HELP!!! ECM connecter problem

As I'm getting closer to finishing the 5.3 LS Swap in my 06 H3, I'm finding all kinds of little electrical connector issues. Some connectors from the the donor motor don't match some just aren't even there compared to the wiring harness. I bought an OEM wiring harness for an 08 ALPHA and a 5.3 out of a Tahoe. As far as the some of the connectors not matching I can deal with either replacing the sensor or changing the connectors to work. The big one is the blue connector on the ECM. The 06 L5 computer had a slightly smaller connector and had the lockdown posts in a different position. Has anyone dealt with this problem and if so how did you fix it. The computer I bought for an 08 ALPHA works with the new wiring harness but will not connect to the blue connector on the truck that I believe runs power to the body control module ( not 100% about this). The company I bought the computer from said its not possible to do this swap.

2008 is substantially different than 2007 or prior. There are shops that can do the mod.

Waiting for Squeaky to chime in . . .

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I don't know of any other solution than getting that e67 controller connector and pigtail wiring from the junkyard and then splicing into your h3 harness. Many vehicles use the e67 controller so it doesn't have to be from a h3. I might have a spare colorado e67 harness pigtail and connector if you do not have a local u pick type junkyard nearby

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Current performance makes a jumper harnesses but only sells it as part of their full harness kit.

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I assume it would have to be 2008 or newer vehicle to get that pig tail from? Do you of a couple different vehicles off the top of your head that have it. I'm in Montana and we occasionally see a Chevy Colorado come through the yards here but I'm not sure about anything that new.

I saw their jumper, and got really excited but like you said I couldn't find it out side of buying the $1000 dollar harness kit. I was hoping some else made such a jumper or was hoping it was possible to have someone pull the two computers apart de-pin and swap the physical connectors.

Here is the full list of e67 controller vehicles. Pretty common in the junkyards.

https://gmflash.com/e67-pcm



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I wasnt able to find the appropriate plugs to make it plug and play, not sure where current performance is sourcing them from. They can likely buy in bulk where i just needed one.. Splicing isn't too bad, just get some shrink wrap, solder and a solder gun and spend an hour cutting and splicing.


I cut open a spare ecm to see if I could pull the plug out to make a jumper but it doesn't seem possible to do that or swap the plug inside the controllers. Maybe someone with some circuit board experience could do it, but not me.



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Awesome! This is all helping a lot. I've got the harness laid out and I've got some substantial wires that have no connecters that correspond on the truck or the motor.

One of which has an almost identical connection on the drivers side next to the battery but nothing to plug it into on the passenger side. Anyone have an idea where these go to?

I don't see how you can do this without getting 3 wiring diagrams and cross referencing where everything goes. You need your 06 h3, the 09 h3 alpha if that is the harness you are using and whatever year and model 5.3 you are using.

I can try to help but you will have the best success if you study the diagrams yourself.

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I've been cross referencing the 06 H3 and the 08 Alpha, the problem I'm running into even with the wiring diagrams is they don't seem to show the connections in between the wires starting and ending point. Plus the wire connections in question right now don't have a direct start or end. All four either cross through just the wiring harness or disappear into a large wire cluster that dives into the cab as well as splits and runs under the truck all the way to the rear of it. The 08 alpha wiring harness seems to have more connections then the 06 body has to connect to and some of the ones I've found that physically connect don't have wires that line up. If I could figure out where these leads ran to or ended at or even what they were supposed to control I believe I could get the wiring diagram and make the proper connections. I really apricate the help so far, I'm getting to a point where the length of this project, and want to drive my H3 again is wearing on me.

What wiring diagrams are you using? Also I think you were the guy that bought my 09 alpha engine harness right? The 08 and 09 have different wiring outputs to the body so that might be part of the problem.

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I think I am the one that bought your wiring harness, I thought it was an 08. I've been using schwarttzy diagrams, but I have been looking at the 08 not the 09.

I'm not sure why or how I got it in my head that it was an 08 harness. Do you have any good references for an 09 diagram?

I haven't used this myself but it might be worth a shot for the h3 diagrams. Ebay link below:


You never mentioned what year tahoe your 5.3 came from?

https://www.ebay.com/itm/Hummer-H3-...2349624.m46890.l49286&mkrid=711-127632-2357-0

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