ECM interchange
Thread Starter
Drifting
Joined: May 2020
Posts: 1,663
Likes: 702
From: Baton Rouge, Louisiana, metro area
ECM interchange
Is an ECM with its own PROM from one 1991 base L98 (say ECM/PROM “a”) directly interchangeable with another ECM with its PROM from a 1991 base L98 (say ECM/PROM “b”) with the same GM part number?
On my 82, the ECM change is just unplug, plug, start engine as long as the GM part numbers match. Is this process the same for 91’s as long as the ECM’s are the same?
On my 82, the ECM change is just unplug, plug, start engine as long as the GM part numbers match. Is this process the same for 91’s as long as the ECM’s are the same?
Oil Producer
Joined: Apr 2014
Posts: 9,371
Likes: 2,736
The ecu is 100% interchangeable.
the prom, may contain custom programming if the car is not stock. or, for example, the "memcal" chip may have had the 1-4 "skip shift" programmed out, or, the VATS programmed out. Or, a multitude of different other more complicated things like the fuel enrichment tables altered. Personally, I would not try to use another cars memcal ship on my 1991 unless i knew it was an unaltered factory chip.
the memcal chips can be swapped out though so if you are suspecting your ecu is fubar, then take the chip out of your car and put it into the new ecu and see if it works.
what are you trying to solve?
the prom, may contain custom programming if the car is not stock. or, for example, the "memcal" chip may have had the 1-4 "skip shift" programmed out, or, the VATS programmed out. Or, a multitude of different other more complicated things like the fuel enrichment tables altered. Personally, I would not try to use another cars memcal ship on my 1991 unless i knew it was an unaltered factory chip.
the memcal chips can be swapped out though so if you are suspecting your ecu is fubar, then take the chip out of your car and put it into the new ecu and see if it works.
what are you trying to solve?
Thread Starter
Drifting
Joined: May 2020
Posts: 1,663
Likes: 702
From: Baton Rouge, Louisiana, metro area
Thanks for the response.
No problem. My 91 is running perfect.
I am thinking of collecting a few harder to find parts and making a little stock for the future.
If I get a good computer now that I know is good, I will have one for a possible problem.
Just looking ahead.
No problem. My 91 is running perfect.
I am thinking of collecting a few harder to find parts and making a little stock for the future.
If I get a good computer now that I know is good, I will have one for a possible problem.
Just looking ahead.
