Ls harness & computer question
- Thread starter Tomeal
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I finished my LS swap harness early in the spring for my 5.3LS swap. In all my research pretty much any LS harness should work, Red/Blue, Green/Blue. I've done 2 harnesses and in both cases I used the 99-02 Red/Blue 411 ECM because I wanted to go DBC and I'm pretty sure some of the DBW ECU's don't have the drivers for the IAC valve for DBC. If you use a Green/Blue harness the connectors won't plug into the Red/Blue ECM, you need the Red/Blue end connectors. In both cases I re-pinned my harness to a 2002 Camaro pinout, removed what I didn't need, EGR, downstream CATs etc. Then flashed the ECM to a 2002 Camaro OS (figured the tables etc. would work better than a truck config). Also did that because I put in a 4L80 and with the Camaro OS I was able to do the 4L80 segment swap. The Red/Blue harness & ECM should be plentiful in the yards (I scavenged 3-4 of them for stock). Look in most of the trucks for an ECM ending in 411, pop the connectors off (7mm socket) look for Red/Blue connector, that's your harness. IMO
Yes I do. Fired up instantly (pleasantly surprised), just had 2 alternator codes which I turned off in the tune (not applicable), and 1 transmission code, forgot 1 pin on the 4L80 swap. Just had to do a little idle tuning to get the idle the way I wanted it. The 5.3L has a Z06 cam and T76 turbo. Just got my driveshaft made so need to see how it drives.
One concern to think about if you are planning a new LS swap is that stock ECM tuning has been under heavy EPA scrutiny in the last few months.
Hptuners and stock ECM's used to be the cheapest way to go. The stock harness was essentially free with the engine and if you could spend some time rewiring it yourself to make it standalone it was a great option. If you owned HPtuners ($500) or had a friend that could tune it for you ($100) to turn off the VATS and make some small changes like fans or speedometer it was relatively cost effective considering the high price of a lot of other aftermarket EFI systems ($2k+). HPT also had good user support.
However the EPA really cracked down on that and the tube cabinet HPT hosted that you could reference is gone. You are basically HPT's poisoner and they can administratively pull your ability to tune new cars if the EPA says so. They hold the keys to you unlocking new ECM's (you have to buy the $100 unlock credits every new ECM you do) so the $500 investment is OK if you plan to tune multiple cars over the years but if you are going to do it once or want to get into it now, there is a chance the EPA could shut HPT down and you loose the $500 investment.
Holley TermX is $1000 which isn't cheap but the harness is already done, the user interface is 10X easier, and you aren't beholden to HPT allowing you to use the software you paid for.
If I was starting fresh, had to buy a harness and ECM separately and it wasn't fee on the engine, or I didn't own HPT or have a friend that would do it on the cheap I would seriously consider going to an aftermarket control system like TermX or other.
Hptuners and stock ECM's used to be the cheapest way to go. The stock harness was essentially free with the engine and if you could spend some time rewiring it yourself to make it standalone it was a great option. If you owned HPtuners ($500) or had a friend that could tune it for you ($100) to turn off the VATS and make some small changes like fans or speedometer it was relatively cost effective considering the high price of a lot of other aftermarket EFI systems ($2k+). HPT also had good user support.
However the EPA really cracked down on that and the tube cabinet HPT hosted that you could reference is gone. You are basically HPT's poisoner and they can administratively pull your ability to tune new cars if the EPA says so. They hold the keys to you unlocking new ECM's (you have to buy the $100 unlock credits every new ECM you do) so the $500 investment is OK if you plan to tune multiple cars over the years but if you are going to do it once or want to get into it now, there is a chance the EPA could shut HPT down and you loose the $500 investment.
Holley TermX is $1000 which isn't cheap but the harness is already done, the user interface is 10X easier, and you aren't beholden to HPT allowing you to use the software you paid for.
If I was starting fresh, had to buy a harness and ECM separately and it wasn't fee on the engine, or I didn't own HPT or have a friend that would do it on the cheap I would seriously consider going to an aftermarket control system like TermX or other.
Agree with the Holley TermX for an aftermarket engine management system. I got my harness with the engine and had HPT. One other thing to think about as well with a stock ECM is other functions it can do. I'm keeping my AC so I have it wired to control the compressor, fans, idle etc. Also any transmission tuning. Not sure what transmission you are using.
Maybe things are different in the midwest.....but I've engaged in 100's of CL and FB deals and haven't been screwed over yet.
I would say local salvage yard operators are more shady than the average FB or CL seller.
Don't forget that it comes with a new wideband O2 sensor as well.
They have gone up in price due to the Covid tax, but one to run the engine and transmission used to be $1150, but I believe they are $1250ish now if you're using DBC. DBW adds another $100 or $125.
Regarding outputs, the Term X can handle all the ones that Ostrich is referencing. There are 4 open outputs and 4 open inputs. Fan, idle kickup, a/c compressor and still have one extra left if you're only using one fuel pump and no boost control.
Holley gets you with the additional parts if you want to use them. Price out a setup with all Holley brand sensors, injectors, coils, TB, intake, etc. - yikes! But everything GM will work. And now most everything Ford Coyote or New Hemi works as well.
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