98 ls1 harness pcm repin to work with a 99+ pcm
12-06-2011, 12:19 PM
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Car: 1989 pontiac firebird formula 350
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98 ls1 harness pcm repin to work with a 99+ pcm
Hey guys I'm doing an ls1 swap into my 89 firebird and I have a 98 camaro donor car. The thing is I don't want to use the 98 pcm and would rather use a 99 or newer pcm. I heard you can repin the 98 harness to work with the 99 pcm, is this true? And if so is there anything else that needs to be done to the harness or engine?
12-06-2011, 01:00 PM
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Re: 98 ls1 harness pcm repin to work with a 99+ pcm
there is a ton of wiring info over here:
http://lt1swap.com/wiringharness.htm
many 98 owners do this for better tuning help/resources
label everything you can on the 98 harness and double check your work. just unpin and follow the 99+ fbody schematics and you should be good
http://lt1swap.com/wiringharness.htm
many 98 owners do this for better tuning help/resources
label everything you can on the 98 harness and double check your work. just unpin and follow the 99+ fbody schematics and you should be good
12-06-2011, 09:23 PM
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Re: 98 ls1 harness pcm repin to work with a 99+ pcm
Yes the 98 harness can be used to build a 99+ swap. Anything else? Yes, Id suggest taking it apart and sorting through whats needed and whats not, then rebuild it to fit your engine bay the best
12-07-2011, 08:52 PM
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Re: 98 ls1 harness pcm repin to work with a 99+ pcm
Ive done this before and it works fine.
I have a pinout step by step in word if you want it.. just send me a PM it was from chipsbyal or something like that. he recommends making some wires longer
I have a pinout step by step in word if you want it.. just send me a PM it was from chipsbyal or something like that. he recommends making some wires longer
Last edited by 88 350 tpi formula; 12-07-2011 at 09:37 PM.
07-18-2012, 04:38 PM
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Transmission: 700r4
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Re: 98 ls1 harness pcm repin to work with a 99+ pcm
Thanks for the info guys. I will be labeling the harness and will be remove things I dont need and get ready to mock it up as soon as I get the short block back from lme.
07-18-2012, 10:54 PM
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Re: 98 ls1 harness pcm repin to work with a 99+ pcm
The link below has pinouts for engine PCM. This will help you figure out what wire to run to which location on '99 ECM.
http://www.ls1tech.com/forums/conver...swap-faqs.html
You'll have some wires that are not needed that were part of emissions system and such. Don't pull those wires out of the PCM connector or water will get in through the holes where the wires used to be. Just snip the wires about a foot from the PCM connector, tape, and bundle out of the way.
http://www.ls1tech.com/forums/conver...swap-faqs.html
You'll have some wires that are not needed that were part of emissions system and such. Don't pull those wires out of the PCM connector or water will get in through the holes where the wires used to be. Just snip the wires about a foot from the PCM connector, tape, and bundle out of the way.
03-18-2016, 09:51 AM
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Re: 98 ls1 harness pcm repin to work with a 99+ pcm
Can I get this info if you still have it ?
I have a buddy that I am trying to help .....
Thanks ,
Robbie Sheffield
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06-06-2022, 08:37 PM
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Re: 98 ls1 harness pcm repin to work with a 99+ pcm
I am in need of the repin step by step please.
My ecu is fried on my 98 5.7 ls1 and can only find the 99 5.7 ls1 ecu. I really need my car up and going. Thank you in advanced.
Michelle
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