The ICU has a few cables attached to it. Can anyone tell me what they do? The one pin is the CPS i know already. There are two 4 pin plugs on it as well. The forward most looks like it goes to the coil and the rear one looks like it goes near the battery.
Why does the 16 valve 190 have two 4 pin connectors and regular 190e 2.3's have only 1 4 pin connector?

You might want to check out this website.
http://web.archive.org/web/20060602101116/http://mb.braingears.com/201_Chassis.htm

The 190E's with one 4 pin connector use a Transistorized Control Module N1/1. The 190E's with two 4 pin connectors use an Ignition Control Module, N1/2.

My '93 2.3 8v has 2 connectors at the Ignition Control Module, N1/2.

The rear one:
Pin 1, Engine Coolant Temperature Sensor
Pin 2, Wide open throttle/closed throttle position switch
Pin 3, Reference Resistor (on my car it is a cable harness with a resister plugged into it with tape around it, it's located near the ICV under the breather...came from the factory like that)
Pin 4, Vacant (lead ends in wiring harness or intake air temperature sensor)

The front one:
Pin 15, Terminal 15
Pin 16, Ignition coil terminal 1
Pin TD, TD signal
Pin 31, Ground

Note, the pin numbers appear on top of the connectors.

__________________

1993 190E 2.3
2001 SLK230
1971 LS5 (454) Corvette Convertible

The N1/2 unit is for the EZL ignition cars, is that correct? Is the module the same for 4 cyl vs the 6 cyl cars as well?

Pretty much all cars with diff engine have diff Control Unit. Some times even diff years do. For sure the 190E 4 cyl EZL will not be proper for the 6cyl and the 16v EZL is specific to the 16v, unfortunately...they get real expensive, new are over $1000, really.
The plug and cableon the 16v EZL to the coil is about $55, but get this..the plug and harness from the other connection to the sensors is $1000 plus change...really! I priced it cause my plug at teh EZL is deteriorating. To say the least, it is still not replaced! I am still looking for a decent spare 16v EZL to hold on to. Running about $100 to $200 used, but getting hard to find.

__________________
Christopher Henkel
1990 190E 2.6 - Arctic white SOLD
1986 190E-16v - Blauswartze
1993 300CE - SOLD
2003 W208 CLK 320 Cabriolet - Magma Red