Ok it is finally here:
Here is my humble "how to" for the installation of A'PEXi SAFC II on X-Trail 2005 QR25DE engine (Canadian Edition):
** This write-up does not cover the initial set up configuration and tuning of the SAFC II. This should be done by a knowledgable tech.
** Also take note that once your SAFC is installed and powered you should immediately do initial set-up before starting the engine.
** Warning:
- Not for the faint at heart.
- Knowledgeable and at ease with wiring & soldering is a must.
- Not responsible for "screw ups".
I can't say it enough: Read, Re-Read, and PLEASE Read again ALL documents supplied by A'PEXi with the unit.
Find a suitable location for mounting the unit.
I located mine in the hidden double door compartment below the climate controls. (see below)
Take off some side panelling to find a suitable route for the cable.
Access the ECM location by:
- removing the "lower panel" (part 27 in picture) snaps in only
- removing the "glove box" (part 31 in picture) by removing two holding pins (part 32 in picture)
- removing the "glove box cover" (part 36 in picture) held in place by a quantity of 6 screws (part 3 in picture)
(While taking this last part be careful not to pull apart the air bag connector)
So far these steps are the same as what is needed to access the "cabin air filter" (models equipped).
You should now be able to see the ECM as per below:
WARNING: Before disconnecting any ECM harness connector: YOU MUST Disconnect the batterie negative terminal.
(unfortunately this will screw up radio settings and clock

)
Disconnect harness connectors as per pic below and carefully remove the protector covering the connectors.
Also carefully pull away some the black plastic wire covering; you should now be able to see clearly the pin connector and each wire.
Start identifying each wire color and confirm the terminal point number:
Terminal----car ECM--------------sensor------------------A'PEXi SAFC II
number----wire color---------------------------------------wire color
# 15---(wire color white)-------Knock sensor---------------color purple
# 50---(wire color white)-----Throttle position--------------color grey
# 51---(wire color orange)---Mass Air Flow sensor--------color white & color yellow
# 116--(wire color black)----------Ground------------color brown & color black
# 120--(wire color grey)-------Power Supply----------------color red
# 103--(---no wire----)--------Tach RPM-------------------color green
All SAFC wires tap onto ECM wires except for the MAF sensor;
MAF sensor wire is to be cut:
SAFC's yellow wire connects to ECM side of #51 orange wire
SAFC's white wire connects to car's MAF sensor side of orange wire
In the case of the car ECM RPM signal:
Some model years (in this case 2005) do not have a wire attached to the terminal # 103;
you therefore have to get inventive on how to insert a wire into the terminal # 103 and get a good connection. Some report heating wire end covered with solder and inserting it into the terminal socket, but I would prefer some other method; I have not figured that one out yet but as soon as I do I will write a follow up.
In the case of the SAFC ground wire: there are two wires (brown & black) that need to be connected to the same car ECM ground wire with only a small space between them (no less than 1 cm). Also note that the SAFC brown wire should be the one closer to the ECM side.
- The above wire color codes correspond to my 2005 X-trail with QR25DE Canadian Edition.
- Color codes for your particular car should be doubled check in your applicable service manual since they may not necessarily match.
Once all connections are done, soldered and secured, tidy up the harness, put back the insulation, button the harness back to the ECM and close up the area in the reverse order.
(I will be seeing my tuner/technician/chemist this coming thursday for proper tuning, and will report back on the improvements)
If you are interested in accessing my SAFC II on my page, here is the direct link:
"SAFC II"
There you go, I'm done. I hope this helps and is not too confusing...
Comments welcomed.