School me.

I have done quite a few GM EFI powertrain swaps including LS family DBC and DBW. I usually completely rework factory harnesses but have built a couple NEW ones as well.

However I am still a little unclear about the differences btwn the red/ blue and green/blue Gen 3 PCMs. I have noticed differences in HO2S wiring and I think alt wiring.

What, if any other differences are there. Can either be used with DBC or DBW assuming proper cal application?

What are the different options for alternator wiring? Can the brown wire go straight to a charge indicator lamp provided that gen f terminal dtc is set to not reported? Does the gray wire always need to be ran to the PCM?

Thanks guys...

Yes, this site has a write on how to do it. It's as simple as pinning the PCM providing the PCM can control the IAC, not all can. My 03 PCM I tried using wouldn't so I picked up a 02 PCM...harness I used is a 05 6.0/80e harness. A few pins needed to be swapped or added but it was pretty easy. So 05 harness with 02 PCM and it's dbc

I think I should simplify my questions.

What are all the differences btwn the red blue and green blue pcms.

Can either be used with a cable or tac?

What are the options for alt wiring?

The blue and red connector harnesses are 99-02 and you should use that year pcm.
The green and blue connector harnesses are 03+.
You shouldn't try to swap between the two with pcm's.

Thanks, can the green blue pcms operate an IAC? Can the red blue pcms communicate with a TAC module via serial data? I do have a tuning software suite and can load the proper os and cal.

What exactly are the differences btwn the two pcms? Is one exclusively 512k?

For example, if I wanted to convert a blue green DBW harness/ pcm to DBC, can I keep the pcm and just rework the harness or would I have to use a 99-02 pcm?

Vise versa, could I use a red blue pcm in a DBW application?

What about alt wiring? How many different schemes are there?

Some of the '03 and I think '04 express vans used the mechanical throttle body, that is one vehicle that is an exception to what I stated above, but I'm not sure what pcm service number they use.

For the general rule, no, don't flash an '05 calibration into a 2002 pcm, weird things happen. They have different hardware internally.
You can convert the dbw harness to a cable operated one, but use a 2002 pcm.

Cool, so red blue pcm = DBC. Green blue pcm = DBW.

I will keep this advise, thanks!

Now can you or someone school me on HO2S variances. Is it just case grounded or not case grounded and wire them accordingly? Are they specific to early( not case grounded) and late( case grounded)? Anything else?

Alt variances?

Thanks a million for your time, I know you are a VERY busy man!

You'll have to look up each harness by vin to know exactly how it's pinned out, just to be sure, but 99% of the time when we do a cable operated throttle body 99-02, they are case/chassis grounded.
The newer trucks/cars 05+ seem to be pcm grounded.
Just a general observation, it's not the rule.
Almost all the 2002 and earlier use the one wire , flat connector.

A lot of your questions can be answered in the link I posted

Sorry, I don't see the link.

Forgot to mention I am in the middle of a 5.3 swap at home. Its a 72 k10 on 35s owned by a 17year old. Starting his senior year in two weeks. Fired it up late tonight. Should have it ready for his first day back. Cool stuff.

you must post pics or you are a proud member of the sadistic society !!!!! ;)

Will do. Does photo bucket work here? Ill start different thread will my conversions to date.

yes, Photobucket works perfect...is what I use !

I have an alt not charging after a swap. Its an 04 truck alt with a 99-02 red blue pcm. I have the brn wire from alt pinned to 15 red. Have the gray wire pinned to 52 red. Also this is in a 72 c10. I want the charge indicator to work. Any tips?

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Originally Posted by 2boosted

you must post pics or you are a proud member of the sadistic society !!!!! ;)

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Did I post enough pics? Lol

Quote:

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Originally Posted by vortecyota

I have an alt not charging after a swap. Its an 04 truck alt with a 99-02 red blue pcm. I have the brn wire from alt pinned to 15 red. Have the gray wire pinned to 52 red. Also this is in a 72 c10. I want the charge indicator to work. Any tips?

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the alternator won't charge correctly. you need an alternator with the long flat connector. old style is on and off, the new style which you have is pulse width.
you can make it stay on and charge, but it won't ever function correctly.

Oh, so basically the 04 pwm alt is not compatible with the 99-02 pcms? The connector is a flat 4 pin. Is that the connector you speak of?