Mixing Donors

[n175fs]

I have a 08 5 speed LS low mile donor but the body wire harness is messed up bad. I can get a 06 auto trans LS donor cheep. Is it possible to adapt the 06 harness to the 08 engine? It hard to find 5 speed cars in my area.

 

[Brian74]

I don’t think they changed much on the LS between those years but you may want to go through all of the BCM and instrument panel pinouts with both wiring diagrams to be sure. There may be some slight differences in VATS and in the instrument cluster, and possibly the fuel pump. A lot of stuff that may be different will be thinned from the harness anyways.

 

[JSATX]

The computer was changed in 08. There very well may be different plugs between those years

 

[n175fs]

I verified you are correct Justin. So I guess my question is can I use the 06 ECM (automatic transmission car) on my 08 standard transmission engine? Is there any logic in the ECM program that communicants with the AT control module?

 

[JSATX]

I verified you are correct Justin. So I guess my question is can I use the 06 ECM (automatic transmission car) on my 08 standard transmission engine? Is there any logic in the ECM program that communicants with the AT control module?

No, you almost certainly couldn’t do that. Even if they were of the same year the auto and manual have significantly different software

 

[Brian74]

I don’t know what changed in the ECM in those years on the LS. I am currently converting an 06 SS body harness to work in an 09 SS. I am
having to use a different (bosch) ECM connector and doing a full repin on it. I am also using a matching 09 BCM. The BCM connectors are all the same, but I think a couple of the pins may need to be swapped.

 

[n175fs]

Thank you Justin. I figured there might be an auto / manual interface issue. Time to fire up the search engine!

 

[Brian74]

If you’re questioning whether auto or manual ECM’s are compatible, you may want to just stick with the same year/generation and transmission harness to keep things simple. There is nothing easy about converting it whatsoever unless you truly know what you are doing.

 

[RichRich]

I have had a hand in trying a different year harness against a same make/model car and it was not working, like Brian said earlier it probably required a complete re-pin and that wasn't anything we were willing to do. Be leery when using harnesses and and engines from different years