05 Z71/ECM Question/ My dream will live again!

Disclaimer: Links on this page pointing to Amazon, eBay and other sites may include affiliate code. If you click them and make a purchase, we may earn a small commission.

Electrician

Full Access Member
Joined
Apr 20, 2022
Posts
139
Reaction score
308
I'm the new owner of a white '05 Z71 Tahoe! Sunroof, Bose premium sound system w/ oem screen for Navigation system, digital dual-zone climate controls, split captain style backseats, etc. I got it for $500 with a clean title! Great deal even tho... I bought it minus the motor/transmission, front clip, and ecm. They had already been parted out of it. But since what I need is a frame and body from my wrecked '02: viola! My motor and tranny into it and use my '02 front clip on it (it has Z71 lower valance on it already anyway) So it's more or less gonna be a Z71 turned RWD, I think. So '05 ecm is probly what needs to happen? Anyway, an awesome bonus from this: I also now have a '05 cluster to play with :)
Yeah. Get ready!
 
Last edited:

iamdub

Full Access Member
Joined
Apr 23, 2016
Posts
20,821
Reaction score
44,943
Location
Li'l Weezyana
I'm the new owner of a white '05 Z71 Tahoe! Sunroof, Bose premium sound system w/ oem screen for Navigation system, digital dual-zone climate controls, split captain style backseats, etc. I got it for $500! Great deal even tho... I bought it minus the motor/transmission, front clip, and pcm. They had already been parted out of it. But since all I need is a frame and body from my wrecked '02: viola! My motor and tranny into it. The hard part: non canbus to canbus. I may just have to attempt it. I wanna use the newer style steering wheel and digital climate control and seats. So maybe get a 05 pcm? Harness is still in it. I'm new to any kind of merger of canbus/pre-canbus electrical systems. I'm all ears if anyone knows. But a awesome bonus from this: I also now have a '05 cluster to play with :)
Yeah. Get ready!


Making sure I'm tracking here: The '05 is complete minus powertrain, front clip and ECM and you're gonna swap those items from your totaled '02- yes?

I'm thinking all you might need is an ECM cuz I don't think the generations are compatible. I'm pretty sure everything else is within the body and your engine and trans will be plug-and-play. Not sure about the transfer case and front diff electronics. Not the sharpest on 4WD.
 
OP
OP
Electrician

Electrician

Full Access Member
Joined
Apr 20, 2022
Posts
139
Reaction score
308
Yeah I believe so. I had to edit some of my first post. I'm gonna start looking for an 2005 Ecm, but can I just use any other one or will it have to be reprogrammed?
 

Mudsport96

Full Access Member
Joined
Jun 6, 2020
Posts
1,322
Reaction score
2,122
Location
40.923,-89.488. Illinois
Im about 80 percent sure the ecm split is 03-05 and then 06 (SUV) and 06-07 Classic trucks is how it goes. Because GM changed the way the TAC module works. But there may also be a BCM/ECM issue where the Fuel gauge reads backwards. Again I don't remember the year split.
But, seeing as it would probably need VATS removed, you could just have it reprogrammed for an 05 and get by fine.
If your 05 is electronic throttle then your 02 intake wont work because the throttle body bolt pattern is different than the mechanical setup. It isn't alot of work just a bit making sure you have everything.
 

iamdub

Full Access Member
Joined
Apr 23, 2016
Posts
20,821
Reaction score
44,943
Location
Li'l Weezyana
Yeah I believe so. I had to edit some of my first post. I'm gonna start looking for an 2005 Ecm, but can I just use any other one or will it have to be reprogrammed?

I can never remember, but I think it will need to be reprogrammed to your VIN. Or maybe it's like the radio where it's "blank" and will sync with and pull the VIN, etc. from the BCM at the first power-up with key on.

I really don't think it'll be all that big a deal. Get an appropriate ECM (PCM?) swap on all your body parts. As for the engine and trans, I forgot you don't have the '05 engine. I was thinking you'd just swap the intake manifold onto it so it'd be plug-and-play. So, you'll have to source an intake manifold and throttle body. If you're feelin froggy, you can get an IM and TB from an '07+ and have a "TBSS" manifold upgrade. As for the trans, transfer case, front axle, etc., I'd just compare the plugs on your '02 harness and trans with those on the '05.
 
OP
OP
Electrician

Electrician

Full Access Member
Joined
Apr 20, 2022
Posts
139
Reaction score
308
My thoughts exactly on comparing the connections on the engine/trans to the harness connectors in the '05. And yes, my '02 is cable TB (last year I think). Is there a way to program an '05 ECM to be cable and not drive-by-wire as to reuse my TB or no?
 

iamdub

Full Access Member
Joined
Apr 23, 2016
Posts
20,821
Reaction score
44,943
Location
Li'l Weezyana
My thoughts exactly on comparing the connections on the engine/trans to the harness connectors in the '05. And yes, my '02 is cable TB (last year I think). Is there a way to program an '05 ECM to be cable and not drive-by-wire as to reuse my TB or no?

Directly answering, I'd say it could be made to work. But, it's not worth it. You'd be jumping through so many hoops to devolve. For one, the cruise control goes through the BCM and it operates the TB using that electronic DBW stuff. There's no reason to downgrade. especially when it'll involve so much extra work.
 
OP
OP
Electrician

Electrician

Full Access Member
Joined
Apr 20, 2022
Posts
139
Reaction score
308
So I guess I'm looking at 2 options:
1) get the 2005 ecm, electronic tb assembly and associated parts
Or
2) keep using my 2002 ecm, cable tb, etc and rewire as much of the interior canbus components as possible to work with it (hint: the cluster :)

I'm on the fence...
 
OP
OP
Electrician

Electrician

Full Access Member
Joined
Apr 20, 2022
Posts
139
Reaction score
308
This is it btw. My brother also noticed it has the hydroboost brake system. I don't know if that's Z71 standard or not. Anyone?
 

Attachments

  • IMG_2446.jpeg
    IMG_2446.jpeg
    470.3 KB · Views: 6

Forum statistics

Threads
132,312
Posts
1,865,755
Members
96,903
Latest member
Joe Hale
Top