PCM compatibility question for '07 4.3L V6 Silverado Classic (LS1 Gen III)

[dgiller]

Hi folks,

Can someone answer a LS1 PCM hardware/os compatibility question for me?

Can I do a full reflash and put a 2007 OS and tune on a 2003 1Mb PCM?

Does anyone know if all of the 1mb PCMs are electrically identical?

They're both Gen III 1Mb PCMs, but I don't know what else may have changed internally from year to year.

If I have a 2007 Silverado V6 that needs a new PCM, and I have a 2003 1Mb PCM on the shelf, can I reflash the 2003 PCM with the later 2007 operating system and tune, and will it work?

My application is actually a conversion: I have the engine and engine harness out of the 2007 that's going into a project vehicle. The wrecker provided a 2003 PCM as a 'compatible' part, but I'm not entirely convinced and don't really want to waste a VIN license if they're wrong. I thought they provided the PCM from the donor car, but they didn't, and I didn't notice that till it was far too late to take it back and swap for a later PCM. I can go buy another PCM but I'd rather save the time and money of getting yet another PCM and use one of the two 2003 1Mb PCMs I have on hand.

Also, I have a stock tune from a 2006 V6 Sierra pickup. If someone had a stock tune for a 2007 Classic Silverado V6, ideally a manual, that would be very helpful too. I suspect the 2006 and 2007 are identical, or at least that either will run my 2007 engine, but don't know that for sure.

Thanks in advance,
Dave

[GAMEOVER]

Is the V6 engine Drive-by-wire?

[dgiller]

No, it's not drive by wire. Standard cable-driven throttle body. I've wondered if any of the V6'es got DBW, but this one for sure isn't.

[ScarabEpic22]

Ohhh, good call GAMEOVER. I think the 07+ V6s that use the E37 are indeed DBW. Although can someone check the 06 V6 tune file dgiller has for any ETC tables? (at work without remote desktop right now) Would be easy to tell if its an ETC one or not (guessing not).

Shouldnt matter if a full flash is done on the LS1 PCM, the ETC stuff is probably populated with ignored values for V6s.

[dgiller]

Hi Erik, GAMEOVER,

I keep neglecting to say clearly that this is definitely a Silverado Classic... that is, LS1 not E37, and I suspect it's identical to the 2006. I just don't know for sure that the 2006 and 2007 OS for the LS1 V6 are the same, or whether I can load that OS onto the 2003 hardware.

It has tripped me up a few times that there are two totally different '07 Silverados, the Classic (old body style, LS1) and the regular (new body style, E37). I definitely have the Classic with LS1 and cable throttle.

Thanks,
Dave

edit: Erik, just re-read your post... I checked the 2006 tune and it didn't have the ETC option. G1207 Vehicle Platform Options has only "Alternator F Terminal" and "Low Resolution Crank" selected. The stock tunes from both of the 2003 PCMs I have also had "Low Resolution Crank" selected.

[ScarabEpic22]

Good to hear about the ETC not being available for that tune. The Platform options are easy to change and vary by model and sometimes year I believe, not a big deal there.

Know its an LS1 PCM, Ive thought about it and Im 99% sure ALL 1MB LS1 PCMs can accept any LS1 1MB tune. Its to the point now that Id give it a shot, worse case you use a license and then retune it to something else and sell it online or to a buddy.

[Taz]

Hello dgiller,

Sounds like you have an interesting project on the go. The 2003 to 2007 PCMs are NOT "electrically identical" - other than having blue & green connectors and 1Mb memory. DBC (Drive by Cable) application PCMs have an additional chip - to control the IAC. DBW (Drive by Wire) application PCMs don't use an IAC - and are missing this component.

2003 - 2007 PCMs from 4.3L trucks (S10 / Blazer / Sierra / Savana) are DBC. The only V8 PCMs I can think of in these years that were DBC were the 2004 GTO, and many (but not all) Savana / Express vans.

Your 2003 PCM may be DBC compatible - pending on the Service # and Hardware #. Your 2003 PCM may be compatible with the 2006 tune you have, but to confirm this you will need to use the "Test" function of the PCM Flash utility - which I believe requires licencing the PCM. This is a $100 gamble.

The 2006 tune that you have is compatible with 2005 to 2007 4.3L applications, and corresponding PCMs. Used PCMs from auto recyclers in my area can be purchased for around $50. That's the route I would go. The following PCMs support DBC and are compatible with your tune.

2005 & 2006: Serv #12589462 Hdw #12589161
2006 & 2007: Serv #12602801 Hdw #12589161

There are probably several more, but the above I know to be compatible.

Hope this helped .........

[joecar]

Hi Taz, good info, welcome to the forum :cheers:

[dgiller]

Great info Taz, thank you! I'll follow up also to your message on my question in the Conversions forum.

That's two parts of the info I really needed:

1. There are different 1Mb PCMs within the same year, with at least one difference being the ability to electrically drive an IAC.

2. A PCM from a 2005-2007 4.3L vehicle can probably operate any other 2005-2007 4.3L engine, as they were all DBC and used the same sets of sensors.

A brief comment that I'll pick up on in the other thread: the risk involved with wasting $100 on the VIN license is not the only risk. The hours and hours that could be lost by flashing an OS onto a PCM that can accept the firmware, but not operate properly afterwards (and potentially not give any outward indications as to why) is a much greater risk.

I guess I'll be buying another PCM (seeing them more around $85USD around here, but that is, as a friend says, "mouse nuts" in the long run).

Thanks!
-Dave