1227730 to 19196401 pinout

[Maverick H1L]

It took me a while to decode some of the pics and get these things somewhat organized, but I need someone to check me on this. This swap will be performed on my 87 Firebird that has the 3.1 in it, currently running on the factory 302 system. I have a harness from a 91 I will be using as a mock-up for this. I have already had the car running on the factory AUJW MEMCAL with the 7730 system, but there seems to be a fault in the harness, so I took it back out. The harness will be used for mocking up the system only to make sure I have continuity in all the right places and for locating new wires, etc. I plan on doing a 3100 small-port head and intake swap this spring, if I can get everything together.

Anyways, I figure it would be simpler to go from the 7730 harness (91 LH0) to the 6401 ECM from a 94-95 LQ1. Unless someone says otherwise. Right now, the current set up has a manual trans in it (but with the electronic speedometer), and I need to know what to do about the 4T60E wiring. If I leave it as is, will I end up with problems? Also, the same for the fan switches (only one fan here). What's the deal with the C3 and C4 terminals on the 6401? Is it possible to run a wire to my ALDL terminal B for trouble codes?

[Maverick H1L]

Also, anyone have any FACTORY wiring diagrams for a 98 Malibu? The one I got from AutoZone.com is way too generic and I need a little more data, especially on the top-end sensors. The FI and upper engine harness I am using, along with the 3100 top end, is from a 98 Malibu. I have the harness untaped and unloomed right now and am completely lost with anything other than the CTS and fuel injectors...

[robertisaar]

enjoy.

[Maverick H1L]

Thanks. I got most of it figured out with the 6401 wiring stuff you sent me, but there are a couple that don't match those diagrams. I'm assuming that the 5-wire near the TB IAC and TPS connectors is for the EGR valve (which I don't need as I have the older 4-wire one), and there are a couple others as well.

Have you looked at my text file to check me? Basically, IDK what to do about the trans range switch and the 4T60 stuff, as I have neither, and I don't want the ECM throwing any more fits than it's going to.

[robertisaar]

for the large part of matching the wires, you just need to match circuit numbers... as far as the 4t60-e related stuff: some of it isn't necessary. or at least it wasn't for me when i converted from the 94-95 3100 to the 91-93 3.4 PCM...

i'm looking through the file now.

[robertisaar]

ohhhh..... what a headache... i don't know how i pounded through this when i converted to OBD1...

[Maverick H1L]

So, basically, what you're saying is that I'm good just leaving those connections out? And what about the code flashing? For the 9396, the guide says to hook the ALDL B to terminal B3...

(I know I might sound like an idiot but this is kind of new to me... At least the 302 to 730 swap was made easier by the fact that they came from the same carline.)

[Maverick H1L]

Ugh. Just found out that I have to go a different route. (bangs head on wall) I finally figured out where the cam sensor is (didn't see it before) and realized "Duh! Can't do that with the 3100 setup, even if you DID have the hole (which I don't)!" Looks like I need to go back to the yard and grab that 49396... Unless I want to call around and see if I can't get that 3.4 that is supposedly not too far away from me... But then I need a truck. Ugh!

[Maverick H1L]

Plan is on track, but stalled out. I have the cam sensor I was looking for from an 87 Grand National (like a dizzy but not! ). I also have the 6401 sitting right here next to me (pats "new" ECM). Question: I've looked at a couple of sites to find info on the 6401 and found some broadcast codes, but none of them match what I have. Not only that, but the broadcast code on the ECM label doesn't match what's on the chip. The BCC on the box is BFJW, and the chip is BKXF. Anyone have any info on where these came from?

Also, I looked at another site. Am I supposed to expect this ECM to spit out OBDII trouble codes? If I am, well, I suppose I'm going to go with the backup 49396 plan, but I still need the cam sensor to go with the Buick quick-start DIS.

[robertisaar]

then that's not a 6401... both of those BCCs go to the 16177107 ECM... that's a 93 regal 3800 PCM...

[Maverick H1L]

I don't think GM made a misprint of the part number (possible, but unlikely?)... Left side, opposite of the BFJW, it says "SERV. NO. 16196401". But, you're the expert (not being an a.. here, that really is what it says). And yes, it was supposedly from a 93 3800 Regal, according to the white junkyard writing on it.

I thought that the 6401 wasn't used until 94? This is screwy...

[robertisaar]

I thought that the 6401 wasn't used until 94? This is screwy...

correct. it wasn't used until the 94-95 3.4DOHC cars.

[Maverick H1L]

Man, I must have a really weird thing here... I'll get a pic, because this is just, well, weird.

[robertisaar]

I'll get a pic, because this is just, well, weird.

good idea.

it is possible that the 6401 could have been used in place of the regal 3800 PCM, but i couldn't say for sure. some of the ECMs are capable of it, but this would be the first OBD1 ECM that i've heard of that crossed between the 60 and 90* V6....

[Maverick H1L]

The first pic is of the MEMCAL that came out of this weirdness, and the second one, well, as you can see, that's the weirdness itself. Looks like some of the white writing was rubbed off, but you can still barely see the "93" and "3800".