Ecotec LNF swap wiring integration help (I think I am finally catching on)

I think I am finally catching on to how to wire up my ecotec LNF swap. 
 

Phase one was to wire up the bcm so that I can bypass the immobilizer, since you can not simply turn it off in HPtuners. I got that done. 
 

Next is to wire up so that the ignition in the car can start the lnf, and tell the fuel pump to turn on. 
 

My question is where do I wire the cars ignition to?  I can find wires at the ecu, bcm, and fuse block (all three from the donor lnf car) that seem to talk about starting the engine. 
 

From watching LS swap videos on you tube I am thinking that I need to wire it to the lnf fuse block?

Also in the picture below there is a symbol (see yellow arrow) that is showing two wires going into one wire is that correct? I just connect the tan and tan/blk wires from ecu to the green wire of the instrument panel cluster? 
 

I have the same question for how to have the lnf ecu tell the fuel pump in the car to turn on. 

Regarding yellow arrow.  GM is very nice with their diagrams, they tell you what every wire does and also give a circuit number.

The two wires are for the HIGH SPEED network.  High and low, which means they both have a 2.5v base voltage, the high goes high to signal a bit, the low goes low.

The green wire is for the LOW SPEED network.  It's a one wire deal because it doesn't need as much redundancy.

The diagram shows them because the networks are part of the charging system, in the sense that data must flow.  See how the BCM at the bottom of the diagram ALSO has the high speed CAN (er, GMLAN) lines?  That is how the PCM is communicating with the BCM.  It looks like the current sensor talks to the BCM, and then the BCM communicates that with the PCM to control the alternator.

Also note that the alternator light is controlled not by an external wire, but "serial data".

What you need to do is find the computer data lines diagram.  I forget what architecture GM uses, but I'm pretty sure that the high speed is a passthru kind of setup (wires start at one module, go to another module, a different pair of wires go from that module to the next one, until the end).   The low speed is, again pretty sure, wired with all modules in parallel, not in series like high speed.  The data lines diagram will be your friend.  But either the instrument cluster or the BCM will be the "gateway module" that high and low speed networks go through.

Leaving that post alone!  Regarding how to tell the PCM (err, ECM) to turn on the fuel pump.

You don't.  That is something IT controls.  It should do a short prime pulse key-on, and engage the pump when the ECM is turning the starter and when it has a valid crank signal.  ECM controls it.

I am bored at work waiting for parts, so I will poke around a bit.

Low speed GMLAN (what everyone else calls CAN) is a semi parallel kind of setup.  The radio, theft deterrent module, radio control door lock receiver, instrument panel, airbag SDM, datalink connector pin 1, and BCM pin 38 in X2 all share the same dark green wire (circuit 5060).  Additionally the radio receiver has its own wire to the BCM pin 18 in X1, and the vehicle communications module has its own in pin 36 in X1.

Parallel means you can cut any individual module out of the circuit and the network will still work.

The high speed GMLAN is in series.  All modules must be present or the in wires connected to the out wires with two caveats.  Both "ends" of the network must have a 120 ohm resistor.  If the modules do not see 60 ohms between the two wires, they assume the network is compromised.  Looking at the topography, the datalink connector (pins 6 and 14) go first to the power steering control module (contains a 120 ohm resistor), then to the BCM, then to the Driver Information Center, then to the VCIM if present, then the EBCM (ABS) if present, then to the TCM if present, then to the ECM, which contains the other 120 ohm resistor.

Not knowing what you are swapping into, and assuming you are only using the BCM and ECM, it looks like you bung the DLC to the BCM to the ECM and stick a 120 ohm resistor between the two wires somewhere between the DLC and the BCM.

In reply to Pete. (l33t FS) :

Thank you for all of that explanation, I think I am going to need to read it over a few times before it sinks into my brain. 
 

It seems like there is a lot more going on here than the "normal" ls swap wiring video I see on youtube. 
 

The explanation of series vs parallel helps a lot.  
 

I am using the LNF parts from the donor solstice: fuse box, BCM,ECM, and factory wire harness. 
 

It is getting swapped into my Mercedes 190e. 

https://grassrootsmotorsports.com/forum/build-projects-and-project-cars/operation-german-gamble-iaai-salvage-acution-190e/164851/page1/

I was hoping at this point after getting around the immobilizer, that it would be as easy as just wiring the Mercedes ignition cylinder and the Mercedes fuel pump wire to the solstice fues box , but now after reading your responses (thank you for those). It seems I have some more learning to do. 

