First of all I hope this is in the right section but here goes...

Hey guys, I am in the process of installing a 6.0 (LQ4) dbw truck engine into an older car. I bought the engine off a yard that mostly deals with diesel trucks and the owner had (what seemed like) very limited knowledge on LS based engines. He told me he bought the truck at an auction (front end damage) because he needed the ECU and TAC module out of it. I bought the engine a few months later with a harness and gas pedal but missing the ECU/TAC. My problem is after researching, I don't really know what ECU I need to buy. To make matters worse, the owner doesn't remember what year the engine is but thinks its a 2004. It has 317 heads and the blue/green ECU connectors but that didn't narrow it down enough.

My question is: can any 03-07 ecu be used as long as it is flashed with the correct tune/OS (if that is the word for it)? I was given a gas pedal which seems to have the 03-05 harness stuck to it so I assume I can use the 12573058 TAC. A magazine (think it was GM High Tech) said that the 03-07 ECUs are interchangeable yet a poster on monodax.com said that the service codes need to be correct or the throttle control won't work.

If anyone has any insight, I would appreciate it - as I am about out of patience with the amount of research I've done on this and am about to turn this 6.0 into a boat anchor.

Also, before anyone sends the link to the lt1swap site, I've already read the How to ID your engine page many times. Seems like w/o an ECU or TAC it's almost impossible to know the year of the engine. I also saw possibly the last 6 of the VIN is etched on the rear of the block but my block is real rusty and flaky. Seems like so far my only options are to go carb, convert to DBC, or re-pin a 411 PCM...all of which seems like a PITA. on top of all this my buddy TrikeMike got a new lady named Nadine so he hasn't been able to help me much!

Thanks

 

All that **** is junk, just get a carb.

 

Did they let you out of jail already? Damn time has gone by fast! It almost seems like yesterday when I heard you were gonna be locked up for 12 years.

 

You told me running a carb was a sin...not a federal offense.

 

Hope you didn't drop the soap!

 

Come on man...you were the one trying to knock it on the floor....you're just mad you don't have a g body on jack stands.

 

I don't think the engine year matters. You need to find out what year harness you have. Do you have somewhere you can get wiring harness diagrams for 03-07 trucks, compare them, and make sure they are the same? If they are the same, then any 03-07 PCM should work.

As far as DBW controls go, in that 03-07 year range, you will be fine as long as your TAC, throttle body, and pedal all came out of the same year/make/model/engine vehicle. For instance, I am using an 05-06 truck harness and an 06 truck PCM, and a C5 Corvette TAC, throttle body and pedal.

 

Yeah, I meant year of the harness...I figured the blocks were pretty much all the same. After reading LT1swap.com (http://lt1swap.com/identify_vortec_engine.htm), it looks like the 03-07 truck harnesses are pretty much the same or similar enough to not matter once you modify it to be a stand alone.

At this point I am narrowing down the year based off my throttle pedal harness. It looks like the one he (LT1swap) shows as a 2005 harness...which falls under the 03-05 generation (says 06-07 have a different 10 pin connector). He also says that the TAC module #12573058 works for all 03-05...so I guess I could use that. To further narrow it down, the PCM generations are listed as 03, 04, and 05-07. Since I know my throttle pedal harness is not 06+, that would knock out the 05-07 generation of PCM service numbers, leaving me with either an 03, or an 04 engine/harness/throttle pedal/pedal harness.

So to sum it up (tell me if this sounds right!) Knowing that I probably have an 03-04 engine and that the TAC module #12573058 worked for the 03-05 trucks...I should be fine (since the TAC is the only part of my throttle control missing. I'm still a little torn on the PCM service code matching thing. Seems like it may not be a problem since there a lack of info on the subject. I'm sure if you HAD to have the exact PCM right down to the service numbers, it would be a well documented fact. I think you are right about any 03-07 (or in my case any 03-04) PCM should be ok to run. By the way, I appreciate the info.

Maybe tomorrow I can, like you said, look at some schematics and really lock in what year harness I have.

 

if your using blue/ green connectors, ecu 12586242 will work with tac and pedal. I used a vette pedal with a silverado sensor because the truck pedal assembly was huge. I bought mine off ebay (2004 silverado) and sent it to tunedbyfrost and he built the tune based on all of my mods.