Link G4 RX Mock wiring Pin Out
 

Mocked up how I'm going to pin out the wiring for my Link, and figured I'd toss it out for some constructive criticism. This is my first wire in ECU so yell if I missed something simple:


ECU Pin - What's Connected - Note

Trigger 1 - Crank 1
Trigger 2 - Crank 2
Analogue Volt 1 - TPS
Analogue Volt 2 - See DI4 - Shared with DI4
Analogue Volt 3 - OMP
Analogue Volt 4 - Wideband
Analogue Temp Input 1 - Inlet Air Temp
Analogue Temp Input 2 - Engine Coolant Temp
+5V Out
+8V Out
Ignition 1 - Leading 1 & 2
Ignition 2 - Trailing 2
Ignition 3 - Trailing 1
Ignition 4 - Fuel Pump Relay
Injection 1 - Primary 1
Injection 2 - Primary 2
Injection 3 - Secondary 1
Injection 4 - Secondary 2
Auxiliary Output 1 - Boost Control Solenoid
Auxiliary Output 2 - ISC Solenoid
Auxiliary Output 3 - Fan
Auxiliary Output 4 - Tach
Auxiliary Output 5 - OMP
Auxiliary Output 6 - OMP
Auxiliary Output 7 - OMP
Auxiliary Output 8 - OMP
Digital Input 1 - Clutch
Digital Input 2 - Start
Digital Input 3 - Speed (VSS)
Digital Input 4 - Ethanol Sensor - Shared With AV2

Link has a wiring diagram available. Pg. 47 Great ECU BTW.
http://www.ak-motorsport.de/link/Link/G4Install.pdf

Yeah I based my pin-out off of what the current G4 Manual shows:

http://www.linkecu.com/support/docum...tion/G4Install

The one you posted is an older version that doesn't have the Pin out for the G4 RX. I'm just paranoid I might be missing something that would be detrimental to the operation of the engine.

You'd be surprised just how little stuff you actually have to have hooked up to get the engine running

Noticing that, my harness keeps getting thinner and thinner with stuff I don't need. Only thing I've noticed since posting the pin out is the lack of an output for the CEL. Not sure what I can swap out to make it work.

After giving it some thought I'm not going run the ISC solonoid on Aux Ouput 2 and instead use that output for my Check Engine Light.

Update 2: Will not be running the fans via ECU output but rather the ISC Solonoid.

i wouldnt bother with the engine check light as the link g4 has that many saftey features in it that if something goes wrong it can be set to drop half the power or completely shut everything down

Wildman, why not use the pinout they show for the plug and play version?

Plug and Play version uses the stock FD harness and the stock ECU encloser. The G4 RX has a wire in harness. The wire in was a better option for my build as I have this installed in my 95 Miata.

Figure I'd add screen shot of my excel sheet after I hunted down all the wiring colors from the FD harness, hopefully it helps out others. I am no expert at wiring so if something isn't correct please let me know so I can update as needed, use this at your own discretion.

http://i835.photobucket.com/albums/z...923/pinout.jpg

I also have a G4 RX wire in ECU, wound up getting it from the one guy you recommended. Thanks on that!

I'm actually being forced to rewire my complete FD, so I had to go this same wire in route, or I would of picked up the plug n' play.

However, if you bring up the LINK PDF for the plug n' play install: http://www.linkecu.com/support/docum...llation-manual They have a break down made up for the factory wiring. Check out page 18, section 7 in there. Pretty much what you've laid out with your excel sheet. Just give you a quick starting point.

Depending on your set up, few things you might want to look at.

Aren't the digital inputs for pulsed signal inputs? So your Clutch and Start Position Switch shouldn't be there as they are analog signals.

Your fuel pump relay should be controlled off your ignition switch, not your ECU.

Depending on your wide band, you may be able to run it as a digital signal, or analog signal. Same possibility with the Ethanol Sensor.

Gotta run, but your heading the right direction. I'll be starting my pin out as well in the next month.

