ccrane0044

Hey guys,

I will be replacing the current LY6 engine I have swapped into my Cutlass with a LS3 engine. What I am wondering and hoping to get some help with is the harness differences between the truck harness I used and the LS3 harness.

I assume there will be a difference with the cam sensor since the LS3 is not a VVT engine and I also heard something about the MAP sensor as well. I was hoping someone could confirm this point me in the right direction as to what may be the easiest way to go about making this work. Are there any harness adapters for this or possibly have GM part numbers for the connectors?

Thanks in advance,

Calvin

clinebarger

If the MAP sensor plug is different?......You will need some tuning to run the LS3 MAP sensor.
https://www.summitracing.com/tx/part...rese1-_-holley Sales for about as much as a pigtail.

This will fit the Camshaft Sensor Jumper Harness.....Remember Gen IV's are wired backward from Gen III's.
https://www.summitracing.com/tx/part...1-_-ict-billet

ccrane0044

Thanks for the reply Clinebarger

The LY6 engine and harness I have is a Gen IV engine. I will be changing the tune to a LS3 tune instead of the LY6 tune that I currently have.

From what I can tell the Camshaft Position Sensor connectors for both engines are ACDELCO Part# PT2785 so I'm assuming that connector wont be an issue which I am a bit surprised about, maybe someone can confirm this for me in case I am incorrect. The MAP sensors are different along with the connections so my plan is to purchase a new connector pigtail and wire that in to my harness. As far as I can tell all the other connections seem the same but was hoping someone else may be able to confirm this.

clinebarger

My LS3 timing cover came with a 3-pin CMP sensor plug, The original L92/VVT cover took the 5-pin PT2785.

ccrane0044

O kk so I'm assuming I will have to buy that connection as well. The 5 pin is probably for the L99 I'm assuming.

Do you happen to know if those 3 wires are pins 44 (A), 66 (B), and 64 (C) from the ECM? If so I gather pins 16 and 52 are the extra wires that wouldn't be used for the 3 pin connector.

clinebarger

That is correct for a E38 ECM.

ccrane0044

Awesome, thanks clinebarger!

Do you happen to know of any other sensor differences or would it just be those two?

clinebarger

Not that I can think of, Of coarse you probably know that "truck" harnesses don't fit "car" intakes very well as far as aesthetics is concerned?

ccrane0044

Thanks for the help Clinebarger!


For future reference if anyone else wants to do a similar swap. The CAM sensor, the MAP sensor and the Oil Pressure sensors are different between the harnesses.