run an idle air valve controlled by a stand-alone module that correctly recognizes a six-cylinder TD frequency.

Just looked at the W124 wiring for M103 motors and both 3.0 and 2.6 do it like in a w126


why do you need a stand alone module?