I consider myself as mechanically inclined, so for me it was pretty easy. On a scale of 1-10 it was a 3.

Now if u had no idea what wire clippers were or what a Philips screw driver is it might be a 7-8 for you, but its really an easy process as long as you take your time and pay attention.

There are 6 wires which you need to use and a last auxiliary one (blue wire) where I hooked up to GS42NV’s O2 sensor so he could monitor that is he also wanted to.

Power = Red
TPS = Gray
Ground = Brown
Ground = Black
A/F signal out = Yellow
A/F signal in = White
Tach/RPM = Green
* O2 sensor = Blue

***MAKE SURE YOU USE THE HOTWIRE TYPE CONNECTION METHOD ANYTHING ELSE WILL NOT WORK AND MAY CAUSE ENGINE FAILURE****




So now here is a picture of the ecu, You will find the Ecu box right to the right of the radiator. So if you are facing the engine, you look down and directly in front of you is the radiator and to the right about 6 inches to the right and 5 inches up you will see the box. (Before you do anything else UN PLUG THE BATTERY!!!)

Now before I started to wire up the safc wires to the ECU I ran the wires thru the firewall, this gives you the flexibility of not having the wires attaches at one end so u can fish them thru easily. Grab a wire coat hanger from your closet and unravel the wire, straighten it out and use this to fish the wires thru the narrow opening in the firewall.
Use some tape to tape the coat hanger wire to the safc wires, I used electrical tape and just started from half way down the coat hanger wire all the way to the other half of the safc wires just to be safe. Then from under the drivers kick panel I located the rubber boot in the corner near the fuse box. I grabbed a huge 10 inch long flat head screw driver and after about a minute of poking around I was able to get the head of the crew driver out to the engine bay, once this was done I left it in place and snaked the coat hanger wire thru the newly created hole I had made and kept open with the screw driver.
Once the coat hanger wire went thru it was a piece of cake. I just went to the engine bay and pulled the coat hanger which had the safc wires tapped to it thru the hole and ta daa that parts done!!


Unscrew the three screws to the box and once the cap is off you can basically see the ecu shown in the diagrams below






Next I took unplugged all the connectors to the ecu and one by one I took my time and located each wire… Imagine you are playing battle ship, lol. I use a grid pattern and try to locate the appropriate wires in that matter. Ie 4 down and 2 over or 2nd row and fourth over.
Once you locate the wires, check and double check that you have the right wires grab one of these splices shown below; ( you can buy them at any radio shack or electronics store)







And splice the wires from your safc into the appropriate ecu wire, Make sure the metal pin goes all the way thru and then snap the retainer clip on. I like to yank the wires a little bit after I have finished each one just to be sure.

** MAKE SURE YOU INSTALL THE BROWN AND BLACK WIRES EXACTLY AS SHOWN ON THE ABOVE DIAGRAM****




Then it just comes to where you want to install it. I installed GS42NV’s in his ash tray and that just requires you to dremel out the plastic in the ashtray enough for the safc to fit. And just run the wires thru the back of the carpeting to the drivers side kick panel.


Hope this helps people!! If you need anything else ley me know!

 

nice write up. thanks

 

When you say you use the blue wire for the O2, how do you read it on the SAFC?

Edit: For a second there I was confused, I thought you were using the SAFC to read the O2 sensor like a wideband, but its just for voltage.

 

Nice write-up, I think I will try this myself. I'll try most anything if there's a write-up about it and it's not too hard. By the way what is the 'HOTWIRE TYPE CONNECTION METHOD'?

 

Its a setting in the SAFC itself. Go to www.apexi-usa.com to see how to do an initial setup after you install it. When you go to the site just look up the instruction manual if you dont buy a brand new one.

 

Nice write-up. The only thing I wouldn't suggest is using the retainer clips. On my old car I found that soldering the wires worked 100x better and gave a much clearer signal rather than just using the clamps.

 

Very nice

 

Hey didn't even credit me with that diagram!!! Yeah that last diagram I made thank you very much. Always solder all your connections folks. I never use those taps.

 

FYI,you have to use a different diagram for the 430 motor.

 

is it the same for the first gen SAFC?

 

That diagram 10e is the same for 1at and 2nd S-AFC. the S-AFC II added the knock sensor wires. (for GS400 only.)

 

Thanks for the detailed DIY instructions Steve!

The only confusion I have with the instructions is this part:

How do you know which wires they are? What am I missing here? Please clear this up for me.

I will be trying this out myself in the next 2 or 3 weeks as soon as it gets warm enough!

 

Hameed,

I am not understanding your question.

Above he supplied both the ECU color wiring and also the SAFC color wiring. So between the 2 you can match which wires go to which. Make sense?

Also, as other people have said. Don't use the taps. Solder all connections. I have installed an SAFC 4 times so I am speaking from experience.

Jonny

 

Hey Tommy nice write up. I just got a NEO that i wanted to put in my 98SC400. I believe the diagram you have is for a 98-00 Celsior, And seems as though it works for the 98-00 GS400's. Is it the same wiring diagram i should use on my car?

THX again for the write up.

 

Hey so let me get this straight guys. This SAFC is to pretty much tune your engines air/fuel ratio or something? This can be used if you have just an intake and exhaust or something? If someone can fill me in I'd appreciate it. I have currently the borla exhaust and want to get an intake on my GS400. Ill probably use the "search" button and feel like an idiot later but oh well.