Hello all, first post here. Spent a long time lurking and it led to an LS swap into my 72 Chevelle (yeah, another one )

Background: Extreme minimum budget build. '04 LM4 purchased online from a junkyard arrived with a DBW throttle body and bits and pieces of a harness. No TAC, no pedal, no PCM. Most of the connectors are there with wire tails and I have a bitchin soldering iron, so I should be good to make my own harness.

I have a PCM from an 04 Silverado 1500 12586242 (no IAC control hardware) and one I picked up today since it was laying there and is a 12200411. The 0411 is from a V6 truck of some sort, I can't remember which one since I spent so long looking at so many different things. It shouldn't matter since, as I understand it, I'll have to have the entire thing rewritten to even get started with that. That would only be if I can't get the DBW thing figured out anyways. That's a separate question for another day.

I'd like to have the DBW instead of the cable, so I know I'll need the TAC, pedal and the harness that goes between them. The question is, will any of the 03-06 TAC and pedal combination work with the 04 PCM? Obviously the best situation would be to get an 04 Silverado TAC and pedal, but failing that, could I use the TAC and pedal from say, the 04 Rainier that the engine came from?

Searching shows a different TAC part number for the 04 Silv and the Rainier, and there are several other part numbers for 04 TAC modules that I have found. I'm wondering what the difference may be, and what the effects of connecting the wrong things together may be (besides nonfunctional throttles and wasting money).

I guess another way to ask would be, "Will any TAC and pedal combination that came in a vehicle with the 242 PCM work to drive my 04 throttle body, and does it matter which PCM?"

I don't want to punt and get a DBC throttle body, that would feel like cheating

Thanks.

 

From my experience, you should use the 04 truck pedal and TAC. Did a swap with an 05 truck 6.0 and they sent what turned out to be an 04 TAC module, which turned out to be incompatible with the 05 pedal. It was fine until you tried to go above something like 75% throttle, then it would code the tps and go into limp mode.

 

If you already have the 04 PCM, then use that. The 411 won't work, I tried it and you can't put an 03 or newer OS in it and make it work. Get a TAC and pedal, the metal one,from an 03 or 04 and you'll be good to go

 

Are you saying that the 0411 PCM won't work with a cable throttle body, or won't work on an LM4, or that the V6ness of it can't be wiped clean? Because that will definitely push me harder to get the DBW working.

 

The 411 will work for a DBC application just fine, it will also work with the 2002 annd older DBW, but the throttle body and TAC are different. The fact it came from a V6 doesn't matter. It just won't work with a 2003-up DBW set up. The 2003-4 TAC and pedal should be easy to find.

 

Gotcha. That agrees with the info I already have. Thanks for clarifying. The cable setup is still a backup plan anyways. I just want to make sure that the fallback plan is actually there.

 

Alright, I ordered up the TAC and pedal both from an 04 Silverado since that is the computer I have. I'll let you guys know how it works out. Should be starting assembly in a couple of weeks.

Thanks for the pointers.

 

I know the Tac module goes to the pedal, where does it get its signal from? I'm being told 2 different things. 1 is I can use a harness from the engine harness to the module and the other said it goes to a dash harness. I have a Mustang so no dash harness for me. Not sure what to get.

 

The TAC module plugs into the LS engine harness, and has a jumper harness from TAC to pedal. Doesn't tie into the dash harness, but on pre '03's, the jumper harness is integrated in a body harness. If you have that style, just get the jumper harness from an '03 to '07 and you'll be good to go, or you can cut both ends off and splice the wires back together.

 

ok so now i have a better understanding. I dont have any parts yet. So I need to buy a harness first. man it was a lot easier with my LS1 car then this LS3 motor 58x thingmajig.
any combo better then the other to use. corvette, truck suv? I want to try to buy it all together. thank you

 

You didn't say you had an LS3.... I don't think they have a TAC module, the throttle is straight out of the engine harness on them.

 

I have a L76 6.0 alum shortblock, 58x wheel, LS3 intake, and CNC LS3 heads. I didnt realize its only DBW and I'm not swapping to a 24 due to the motor is all together. so no harness or pedal till I'm sure what to buy. Tac module is something I just read last night so I'm totally lost on DBW. My old LS1 was so much easier

 

You can buy a 92mm drive by cable throttle body to work on the LS3 intake. To run the 411 style (red / blue connector P01 controller) which are all 24x you will need a conversion box from Lingenfelter.

A P59 (blue / Green connector) controller looks similar to the 411 style but started in 2003/4 and were typically drive by wire. The problem is the later Gen III controllers require the proper TAC, throttle body and pedal to match the OS in the controller. None of those that I'm aware of will drive the Gen IV / LS3 style throttle bodies.

 

I saw the lingenfelter box, but my injectors I think are a different connection on the LS3 intake I have if I use a LS1 harness.

 

ahhh looks like I can buy new adapters for the injectors

 

I'm a junkyard bandit on a budget. I took injector plugs from a car in the wreckers yard. Why buy what I can recycle?