Jon, I've been going over the '8746 hack - did you ever do anything with displaying the spark advance through WinALDL, and creating a fan control..? I'm thinking of using the EGR wire (since I don't use EGR) to control my auxillary electric fan...

I'm using the AIR select solenoid wire for IAT already, since I don't use the select solenoid, but I do use the divert solenoid.

 

I haven't had the time to fiddle with it. I'm looking into making a patch to use the air solinoid, air diverter, can purge, and egr outputs as rpm and or speed activated switchs. Only trouble is finding room for the code. I'll talk to a friend to point me in the right direction.

 

Sorry to dig up an old thread, but did anyone ever figure this out? I am trying to do the exact same thing with the EGR solenoid as a fan control. I am also trying to integrate temperature values for fan on and off.

 

I ran something like this on the bench. The code for the smog pump in one of the loops can be deleted and reworked for use to turn a fan on. Got cold feet about using it in the car since I didnt know how all the code fit together but once I get through commenting my 8063 stuff Im going to add it in so I can have my fan come on when I want it to rather then just run all the time. Only drawback is that the code in question is out of your reach unless you convert the ecm over to be romless.

 

I have seen something to that effect, but I am thinking it is a bit over my head right now. I JUST got this ECM running in the Jeep and I really don't want to rock the boat until I at least have another one to experiment with.

 

RBob posted a while back about displaying SA.

 

I just realized why doing this might be a bad idea. If I rename the ECU items to Fan On/Off, it may look good, but I bet the ECM will still use this as a qualifier for more timing. Basically, I'd effectively be running my engine without EGR, but with EGR timing and fuel mixtures. I wonder if I could compensate for this elsewhere in the BIN.
Probably NOT a good idea.

 

Thats why you use the smog pump outputs. They can be turned on and off with a flip of a bit. Best part is there are two outputs used so you can run two things off of the computer instead of the air select and diverter valve. I think it would be worth it to go romless to do this rather then run the engine w/o the egr.

 

There's only one small problem with that...my engine (1979-model AMC 360) doesnt have a provision for an EGR. I do see what you are saying, though. Let's see if I can find the smog pump stuff in the $61 hac I have.
EDIT: Didn't find it. Could it be somewhere else under a different heading? How about using the AIR diverter or the AIR Select outputs? Is that the same thing and how would they be controlled by temperature?

 

I think the stuff that controls when the egr comes on is on the rom, anyhow so either way youd have to convert over to have access to it.

 

That sux. I really don't want to convert to ROMless just yet. I don't feel all that comfortable with it. What all is involved in that mod? Don't you have to clip a pin on the ROM and then wire it to something else?

 

Oh, I dont think rbob commented that part. They should be on the MCU2 I/O. Search for the label L0801. That should get you to them. I havnt reached that part of the code in my 8063 so Im not much help yet.

 

There is a board available that you can solder in in place of the smaller daughter board in the ecm. You then only need to run one jumper wire. I have one but have yet to solder it in. The other ecm I have I did the hard way by doing lots of soldering. Do a search over on the dfi/ecm board. I started a thread over there and rbob gave good instructions on how to do it.

 

Well, that puts it on the outs for right now. We (my friend and I) have done soldering lately that didn't turn out so great.

 

Im not an expert but I did sleep at a Holiday Inn last night. Lol, J/K. I have done alot of soldering so here are some tips. One thing that you want to do is make sure you have the right equipment. Thie basics should include a low wattage (~15 watts) soldering pen with a fine tip, a desoldering iron (in case you make a mistake), and a damp sponge to periodicly clean the tip of the iron. One thing to make sure is that the tip is realativly new. Solder tends to errode the tip and having a fagged out tip doesnt help any. The tip should also be clean and tinned. Some other tips are not to blob the solder on, but only add enough to fully bond the components your working on. Also make sure to heat the joint that your soldering so the heat of the joint melts the solder and not the iron. That will give much better results. Lastly, dont use electrical tape on anything, always use shrink wrap to insulate all connections. If you follow those basic tips, youll get good results.

