98 Model ECU question
Thread Starter
On The Tree
Joined: May 2004
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From: Rome,Ga
98 Model ECU question I have a 2000 LS1 engine i bought with a A4, i swapped the A4 harness and tranny for a T56 and the computer for it was a 98 model. The tab on the 98 computer has a peice broke off of it and i was thinking about replacing it, so im wondering if the 98 computer has different PIN locations or plugs that go into the computer from any other year.
I really want to replace it with a computer from the same year as the motor, because i dont know if any of the sensors have different values over the 98 computer specs. I remember from somewhere that the 98 model MAF tables in the computer wont read as high frequences as the MAF tables in a 99 up computer. Somebody please help me with this, im new to tuning EFI and this is my first LS1 build.
I really want to replace it with a computer from the same year as the motor, because i dont know if any of the sensors have different values over the 98 computer specs. I remember from somewhere that the 98 model MAF tables in the computer wont read as high frequences as the MAF tables in a 99 up computer. Somebody please help me with this, im new to tuning EFI and this is my first LS1 build.
On The Tree
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Originally Posted by LS1S10
I have a 2000 LS1 engine i bought with a A4, i swapped the A4 harness and tranny for a T56 and the computer for it was a 98 model. The tab on the 98 computer has a peice broke off of it and i was thinking about replacing it, so im wondering if the 98 computer has different PIN locations or plugs that go into the computer from any other year.
I really want to replace it with a computer from the same year as the motor, because i dont know if any of the sensors have different values over the 98 computer specs. I remember from somewhere that the 98 model MAF tables in the computer wont read as high frequences as the MAF tables in a 99 up computer. Somebody please help me with this, im new to tuning EFI and this is my first LS1 build.
I really want to replace it with a computer from the same year as the motor, because i dont know if any of the sensors have different values over the 98 computer specs. I remember from somewhere that the 98 model MAF tables in the computer wont read as high frequences as the MAF tables in a 99 up computer. Somebody please help me with this, im new to tuning EFI and this is my first LS1 build.
2000 PCM and 98 harness your in for some pin swapping. Also the 98 has a 3 pin coolant sensor, just ignore the green wire(depending on what your using for your dash gauge) for the 2000 pcm and you should be fine. Some other changes in the harness as well, I can't remember exactly but I think the alt wire goes to the PCM as well. Probably not worth the effort though.
Thread Starter
On The Tree
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From: Rome,Ga
So basically there isnt any performance differences or options with a newer PCM vs the 98 model ECU. If not then i guess it would be best to just stick with a 98 model and get a new one from the dealer. My harness is a custom made engine management harness from Current Performance made for a 2000 engine and 98 ECU, i was just wondering if they were interchangeable without any hacking. I dont want to go swapping wires around in $650 of fine workmanship.
So performance wise there isnt any edge or difference in having a newer model ECU over a 98 model?
So performance wise there isnt any edge or difference in having a newer model ECU over a 98 model?
TECH Senior Member
Joined: Nov 2001
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From: Lake Zurich, IL
from my understanding the processing power of the 98 PCMs is slower than that of the 99s.... however for our applications I don't know that it matters... there are plenty of fast 98s though so seems that PCM is just fine 
if your wiring harness is designed for a 98 PCM then you're locked to that... 99-02 used the same harness so you can swap the PCMs and flash for the year (or flash however you want... i'm an 00 car running an 02 PCM tune)
if your wiring harness is designed for a 98 PCM then you're locked to that... 99-02 used the same harness so you can swap the PCMs and flash for the year (or flash however you want... i'm an 00 car running an 02 PCM tune)
TECH Addict
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The 98 PCM is slower, and it does not support many features the newer PCMs have. And yes, it does not support the frequency range of the newer 85mm MAFs. It also does not have timing tables that extend as far as the later ones, along with a few other tables. The 98 PCM is the worst one...unfortunately for me...
Thread Starter
On The Tree
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From: Rome,Ga
So basically, are my options tuning wise with something like HP tuners limited? Eventually i might end up putting a turbo or nitrous on the motor, so would the 98 ECU support this fairly well or am i setting myself up for problems? And there isn't any clash between the sensors, MAF and such on a 2000 engine powered by a 98 ECU?
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Originally Posted by LS1S10
So basically, are my options tuning wise with something like HP tuners limited? Eventually i might end up putting a turbo or nitrous on the motor, so would the 98 ECU support this fairly well or am i setting myself up for problems? And there isn't any clash between the sensors, MAF and such on a 2000 engine powered by a 98 ECU?
You should be fine except for that turbo part. That could be where the ECU lets you down.
