Wiring question?

[CokeZero]

I was just reading into canbus stuff because I’m LS swapping my brz. It seems like a huge headache.

I had planned to run both the brz oem computers to control all factory stuff like lights ac abs ps windows all that good stuff and I was going to run the ls oem ecu with a stand alone harness to run the engine stuff. I know I would have to do something special to get the factory gauges working but that’s all I thought?

[spitsnaugle]

Originally Posted by CokeZero

I was just reading into canbus stuff because I’m LS swapping my brz. It seems like a huge headache.

I had planned to run both the brz oem computers to control all factory stuff like lights ac abs ps windows all that good stuff and I was going to run the ls oem ecu with a stand alone harness to run the engine stuff. I know I would have to do something special to get the factory gauges working but that’s all I thought?

to run AC and Cruise Control right now your option is to go PureAutomotive Motec & pnp harness.

Colin @ MRS electronics is working on getting it to work with with our cars via his canbus module, using my car as a development mule, but I cant speak to when or if it'll work.

If youre still going the canbus module route, get a stand alone LS harness, from something like SpearTech or WiringSpecialities, then see my post #51 here for some wiring help: http://www.ft86club.com/forums/showt...=128216&page=2

[wutsaiu]

Good luck.

[CokeZero]

I don’t understand how that won’t work? Why can’t I have the factory car stuff ran from it’s own computer like the signals lights radio and all of that and just use the ls ecu with its own harness to run the engine and anything else motor related?

Also I need to get my cars oem computer programmed because I replaced security stuff and it doesn’t start right now. If I HAVE to ditch the stock unit should I just forget that? Because the Toyota dealer in my town said they can’t reprogram it and Subaru dealer is a few towns over.

[spitsnaugle]

Originally Posted by wutsaiu

I don’t think dual ecu setups are common. Every setup I’ve seen is either a fancy ecu like motec or basic standalone with canbus module like MRS or arduino. I have seen no documented setups that actually make use of the stock ecu. I pulled mine out and chucked it.

Standalone + MRS is usually dual ecu setup

Originally Posted by CokeZero

1. I don’t understand how that won’t work? Why can’t I have the factory car stuff ran from it’s own computer like the signals lights radio and all of that and just use the ls ecu with its own harness to run the engine and anything else motor related?

2. Also I need to get my cars oem computer programmed because I replaced security stuff and it doesn’t start right now. If I HAVE to ditch the stock unit should I just forget that? Because the Toyota dealer in my town said they can’t reprogram it and Subaru dealer is a few towns over.

1. The factory Subaru computer will handle most everything OUTSIDE of the engine-- BUT AC and cruise control are controlled by the GM or aftermarket ECU is controlling the engine because -- for AC it'll need to activate the fans and increase idle speed -- and Cruise will need to modulate the throttle. So that needs to be communicated by some more intricate canbus work than is currently available (again being worked on by MRS electronics- but no guarantees from me) or a new, more capable ECU (IE Motec).

2. You do not need to have the subaru ECU reprogrammed to my knowledge. I did not need to with my stand-alone setup with my FRS.

[Sportsguy83]

Originally Posted by CokeZero

I don’t understand how that won’t work? Why can’t I have the factory car stuff ran from it’s own computer like the signals lights radio and all of that and just use the ls ecu with its own harness to run the engine and anything else motor related?

Also I need to get my cars oem computer programmed because I replaced security stuff and it doesn’t start right now. If I HAVE to ditch the stock unit should I just forget that? Because the Toyota dealer in my town said they can’t reprogram it and Subaru dealer is a few towns over.

The factory dash communicates with the engine via Canbus. The canbus communications are used throughout the car systems (ABS, PS, CC, Dash, etc..) in order to report accurate information (basically to work). Furthermore, some of those systems use engine sensors communicating via canbus to work. Because of this, this is not a swap like it happened in the past, where you could just control the engine apart from the car systems and they would just work. The canbus system needs some integration between both parts. This is where a canbus translator or standalone ECU is required to get these systems to function properly.

Yes, some stuff works aside from canbus integration. But CC, PS, Dash, AC, ABS, among others, all need canbus communication to function.

If you go standalone, you won't need the factory ECU at all. I don't know if MRS canbus passes through the security information from the stock ECU or if you can also disregard it, but with the MRS canbus you do need the factory ECU plugged in.

[CokeZero]

Basically I just want the push to start to work, the AC and ABS to work. The dash to work. Couldn’t care less about cruise or anything else

[spitfire481]

That's pretty much everything unfortunately. ABS module, body control module, keyless module, ecu (or a standalone that is talking the right canbus language), cluster all have to be talking and happy for everything to work and not error out.

[Zer0]

Originally Posted by spitfire481

That's pretty much everything unfortunately. ABS module, body control module, keyless module, ecu (or a standalone that is talking the right canbus language), cluster all have to be talking and happy for everything to work and not error out.

Do you guys know any shops that have done a complete rewire to remove the can bus system?
I'm looking to keep power windows door locks, and lights. Power steering may be handled with a module and stock motor or aftermarket electric power steering.
I will just run a custom harness and a GM ecu for the engine.

I want to use a power distribution module to eliminate the fuse blocks and relays as well. Gain some room loose some weight.

[spitfire481]

Originally Posted by Zer0

Do you guys know any shops that have done a complete rewire to remove the can bus system?
I'm looking to keep power windows door locks, and lights. Power steering may be handled with a module and stock motor or aftermarket electric power steering.
I will just run a custom harness and a GM ecu for the engine.

I want to use a power distribution module to eliminate the fuse blocks and relays as well. Gain some room loose some weight.

our racecar has nothing but a custom harness and a motec pdm/keypad in it. none of the things you are looking for still work or are installed though.

[Zer0]

Thanks for the reply. Looks like I may be on my own going this route.

[geraldjust]

Originally Posted by Zer0

Thanks for the reply. Looks like I may be on my own going this route.

Since you got push start it will get a bit more complicated. I think MRS controller passes though security stuff though canbus so the use of the factory ecu will be needed for push start. IF you want everything to work go with the motec option.

If you want important creature formorts to work use MRS. But not sure if he has AC working. He has support for push start. but you need to keep your factory ECU.

[Zer0]

Im removing so many components. I think it's better to do a complete rewire on the car.

[spitfire481]

Originally Posted by Zer0

Im removing so many components. I think it's better to do a complete rewire on the car.

thats what we did on our green car. much nicer in the end