Most important part, make sure you have good connections! No cheap plastic butt connectors :-)


Have always been under the impression the digital inputs are expecting either a ground (low) or 12v (high) signal, my clutch switch grounds and the start is 12v when cranking. Wideband is 0 - 5 volts just like the TPS. Weird thing is the Ethanol sensor is also 0-5 volts but as per the LinkECU.com forums it shows it needs to be connected to a digital input.

Correct, E85 sensors, at least the flex fuel sensors in GM, use a digital signal. While it is a 0-5V signal, the frequency of the signal changes depending on the ethanol content.

The majority of digital signals I see every day are 0-5V. Even so, most current ECMs actually range the 0-5V signal to a .5V-4.5V signal. That way the ECM can tell if your wire is shorted, the sensor is unplugged, ect. Your clutch signal going from 0-12V is not “digital”. It’s analog. Unless your clutch switch is sending a frequency, 0-12-0-12-0-12, when it’s pressed it’s analog. Your TPMS is analog, 0V – closed 5V- open, inbetween voltage can be calculated to a percent. Your Crank Sensor is digital! On off signal, the faster the engine spins, the faster the frequency of on off.

Your aftermarket sensors will do different things. You’ll need to check with where you got them from, and see the type of output.

Why should the ECU not control the Fuel Pump?

Connectors

EB Turbo

My personal point of view is that the ECM should be responsible for the engine, under the hood, and that's it. Everything else, leave to a body control module (I use the term module loosely here). This ECU only has so many programable outputs, why do I want to use one to run my fuel pump relay? I'd rather it run an intercooler sprayer based off a temp input. Hell even a flame thrower out the exhaust on boost would be better than a pump prime. Just run a relay off the ignition switch and it's all good. Plus, key is on, it primes and keeps priming :-) Who honestly puts the key in, waits for the prime then cranks? Maybe someone waiting for a glow plug to heat up. If you really care that much about the little 2 second prime, diode isolate a secondary control from a remote lock / unlock, so the pump primes before you even get in the car. No time to waist when I want to go!


Nice connectors :-) Complete with weather pack, that's fancy stuff! It's amazing the problems you'll get without it.

Pumps are ran off the ecm for a few main reasons but the most important is incase of a accident or rollover, the engine will either die or shut off thus killing the pump. If its controlled just through a switched power the pump may continue to stay on and become a very dangerous hazard. Also it doesn't just prime it, it primes with the key on and once it see's a crank signal it turns the pump on. As for the waiting for the pump to prime, try having bigger than factory fuel lines that don't fill up quite as quickly. I run two bosch 044's and -8 line and it takes a sec to get pressure at the engine.

+1:icon_tup:

OK, Safety, let see...How safe is your car to begin with from the factory? Not very. On that note, why would you drive it to that extent on the road? OK, so on the track, lets see, NHRA says that on a street legal EFI vehicle, fuel pump must shut off with the ignition key. Not the ECM. Every pro rally car and track car that was purpose built, has a switch for the fuel pump :-)

Say, OK, you wrap your car around a light post, and the engine stops. What are the odds that your relay is now crushed, and stuck? Or that wire is shorted? Will your car still run with a minor fuel leak? Yes it will! Maybe a mercury switch will help, have to get one of those!

Now, look at current safety systems. Your car sees a crash, it blows a fuse able link on your battery cable, everything dies but your flashers, your car calls for help, and probably makes you a cup of coffee while you wait.

How safe are your other "Mods"? Battery relocation is pretty popular on these things. Do you have a pyro link on your power cable? Probably not. So even if your ECM shuts off your pump, you'll probably have an electrical fire. How many people engine fire threads are on here?

So the difference between the ECM turning the pump on for a second, stoping, then turning it on when the crank starts to spin, VS open the door, pump turns on for a second, put the key pump goes car starts....is what?

If your that paranoid with the 1% what ifs, stay at home.

Sorry for jacking this thread.

lots of good info here.... thanks all for sharing

howard