Upgrading a 98 to 03 PCM - wire conversion?
Thread Starter
Racer
Joined: Aug 2005
Posts: 350
Likes: 0
From: Boise ID
Upgrading a 98 to 03 PCM - wire conversion?
Anyone ever convert a 98 PCM to a later model 03?
GM changed the two 80 pin connectors wire locations to avoid crosstalk in the later version PCMs...
I would love to find a wire conversion harness that made this a simple plug and play.
Anyone ever come across this?
thanks,
Bob
GM changed the two 80 pin connectors wire locations to avoid crosstalk in the later version PCMs...
I would love to find a wire conversion harness that made this a simple plug and play.
Anyone ever come across this?
thanks,
Bob
Thread Starter
Racer
Joined: Aug 2005
Posts: 350
Likes: 0
From: Boise ID
1) my 98 PCM may be partially fried due to incorrectly installing my rear o2 sensors and melting the wires on my LT headers...after fixing this, my scan data now suggests that new 02's are still supplying bogus info.
2) if I am going to replace the PCM, why not upgrade to the new version with more internal memory and data aquisition capability? I can then use the later version MAF (with 5 to 3 wire convertor) and take advantage of the newer PCM tuning capacity for mass air flow (higher frequencies).
I have the 97-98 PCM vs. 01-03 connector differences layed out in an Excel file and virtually every wire has to be changed.
If someone were to offer a cable/connector harness than did the wire relocation, I would be happy....but the thought of manually pulling and relocating 160 pins does not sound fun.
I will most likely give this idea up and stick with a standard 98 PCM.
I just thought maybe someone else had come across this and had a solution.
Thanks,
Bob
Race Director
Joined: Dec 2004
Posts: 13,760
Likes: 75
From: Haymarket VA
I've looked into this. The later model PCM's have a faster processor and additional table room. You'r going to have to change harness, instruments, sensors and a lot more. It's not really worth it. Find a good tuner and you won't need it. My 500RWHP 402 drives like stock.
Burning Brakes
Joined: Jan 2013
Posts: 1,091
Likes: 1
From: Hercules CA
Don't mean to bring up ANCIENT threads, but I'm in the process of doing a h/c install on my 98 coupe. Goal is to get around 500rwhp or as close possible, but my question is; will my 98 PCM manage the tuning for such mods? All depends on the tuner correct? Or is my 98 PCM going to limit my gains?
Racer
Joined: Jul 2011
Posts: 455
Likes: 0
From: Dalton GA
No the 98' PCM will not limit your gains. From what I learned from my tuner is that the data logging and tuning process is a little bit slower on the 97-98 models. As far as performance I would say that as long as you have someone that knows what they're doing then he can still take full advantage of the mods you have. Hope this helps.
I'm in the process of putting a LS2 I'm my 98' and I ask him the same question if I should change my computer over and he said no that he could take care of it.
I'm in the process of putting a LS2 I'm my 98' and I ask him the same question if I should change my computer over and he said no that he could take care of it.
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Burning Brakes
Joined: Jan 2013
Posts: 1,091
Likes: 1
From: Hercules CA
No the 98' PCM will not limit your gains. From what I learned from my tuner is that the data logging and tuning process is a little bit slower on the 97-98 models. As far as performance I would say that as long as you have someone that knows what they're doing then he can still take full advantage of the mods you have. Hope this helps.
I'm in the process of putting a LS2 I'm my 98' and I ask him the same question if I should change my computer over and he said no that he could take care of it.
I'm in the process of putting a LS2 I'm my 98' and I ask him the same question if I should change my computer over and he said no that he could take care of it.
Thank you! This was the answer I was hoping to get! GL with ur ls2 swap!
Race Director
Joined: Dec 2004
Posts: 13,760
Likes: 75
From: Haymarket VA
FWIW: I ended up ungrading my PCM but my car is pretty well optimized. The stock PCM won't limit your peak power but in the hands of a good tuner, the later model PCM's can result in better drivability. They are faster and have more detailed tuning tables.
Le Mans Master
Joined: Mar 1999
Posts: 6,029
Likes: 85
From: Palm Coast, FL
no simple plug-n-play for changing it but I remember picking up almost 2 tenths when we changed the PCM - 4DRUSH told me the same thing ...
the 97-98 version is a little slower than the 99 and newer...
the 97-98 version is a little slower than the 99 and newer...