Still working on my 1988 300 SE. Someone sent me a copy of 073-121 Testing electrical components of CIS-E injection system. In this write up the control system still shows a 25 pin connector used at the control unit N3.


The 1988 300SE does not have a N3 control unit. The N3 function has, as far as I can find, has been incorporated into the computer module. The computer module is connected with a 35 pin connector. Does anyone have access to a pin out sheet for this 35 pin computer connection?

Component N3 on the wiring diagrams IS the KE-Jetronic (CIS-E) "computer module". It is the central controller for the KE system, and all versions have a 25-pin connection. A connector with 35 pins is used with the Motronic systems.
A picture, showing the pins/sockets, of the connector that you are dealing with would probably be helpful for all parties.

What I have in hand is a MB computer module labeled 005 545 21 32. I removed it from my 1988 300 SE. It has a 35 pin connection at the firewall. The same unit sets in my '91 350SDL.

I'm trying to find a wiring pin out for these units.

That is the ABS/ASR controller, not the CIS controller.

If I recall the N3 is located behind the passenger rh kickpanel.

__________________
Paul

Then why do the units I have require a 35 pin cable?

The ABS/ASR controllers (N30) (located at the firewall) are 35-pin units.
The CIS-E controller (N3) (located in the RH kickpanel) is a 25-pin unit.

I will pull the kick panel tomorrow and see what I find. I had it off to change the O2 sensor but really did not check much more. Thanks for the info.