I just got my first LS1 car. I bought it as a roller with no motor or trans. It is a 1998 Trans Am, A4.

I just purchased a complete 2000 LS1/T56 dropout to use in this car. Being the car was an A4 and I am swapping it over to M6, I would like to just use the 2000 engine harness and PCM.

I am new to the LS1 scene but not new to the fourth gen f body at all. What do I need to do to use the 2000 harness and PCM in my 1998 car? Will it be plug and play or will some changed be made? I could always just find a 1998 M6 harness but I already have this stuff.


Input, advice, information please? Thanks!




I also posted this in Gen III external engine but pretty much had no luck whatsoever. Hopefully this is a better section for this type of question.

 

Does anyone have any idea where I can find this info? I am somewhat amazed that I have not gotten a response yet. Should I try the swap/hybrid forum?

 

The cluster is different you'll have to run a 99 & up to make it work with the 00 pcm.
I'm betting there's more to than just that though.

 

I am utterly amazed that I cannot find this info.

 

Here's what I know:

If you use the 2000 engine, harness, T56, & PCM, all together, then that side of it will be OK. You must use the 2000 enigine sensors w/ the 2000 PCM, nothing from the 98 engine compartment. All sensors are different including the coolant temp used for the fans.

The area in question is the BCM side, gauges mostly. If you have tuning software, you may be able to change the pulse signal to the tach & speedo in order to get them to work. Don't know about fuel level, temp gauge & warning lights. My experience in swapping has been that the BCM & hard wired side of the roller stays with the car. You will probably have to hook it up & see what happens. The engine controls will be fine. You will just have to play around with the gauges...etc..

 

its the biggest pita swap easier to put a ls2 in LOL.. you need to switch everything under hood just drop and swap cradels with everything. inside you need the dash harness from pcm to cluster and cluster.

You should buy the 98 engine or buy another car 01-02 if you want to make your life easier

 

All sensors are the same with the exception of the 3 wire temp sensor on the '98. The third wire directly drives the temp gauge, instead of the pcm delivering a not very helpful cold/warm/hot signal to the gauge.

Gauge feeds on the '98 are individual analog signals. Gauge feeds on the 99+ are serial data over Class 2 data line.

I haven't researched what it would take to support the swap, even though I considered it before I committed to a 2-bar sd tune on my '98. Definitely the gauge cluster, and whatever portions of the interior harness that go from the three white pcm connectors under the passenger side of the dash to the cluster.

If it extends to changing the BCM, then it could branch to other systems in the car and affect more wiring (since the BCM is tied into the radio, lighting, windows, etc.)

 

i would contact DOC at EFI Alchemy,

I beleive the swap can be done, just rewiring the 2 or 3 connectors under the dash to use the 2000 engine harness, I would add a wire and continue using the 1998 temp sensor, so you have an accurate temp gauge.

You will have to use EFI Live to do a fuel segment swap, to make the newer ECM output to the older fuel gauge. You may have to run a couple of wires from the ECM to the inner harness connectors.

Ryan

 

Good point, I forgot about the 2 different ohm ranges on the fuel sending unit for 98 vs. 99+.

 

Now that's what I'm talking about! Thanks for the info guys. Sounds like I better just find a '98 harness. I already have a '98 A4 harness and PCM, but need M6 stuff.

 

Some of us helped you out man..

 

I put my car together from parts out of three different Camaros and used a 98 body with the 98 tank but swapped the 2000 engine and interior harnesses in. Everything worked except the gauge cluster and the wiper motor. After swapping those Everything worked right.

Good luck, Tom

 

Interesting project. Two very distinct mods here. First for the A4- M6 swap I would suggest selling your 00 A4 harness and getting a 99-02 M6 harness for simplicity.

Second, for the 98 upgrade slow (Ryan), mentioned the three body to engine harness connectors on the 98 car side. They are C210, C220, & C230. You are going to have to consolidate C210 into C220 & C230 as the 99+up engine harness' only have the two connectors.

In order to avoid changing the cluster and all that jazz to get the fuel gage to work, using EFI Live will allow you to swap fuel segments in the software.

I've done the 98 swap in every imaginable way, starting out with my own car years ago. This was prior to the segment swap revolution....Yes, there are 35 wires behind the instrument cluster on the 98 and only 17 on the 99+up.

 

I think he has a 2000 6 speed harness already, or that is how I understood it.

Ryan

 

Yea, that's the way I'm reading it too..

 

Re-read; yep. We can set you up with EFI Live, & a pcm with the software and tune already setup. Let us know.

 

So in other words you are saying all I have to do is consolidate C210 into C220 & C230 on the body harness, and have things fixed in my PCM with EFI Live for my gauges to work right?

Yes, I do already have a 2000 M6 harness and PCM.

 

Yep, you got it.

 

I just compared the connectors where the engine harness connects to the dash harness and it seems that just about every wire in those two connectors is different. Where do I go as far as that? I really don't want to change the dash harness.

Would you mind shooting me a PM with a little guidance if you have time, Doc? Thanks

 

PM sent.