98 to 99 PCM swap.
Thread Starter
Teching In
Joined: Mar 2010
Posts: 14
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From: Needmore, Pa
98 to 99 PCM swap. Ive done some searching on here but cant seem to find any solid answers. I'm getting ready to swap my 98 PCM to a 99 PCM. I know i need to repin the harness and do a fuel segment swap to get the fuel gauge to work. Is there anything else that i need to do? Also any tips would be helpful.
I would upgrade to the 99+ PCM for sure with your setup. Preferrably, you should get an 01-02 PCM. The 98 PCM is fine for heads/cam cars, but the extended amount of tables in the 99+ helps out a lot.
It's not very hard to do. I've picked up several 98 harnesses for swap cars and repinned for the 99+ PCM. Just find a pinout list, label everything well, and start swapping!
It's not very hard to do. I've picked up several 98 harnesses for swap cars and repinned for the 99+ PCM. Just find a pinout list, label everything well, and start swapping!
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Thread Starter
Teching In
Joined: Mar 2010
Posts: 14
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From: Needmore, Pa
I would upgrade to the 99+ PCM for sure with your setup. Preferrably, you should get an 01-02 PCM. The 98 PCM is fine for heads/cam cars, but the extended amount of tables in the 99+ helps out a lot.
It's not very hard to do. I've picked up several 98 harnesses for swap cars and repinned for the 99+ PCM. Just find a pinout list, label everything well, and start swapping!
It's not very hard to do. I've picked up several 98 harnesses for swap cars and repinned for the 99+ PCM. Just find a pinout list, label everything well, and start swapping!
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Teching In
Joined: Mar 2010
Posts: 14
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From: Needmore, Pa
Car was originally a 6 speed. Plus the 4l80 is a manual valve body so thats not really the reason why im doing the swap. I want to be able to tune the engine better. im shooting for 20psi on 93+100% meth.
11 Second Club
Joined: May 2010
Posts: 42
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From: DFW
First hand experience doing the entire swap myself and working with tuners on this.
No issues with low oil light. Yes the stock fuel level gauge DOES work with a 0411 PCM, you just need the correct file from HP tuners.
No issues with low oil light. Yes the stock fuel level gauge DOES work with a 0411 PCM, you just need the correct file from HP tuners.
I feel your pain on the limitations of the 98 PCM, the major disadvantage is lack of a custom OS, at least for efi live. I just installed an ls7 maf and will be scaling the tune to not limit the maf Hz/max airflow limits as I max the airflow at 4000rpms currently. I don't want to deal with repinning the PCM not to mention efi live tunes 98 PCMs for free, so this is the best option in my opinion.
Staging Lane
Joined: Nov 2012
Posts: 77
Likes: 1
From: Stratford, Ct
I feel your pain on the limitations of the 98 PCM, the major disadvantage is lack of a custom OS, at least for efi live. I just installed an ls7 maf and will be scaling the tune to not limit the maf Hz/max airflow limits as I max the airflow at 4000rpms currently. I don't want to deal with repinning the PCM not to mention efi live tunes 98 PCMs for free, so this is the best option in my opinion.
Check my sig, both 98 cars and haven't used a license. 
Teching In
Joined: Mar 2024
Posts: 4
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99+ ecm on my 98 T/A I did the swap on my car from a 98 ecm to a 99 newer ecm now my service engine light is flashing and running rough ,, any ideas ? I left some wires out by mkr Motorsports instructions
many help will be appreciated.
thanks
Teching In
Joined: Mar 2024
Posts: 4
Likes: 0
99+ ecm on my 98 T/A I did the swap on my car from a 98 ecm to a 99 newer ecm now my service engine light is flashing and running rough ,, any ideas ? I left some wires out by mkr Motorsports instructions
many help will be appreciated.
thanks