Getting an engine and wiring harness out of a Tribeca for my XT6, the engine harness goes to the interior and splits, one section to the ECU and the other going up somewhere. Where does this go, does it connect to the rest of the car and if so can I just cut it? I’m guessing something that it goes to is the OBD2 connector, is there some alternative to taking the whole harness? I’m trying to remove everything from the harness that isn’t connected to the engine/ECU.

Basically my questions are:

1. Where does that wire go

2. Does it go to a connector or will I have to cut it

3. Is it connected to anything that’s required for the engine and diagnostic system to work (other than the OBD2 port which I can figure out)

Another thing I thought of: Will OBD2 work if I have just the ECU, not the other stuff?

Don't even bother with the factory ECU. You'll likely never get the immobilizer to function. It requires the BIU, the gauge cluster, the transponder key, and the ECU to be married and present. All communication is via CANBUS and without the TCU and all the other controllers you will have no end of fault codes. It will be an absolute nightmare. Also these engines are drive by wire so you need the accelerator pedal, harness connector, etc, etc. 

That's not how this is done. We do swaps all the time......

Run the engine with a LINK standalone. https://linkecu.com/

GD

Edited July 21, 20232 yr by GeneralDisorder

9 hours ago, GeneralDisorder said:

Don't even bother with the factory ECU. You'll likely never get the immobilizer to function. It requires the BIU, the gauge cluster, the transponder key, and the ECU to be married and present. All communication is via CANBUS and without the TCU and all the other controllers you will have no end of fault codes. It will be an absolute nightmare. Also these engines are drive by wire so you need the accelerator pedal, harness connector, etc, etc. 

That's not how this is done. We do swaps all the time......

Run the engine with a LINK standalone. https://linkecu.com/

GD

I would use a standalone but I live in California so I would need to use the stock ECU at least for smog checks

1 hour ago, linkthehero1234 said:

I would use a standalone but I live in California so I would need to use the stock ECU at least for smog checks

Not gonna happen..... you'll never get all of the systems installed into the vehicle to satisfy the ECU's emissions systems requirements and immobilizer, etc. For a smog check you can't have ANY diagnostic codes - the ECU wants all the other computers it talks to in the Tribeca - TCU, ABS, BIU, gauge cluster, transponder key, and likely several more. And all of the those computers have to be happy also or they will send a message to the ECU for a "MIL request" - which will illuminate the check engine lamp, disable cruise control, etc. You would need the entire fuel system and evaporative emissions system from the Tribeca..... you basically would have to transplant the entire drivetrain and every single bit of wiring which would be a herculean effort. You're better off with something like a first gen EJ22 swap where the ECU is extremely dumb and has no OBD-II capabilities. 

And yes - California sucks. Highly suggest leaving the Soviet Socialist Republic of CA. I won't even visit that state and I'm in Oregon. I just drive around that hell hole. 

GD

Edited July 21, 20232 yr by GeneralDisorder

Yea, being a CANBUS car, you would have to get Every. Single. Module. in the whole car. And you have to make every single one happy. Or none of it will function.

 

The most current information you'll find will be on the "Six Swapped Subarus" Facebook group. If someone's figured out how to crack one of the ECUs, it'll be there. But if the software's been modified, it likely still won't pass smog.

I’ve also seen that people use CANbus emulators for these types of swaps, is it possible to DIY one for when I have to get a smog check then switch to a standalone? Or will I have to buy a prebuilt emulator?

Anything is possible with enough engineering knowledge and time and a CANBUS sniffer. You have this experience and knowledge or money to pay for it? It smells like no since if you did you literally wouldn't need to ask these questions. 

One thing you cannot get around in the state of CA is that they are now doing checksum calculations of the original software on the ECU so even if you were able to make changes with a Tactrix cable such as disabling the immobilizer system, etc - it wouldn't pass smog because changing even a single bit value of the original code would change the checksum and it would fail due to software tampering.

iWire is located in CA and could advise you on the particulars. Don't be surprised if this is economically unfeasible - you essentially have to recreate the Tribeca in a software emulation just to get the engine computer to be happy enough to pass a government mandated 30 second inspection. You really want to do that? F*ck that state in my opinion. Register the car in Utah or one of the other states used by https://www.dirtlegal.com/

https://iwireusa.com/blogs/iwire-university/canbus-part-2-can-bus-and-your-subaru-swap

GD

That might be possible, but you'd have to reverse engineer all the information on the CAN data stream, and then begin to experiment to see what the ECU needs to run without throwing codes. Frankly, the fact that you're asking these questions means you probably aren't up to the task, it requires several orders of magnitude more knowledge of the car and it's systems than knowing which harness goes where.

AFAIK, there is no "prebuilt" emulator to do this. There are prebuilt universal emulators/loggers, but they'd likely have to be custom programmed.