MSefi.com read only forum (Jan.15,2018)

I am finally starting installation of my MS. I plan on installing the ignition system first, testing it on carburation, and then adding the FI once I know the ignition system is functioning properly.

So, I am using a Saturn GM DIS ICM. I have been reading for days and just can't get it all straight. It would be great if someone could fill in the large holes in my own knowledge/research with real confused person proof answers.
Here is the way the ICM is set up and what I have figured out so far;

A-Yellow --- VR signal
B-Purple --- VR signal
C-no wire
D-Black/Red --- Ground
E-Black/White --- Ground

A-Pink Black --- 12 volts input
B-Yellow/Black ---
C-White ---
D-Purple/White ---
F-Tan/Black --- Bypass Relay

The assembly wiring diagram shows the VR sensor going into MS. Does it hook up to MS, the ICM (wires A and B), or both somehow My next question is how do you hook up the "bypass relay"

I found this nice diagram, but it is for the v2.2 board. How does it pertain to the v3.57

Let me know the year and model the Saturn DIS is off of and I will look up its wiring diagram.

I am kicking my self in the behind for not making a note of it, but I think it was either the 92 or 98 4 cylinder.

A '98 probably wouldn't have had this module. Here is what to do with the wires if it's a '92.

Pin B / 6X REF: Do not connect.
Pin C / EST: Pin 36.
Pin D / REF HI: Pin 24.
Pin F / Bypass: 5 volts through a relay so it only gets the signal in Run and not Start.

Could you give me more info on the bypass thing. I know how to set up a relay, but where are the relay signals and the 5 volts coming from?

The relay signal would come from the ignition switch - a terminal hot in Run but not Start. The 5 volts is from the MS VREF terminal (pin 26).

So the relay should be set up so that when the key is in the RUN position, the relay completes the connection between the tan/black and the MS VREF terminal (pin 26)...? After this clafification, I think I will be ready to go .
Thanks, Matt. As always, you are a life-saver.

Yes, that's how the relay works. Good luck with your project.

Oh crap, I forgot to ask what the E wire on the A-F socket of this DIS goes to. Damn! Matt....., Anyone...?

I am thinking that the A-F plug, pi n E goes to the tachometer...? Should I use this or the one out of the MS?

Also, unlike cars, most motorcycles (older ones at least) don't have a start position that only puts power to some things and not others. As an alternative, shat about using one of the relays that has the 87a output? I could set it up so that the 'run' power came from the 87a pin and the relay was triggered off of the starter power. That way when the starter received power and the bike was cranking, the relay would disconnect the power from 87a and put it to 87 (which wouldn't need to go anywhere).

cahillicus wrote:I am thinking that the A-F plug, pi n E goes to the tachometer...? Should I use this or the one out of the MS?

I'd use the GM DIS module output first and see if it works.

Also, unlike cars, most motorcycles (older ones at least) don't have a start position that only puts power to some things and not others. As an alternative, shat about using one of the relays that has the 87a output? I could set it up so that the 'run' power came from the 87a pin and the relay was triggered off of the starter power. That way when the starter received power and the bike was cranking, the relay would disconnect the power from 87a and put it to 87 (which wouldn't need to go anywhere).

That should work.

So in the MS wiring diagram it shows pin 26 (5Vref) going to the TPS. Is it cool to just split it with one going to the TPS and one going to the ICM?

Yes, you can use the VREF for more than one output in this particular case. The only real danger is when you hook the VREF to something that can pull it to ground, like an on/off TPS.