In reply to frenchyd :

Pretty sure you didn't read his posts. He's not using the MB ECU. He's using the Solstice ECU. 

In reply to Somebeach (Forum Supporter) :

I'm curious to know why the immobilizer can't be turned off. I didn't have any issues tuning it out of the Solstice ECU, engine, and trans I used in the B210. I used an aftermarket harness though and didn't use the BCM. 

There may be some help here. https://forum.hptuners.com/showthread.php?88693-LNF-standalone-ECU-options

This reads like the BCM receives the key input and tells the ECU what position the key is in through the com wires. 

In reply to Toyman! :

Thanks for that link I will look at it a bit closer, I was just going off what the guy that I bought the swap parts from and a Facebook group said on how to set up the lnf swap in a different car. 
 

I am really still just trying to learn how to do all this stuff. 
 

Which ecotec did you use in your B210? The LE5? I think that it uses a different ECU than the LNF. 
 

On your swap how do you control the starting of the car? Are you using the stock B210 ignition cylinder? If so where did you wire that to? The solstice fuse block or the ecu? 

From the link above credit to kgschlosser:

"The BCM is attached to the key cylinder. the ECM is not, well not directly.

There is an ignition wire and an accessory wire that comes from the key cylinder to the BCM. the BCM watches these 2 wires to know what position you have the key in. When the key is turned to the start position the voltage on the accessory wire drops out leaving only the ignition wire hot. The only way the wires can be in this state is if the key has been turned to the start position. This is when the BCM checks the transponder code on the key. If the code is good the BCM tells the ECM to start, I will explain how this is done in a minute. the ECM is what cranks the starter. How the ECM knows when to disengage the starter is by using 2 mechanisms, The first is the voltage in the car. battery voltage is typically 12 ish volts, alternator voltage is 13.8ish volts. so when volts jump up it knows to stop cranking. What happens in the event of a bad alternator? The ECM also monitors the tach.

The physical act of turning the key to the start position only causes the voltage change on the wires to the BCM. It does not directly control the cranking. So you could sit there holding the key and the starter would disengage regardless.

OK so how does the BCM tell the ECM to run it's program for starting the vehicle??
There are 2 connectors on the ECM, they are labelled X1 and X2
There are going to be many wires that will need to be connected and I can tell you what needs to go where, we can do that in a PM if you like.

So the 2 wires I was speaking about.
Pin 41: Brown - Accessory Voltage
Pin 54: Pink - Ignition Voltage

The BCM controls the voltage to both of these wires. The BCM does not have to control the voltage to those wires. A normal ignition switch can take over that job. There is a wire that comes off the ECM that gets connected to the starter relay X2 Pin 57 - Pink/White, 
ECM also controls the field on the alternator, connector X1 Pin 30 - Gray Field Duty Cycle Signal (Pin B on alternator) and connector X1 Pin 10 - Orange Turn on signal (Pin C on alternator"

In reply to Somebeach (Forum Supporter) :

A lot of the weirdness you are running into is that modern vehicles properly have the modules do all of the heavy lifting current-wise.  The ignition switch passes no high current loads.  That way lies voltage drops and wear in the switch contacts.  The ignition switch merely passes low current signals to the modules, which then control devices either directly or through relays.

The start signal, for instance, just tells the PCM or ECM that you want to start the engine. It then powers up the starter relay.  Or not, if the engine is already running. Or the antitheft says no.  The flip side of this is that if it does NOT get a start signal from the ignition switch/what have you, the engine will not run.  Some cars cannot be bump started!  Learned that on a PT Cruiser with a manual trans and a bad starter.  It would only bump start if you had the ignition switch in the start position...

I have been running into this in the R53 that I am trying to put an MS3Pro into.  It controls relays by grounding the relay coil, per normal practice.  However, right there in TFM, it says that anything it controls can not have power with the ignition off, or stray voltage can leak into the computer and keep it from shutting off.  Well, practically everything in the car is constant power because the Mini was designed to have everything controlled by a module.  I don't WANT to have to cobble up a bunch of extraneous relays to invent some run/start-only feeds, because I want to avoid the Impenetrably Obtuse Mass of Poorly-Documented Spaghetti, but here we are...

In reply to Somebeach (Forum Supporter) :

Yes, I used the LE5. Using an aftermarket wiring harness made for the easy button. I used a toggle and a push button to the appropriate wires on the harness. 

I think you are going to have to deal with the BCU or figure out how to lie to the ECU.