GTO to Camaro Transplant Project

I’m transplanting a 2005 GTO Body Control Module and entire harness into an 1986 Camaro IROC with a GMPP 525hp LS3 and Tremec 6-speed.
I want to use the M2 to engage the A/C, performance mode and Cruise control functions.
If I can get this to work on mine I need to also do it on my dad’s 1993 chevy dually with a 2011 6.0L and I repinned the harness to use a E38 and the calibration off a different year silverado.

Quick question I would have for you is why?

You should be able to use the LS3 directly in the car if you use a carburetor system or if using a TPI for it there are many after market control systems available that will do all you want out of the box.

The Body control Module will do nothing for you and you would need a Powertrain Control Module. The M2 can talk to whatever modules you have but you then have to reverse engineer the items you want.

Not saying its impossible but just not sure why you would want to do something like this when there are complete systems already out there that do a better job.

Let me explain it better.
E38 ECU (2014 LS3 Camaro programming)
2005 GTO Body harness (BCM/PIM Can bus communication) BCM handles A/C input (talks to ECU for FAN control), performance mode (switches table changes in the ECU) and then communicates it via GMLAN. PIM handles Cruise function and talks to the ECU to handle electronic throttle.
NO TPI this is a LS3, no carburetor it is EFI.
I’m wanting to use the inputs on the M2, running Cruise, A/C and performance mode.
What system does this already?
I’m trying to eliminate the BCM and PIM since they don’t directly work with the 2014 programming and I don’t have the space for them in my dash.

So why are you using the BCM and PIM from a GTO?

Note that they are different modules and not the same module as it appears in the shop manual. The PIM talks to the Engine Control Module via CANBUS but talks to the BCM via J1850.

Trying to use the GTO modules will do you NO good unless they are able to interface into the ECM you are using. If you used the ECM from the GTO then maybe.

My shop manuals only go through 2009 so I can’t look up the 2014 Camaro but older vehicles just used a pin into the PCM to signal the high performance mode. On my '94 Caprice this was the case and was the same on the Camaro using the same PCM.

Your going to have a variety of issues trying to get that setup working. Do you have the pedals from a 2014 Camaro? I know both my '09 CTS and '03 Avalanche pedals are “drive by wire” and I assume the Camaro was the same requiring an input from pedals setup to talk to them with the TB having a motor on it controlled by the computer.

As far as A/C, that should be easy to do. You just need to read the AC pressure switch and if it is OK then you can turn on the clutch when AC is called for. There may be something such as a change to the minimum idle and if you have electric fans then one of them will likely be turned on. Best solution for this is to get a shop manual for the car its going into that has the wire diagrams so you can double check everything.

Cruise control might be a little tricky. You may have to reverse engineer a Camaro to see how it is applied. If it sends a request to the ECU or if it is controlled manually by the BCM. Should be able to be controlled by the M2 but will require some reverse engineering as mentioned.

Seems like I have run across an after market engine control system that supported AC. The Cruise control may be something you manually have to do and the Performance stuff would be something the control system would have to support as well.

The use of the GTO config was for the Daytime Running Lights, Auto Headlight, wiring that had the FM/GSM antenna pre-amp and a larger fuse panel with the integrated relays to handle interior/key switch functions.
The more I talk and read what you had I know it will be a bit of a 'long road". I will have to get a 2014 bcm just to interrogate the CAN bus to see signal input to switching for their assigned hex key to know how to program the M2 and what it needs to send out in regard to the given input.
I know there are 6 Analog inputs (using 4, one constant, 3 momentary), I hadn’t had a lot of time to look further, but based on a 0 or 12V input can I output a 1 or 4 volt signal to simulate the Clutch Pedal Position? I’ve been told that the cruise will not engage unless I had a CPP signal at 1 or 4V and if the M2 can handle it would be cool. Otherwise I was going to run a 0/12V to a Micro relay and put resistors on the output leg to simulate the signal, but use the base 12V and adjust to run it through a 1/8W resistor to tell the 2014 E38 Camaro that it was present.
My diagram shows that the GMLan is run through the PIM, GTO BCM talks on CanBus to PIM only and I’m assuming that it translates to the ECU. I have no can bus in my schematics going to the ECM. I’ll go back and look. The PIM does handle the cruise function on GTO btw (worthless to me)
The E40 (GTO)is a weird config…

This should have its own thread… Maybe Moderator can split it off?

Picture #1 from GTO DLC schematic

Picture #2 from GTO DLC schematic

Note that High Speed GMLan means CANBUS, GTO doesn’t have the SWCAN

Note that the UART Serial is J1850 as mentioned elsewhere in the manual. I knew the IP was J1850 from some other research I have done in the past so makes sense. They basically use Canbus ONLY for the engine controls.

When looking at the connectors for the BCM there are NO canbus connections. This is similar to the 2006 GM trucks. They had CANBUS ONLY for engine and transmission controls also and J1850 for everything else.

As to the rest of why your using the GTO stuff. I am not sure why your trying to do all that with an '84 vehicle. If you want to go that route your almost better off grabbing the wire harness from a 2014 Camero and try to integrate into the car since it is all programmed to work together. Then you just have to fool it to think its in a 2014 Camaro instead of a vehicle 30 years older. You could still use the M2 at that point but Strongly suggest if your going to go this route to get a harness from a car compatible with your ECU. Or go with a different ECU that you will have better luck with. Maybe from a GTO…


2014 Camaro BCM - JST Header with X1-7 terminals in 0.64 - 2.8 7 different varient’s based on wire size and current capability. I called in for pricing on the handframe and jaw set. (2 days to hear back from mouser).

At this point I think it would be easier to the ECM, figure out the addressing and run the GTO BCM standalone…
Too much to do to make the Cruise work through the 2014 Camaro BCM. I like challenges but this may be getting out of hand. Maybe after I have the car running I will work on integrating other components.

GTO Interior Fuse/Relay Module with IROC dash mount attached

GTO Engine Fuse/Relay module mounted in my IROC. That is a the GMPP E67 which will be used to start it but has none of the options enabled for cruise or performance mode. I think the fans will cycle correctly based on the A/C PSI but not sure of that yet either.

2005 GTO BCM mounted in IROC Dash @ the original ECU location

Finally remembered to move this to its own topic. Any updates @gixxer92?

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Thanks for moving this into it’s own thread ECSharpe and sorry I haven’t been on for a while. I’ve actually completed a second LS transplant and have a wire job coming up on a 3rd LS swap I’m doing.
The car is out for bodywork and paint right now and when it comes back I plan to start working with the hardware and making things work through the GMLan.
I did see that GM is coming out in the next year if not on the 2019’s with ethernet communication! This is exciting but I don’t know if i can make the newer ECU work with the LS3, but I may attempt…