Beginner question re: 2003 LM7 5.3 Vortec

[Jon95YJ]

When I say beginner, I mean I'm REALLY new here! Anyhow, I'm putting a 5.3 Liter Vortec LM7 engine from a 2003 Avalanche along w/ a 4L60E auto tranny from a 2003 Suburban into my 95 Jeep Wrangler. The stock engine in the Jeep was a 2.5 Liter engine w/ AX5 manual 5-speed tranny. I don't know squat about electrical or tuning and just happened upon this forum, so I'm hoping I've stumbled into the right place. The smart guy would probably pay a pro to flash the computer that came w/ the 5.3 Vortec to make it work in my Wrangler (the guy I talked to said something about making the LM7 engine and 4L60E tranny work as a standalone engine?), but unfortunately, I'm not that guy. I was thinking that instead of paying someone $500 to reprogram my ECM (?) and do some wire harness work, why don't I look into this tuner thing and try it myself and hopefully learn something in the process w/out blowing my engine/tranny up. Is this wishful thinking or is this a task worth pursuing? Thanks. -Jon

[nevinsb]

I am hoping you have the complete powertrain/body wiring from the Avalanche.

The PCM from the jeep will NOT work if that's what you are asking.

[Jon95YJ]

I am hoping you have the complete powertrain/body wiring from the Avalanche.

The PCM from the jeep will NOT work if that's what you are asking.

Yes, I have the COMPLETE wiring harness, computer, accessory package, etc. from the Avalanche 5.3 Liter LM7. I also have the complete harness, computer (?), etc. from the Jeep, but I figured that it would be worthless, but since I'm not sure, I want to hold onto EVERYTHING! I guess what I'm asking is if there is a snowballs chance in hell that I can do this myself. I like learning new things and get satisfaction from doing stuff, even if it is more of a pain in the ass than paying someone else to do it. I mean, even if it's a little more expensive for me to do it myself, I like having the know-how and tools to do it again in the future if I ever want/need to. -Jon

[nevinsb]

I thought the Avalanche and Suburban used the same PCM, so you should just be able to copy the transmission segment from the Suburban and flash it to the Avalanche PCM. This part of it will be easy, and one of the people on the forum should be able to help you with, but you will probably be on your own for the wiring. The GM Service manual for the Avalanche has a lot of wiring diagrams. it will probably be well worth your while to find one (Should run about 125 for the 3 volume set used).

$500 to have the wiring harness altered and the PCM flashed is actually cheap.

[joecar]

Jon, welcome to the forum...

It's doable...

but there are various learning curves... (fabrication, electrical, diagnosing, scan/edit/flashing...)...
you're transplanting a totally different powertrain into your Wrangler...
you will have to take care of anything that arises during the transplant.

What are your objectives:
- do you want to learn to get it all going by yourself (you will invest ALL your time, it will take a longer time), or
- do you just want to get it going in the shortest time (you won't learn very much, but it will get done);

If you DIY it will be your hobby and will use up all of your time...

You can download/install the actual V7.5 software from here and play with it:
http://www.efilive.com/index.php?opt...=48&Itemid=124

Without the cable/hardware you won't be able to log or flash...
but you can open/edit the sample log/tune files and play with them.

Cheers
Joe

[ChipsByAl]

You would also need the complete engine/transmission schematics for the Jeep. That will show you where to tie in one harness to the other.
Al

[Jon95YJ]

Ok... So if I do this, I'll need the FlashScan V2, right? I'm looking under the supported vehicles, and it seems to list mine (Donor engine is 5.3 L Vortec from 2003 Avalanche & donor tranny is 4L60E from 2003 Suburban), but my engine code is LM7, NOT LS1. So is this a problem or am I reading the chart of supported vehicles wrong? What else do I need (other than a boat load of knowledge...)? I already have the shop manual for the 95 Jeep Wrangler, and I can get the shop manuals for the Suburban and Avalanche. Anything else needed? Thanks. -Jon

[nevinsb]

It should have a LS1 style PCM.

[Jon95YJ]

On closer inspection, I don't see my tranny listed under the supported vehicles for the V2 scan and tune. Does that mean it doesn't have a separate computer and it's all controlled by the PCM for the engine?

[nevinsb]

The LS1 style PCM does not use a separate transmission controller.