98' to 99' and up PCM question
01-16-2019, 08:24 AM
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98' to 99' and up PCM question So I have searched and found some threads about this topic and repining harnesses, etc. these posts talk about how complex it is and how in order to have an operational fuel gauge you have to do additional complicated work.
My situation is a little different, my 98' Z28 is a roller, and has no harness. I have found a company that offers a 98' to 02' PCM swap kit which includes the following: Proper setup for 98 fuel gauges, setup for selected transmission, rear end ratio, tire size, and coded to VIN.
My thought is because the PCM will be coded to my VIN, I shouldn't have to worry about VATS delete until my "real" tune, and I shouldn't have to repin the harness because I can just source a 99+ harness from a Tahoe? Does that sound correct, anything else to worry about? I need a PCM and harness either way, this seems like a decent option to end up with an 0411 PCM without the headache in a 98'.
My situation is a little different, my 98' Z28 is a roller, and has no harness. I have found a company that offers a 98' to 02' PCM swap kit which includes the following: Proper setup for 98 fuel gauges, setup for selected transmission, rear end ratio, tire size, and coded to VIN.
My thought is because the PCM will be coded to my VIN, I shouldn't have to worry about VATS delete until my "real" tune, and I shouldn't have to repin the harness because I can just source a 99+ harness from a Tahoe? Does that sound correct, anything else to worry about? I need a PCM and harness either way, this seems like a decent option to end up with an 0411 PCM without the headache in a 98'.
01-17-2019, 01:53 PM
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Edit:
Continued to search it appears any 99+ LS engine harness will work with the PCM since these harnesses used 411 PCM, however, the one issue I have uncovered so far is that the 98' cluster displays the coolant temp directly from the sensor which is a three wire sensor and the 99+ harness is for a 2 wire sensor so at minimum the sensor needs to be upgraded. Still tryin to figure out how to work around to display the coolant temp on the cluster.
Last edited by KansasZ28; 01-17-2019 at 02:45 PM. Reason: New Info.
01-17-2019, 03:27 PM
#5
I read your post, a truck harness will NOT plug into a 98 f body body harness. A 98 has 3 plugs that plug into the car on the passenger side floor board, a 99 fbody harness or a truck harness will not have the correct plugs. Anyone who sells tunes and pcms can sell you a 896/411 pcm setup to work with a 98 thats not the issue, we done tons of them. You can re-pin a 98 harness to work with a 896/411 pcm or use a 99 f body engine and body harness along with a 99 cluster.
With enough re-pinning and re-wiring you can make anything work in theory, if its worth it would be the question, essentially you would be rebuilding the whole harness.
With enough re-pinning and re-wiring you can make anything work in theory, if its worth it would be the question, essentially you would be rebuilding the whole harness.
01-17-2019, 06:49 PM
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I read your post, a truck harness will NOT plug into a 98 f body body harness. A 98 has 3 plugs that plug into the car on the passenger side floor board, a 99 fbody harness or a truck harness will not have the correct plugs. Anyone who sells tunes and pcms can sell you a 896/411 pcm setup to work with a 98 thats not the issue, we done tons of them. You can re-pin a 98 harness to work with a 896/411 pcm or use a 99 f body engine and body harness along with a 99 cluster.
With enough re-pinning and re-wiring you can make anything work in theory, if its worth it would be the question, essentially you would be rebuilding the whole harness.
With enough re-pinning and re-wiring you can make anything work in theory, if its worth it would be the question, essentially you would be rebuilding the whole harness.
01-18-2019, 07:50 AM
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LSX Power Tuning confirmed that the f-body body harness has three connectors and the truck engine harness won't connect. However, from searching it seems like people have used 99+ f-body engine harness and the only issue that I have found was that the 98' uses a three wire coolant temp sensor, and the 99+ use a two wire. I haven't seen anything stating you have to upgrade body harness and cluster, only that you have to have the correct fuel segment tables for the fuel gauge to read the fuel level.
01-18-2019, 08:15 AM
#9
I read your post, a truck harness will NOT plug into a 98 f body body harness. A 98 has 3 plugs that plug into the car on the passenger side floor board, a 99 fbody harness or a truck harness will not have the correct plugs. Anyone who sells tunes and pcms can sell you a 896/411 pcm setup to work with a 98 thats not the issue, we done tons of them. You can re-pin a 98 harness to work with a 896/411 pcm or use a 99 f body engine and body harness along with a 99 cluster.
With enough re-pinning and re-wiring you can make anything work in theory, if its worth it would be the question, essentially you would be rebuilding the whole harness.
With enough re-pinning and re-wiring you can make anything work in theory, if its worth it would be the question, essentially you would be rebuilding the whole harness.
This is what I can't get a definitive answer on...
LSX Power Tuning confirmed that the f-body body harness has three connectors and the truck engine harness won't connect. However, from searching it seems like people have used 99+ f-body engine harness and the only issue that I have found was that the 98' uses a three wire coolant temp sensor, and the 99+ use a two wire. I haven't seen anything stating you have to upgrade body harness and cluster, only that you have to have the correct fuel segment tables for the fuel gauge to read the fuel level.
LSX Power Tuning confirmed that the f-body body harness has three connectors and the truck engine harness won't connect. However, from searching it seems like people have used 99+ f-body engine harness and the only issue that I have found was that the 98' uses a three wire coolant temp sensor, and the 99+ use a two wire. I haven't seen anything stating you have to upgrade body harness and cluster, only that you have to have the correct fuel segment tables for the fuel gauge to read the fuel level.
01-18-2019, 09:07 AM
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Back to the drawing board... I found a 99' Trans Am PCM and harness last night for a decent price and attempted to pick it up, but didn't get a response from the seller (guess I lucked out.) Looks like I will focus on finding a 98' harness and using the rest of the Chicago winter to take my time and label connectors and then re-pin. Thanks for everyone for the responses and help.
01-18-2019, 10:51 AM
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It's too cold right now to work on the engine in the non-heated garage, but I can sit in my basement and go through the red/blue connectors with a guide. This will at least help me make some sort of progress, so that hopefully things speed up when the weather starts to warm up.