Heres pretty much what would be involved. The first panel shows the little board that has teh prom and the netres thingy on it. Thats the board you want to replace. The ribbon cable circled there is the part that has to be desoldered. It looks like the easiest way would be to use the method suggested, which is to use a small torch and uniformly heat the underside of the board to melt the solder to get the ribbon cable off. I suppose you could use the desoldering iron as well. I did get the large connector of of my test bench ecm using a desoldering iron w/o damaging either component (want the connector for something else).

The second panel shows the jumper that needs to be soldered in. In the ecm for the car youd want to make this a bit neater. This is the only wire that needs to be soldered in.

The last panel shows the board that replaces the other one. Neatly solders in and allows the use of a larger 256k eeprom.

I havnt done this yet. Maybe one of these days if I feel motivated ill finally convert my cars ecm over. Hopefully I wont mess anything up...

 

Famous last words...LOL. I said the same thing and nearly smoked a brand new ECM.
Once I get another ECM to play with, I may just try this to see if I can do it. For now, though, this thread is getting saved in my TO DO folder. It actually looks simple enough, but my soldering skills aren't quite up to speed for something as delicate as this.

 

hahaha! yeah, theres always the possibility of messing up. Luckily, these ecms are still available for not too much money.

 

If you have a trade-in, they're not prohibitively expen$ive. I only have a 7747 for a trade-in right now. I guess I could scrape the sticker off of it. Externally, the two (7747 and 8746) are identical. You'd have to plug in a chip and hook it up to be able to tell the difference. Hmmm....maybe a project for the first of April's paycheck...

 

The 7747 will work fine. Just load the $61 code on in its entirety and your off and running. I think I posted the $61 rom image on craigs ftp. Just grab the $61 rom image and add your bin on with 32k of empty space at the beginning of the chip and you should be good to go.

 

A ROMless 7747 on $61 code. I guess I didn't think about that one. Cool!!!
EDIT: Am I blind? I don't see it up there. I looked at all the folders, but no $61 ROM image.

 

As I was told (and found out), the hardware is the same for all the c3's. And any C3 code will work on them.

 

I knew the hardware was the same, but the code was different.

 

Ah, here it is. 8746 rom

 

Just as long as it has the WHOLE code on it, the 7747 will run just like an 8746 or whatever you make it to be.

 

Thanks!!! I may be using it in a few days just to try my habd at this. :yourock:

 

I dropped you a PM.

 

Got it...thanx!

 

Now if only lockers AND romless....
Trust me, lockers is worth it's weight in gold.
Here's another wish. A p4 with the same firing strategy as the c3 tbi. I guess a 7749 will have to do.
Dim, you've got mail.

 

Noob question here...what is lockers? Are you talking about a locker for a differential?

 

Lockers is a DIY kit that captures ALL of the computers ram and 6 extra 10-bit analog inputs 17 times a second. It's bar none the best data-aq system for a c3 ecm. I haven't used winaldl since I got lockers.

 

Where can one aquire this kit?

 

Sorry to drege up an old thread, but its a new topic for me many threads i read are dated back a year or so and I always wonder where stuff has been left off...

It says in the thread that esentially any C3 hardware (7747,8746) is all the same, (for the most part)

With the only differences being CODE/bin. So any complete code will run on any ECM, assuming the wireing/outputs have been modified, altered, reprogramed etc, for any differnece the code has...

My question is, why does it appear from my newbie viewpoint alot of attention is spent on specifc BINs, masks ??

Is this simply to minimize tuning ? or simply to avoid tuning ?

wouldn't it be simpler to run a common code base and simply repin the ECM harness to take advantage of a particualr code base or another ? Is this the appeal of the new super codes ?

Maybe this is common knowledge but i feel like some sort of light bulb just went off...

also to revalidate whats been posted. I can run code X on my 8746 and then use my 7747 as a spare ECM.