Apexi afc install instructions

S-AFC Installation


Entry-level fuel computer designed to modify the air flow meter signal

can be used instead of the GCC for finer control of your VPC.

Easy to read VFD display, unparalleled list of functions

The second generation SUPER AFC follows the highly successful SUPER AFC in an
upgraded package. The SUPER AFC is a vehicle specific fuel computer that
modifies the air flow meter signal/ pressure sensor signal and allows the user
to either richen or lean the fuel mixture. Adjustment ranges from +/- 50%. The
Super AFC boasts an 8-point adjustable fuel curve with 500 RPM increment
setting points. The Super AFC also allows the user to adjust fuel enrichment
according to either LO/HI throttle positions. The AFC also cures the erratic
idle problems associated with open atmosphere blow off valves on hot-wire air
flow meter equipped vehicles. MONITOR MODE shows analog meter faces, Y graph
display, Numerical display, Peak Hold, Replay Mode, 1 point/10 point and ghost
map tracing. All correction factors are also displayed in percentages.


Here is
what you will need:

S-AFC wiring harness and head

10mm socket

Wire crimpers

Butt connectors
and the supplied connectors


get started!

1.Remove the negative
battery cable.
2.Remove the wiring harness
from the ECU. 
3.Refer to the ECU diagram.


  1. Splice
    the Green
    Wire (RPM) into 58.
  2. Splice
    the Gray
    Wire (Throttle) into 43.
  3. Cut
    wire 66 in half, leave yourself enough room to connect a wire to ECU harness.
  4. Connect
    the Yellow
    wire to the 66 wire connected TO the ECU harness.
  5. Connect
    the White
    wire to the 66 wire heading AWAY from the ECU harness.
  6. Splice
    the Brown wire (ground 1) into 69,
    close to the ecu.
  7. Splice
    the Black wire (ground 2) into 69 at least 1cm away from the Brown
  8. Splice
    the Red wire (12V+) in to ECU wire 31.
  9. Pink
    and Orange
    wires are not used.

Now you have all of the wiring done, double check all of your
reconnect the wiring harness
to your ECU.  Make sure all of
those wires are still tight. Plug the harness into the S-AFC. 
Reconnect your battery cable. Turn the ignition to the ON position. 
The AFC should boot up and display A’PEXi, if screen did not light
stop disconnect the battery and find out what went wrong. 
Most likely it is power or ground problem (or a loose ecu harness.)


If the
unit Powers On
, follow these steps:

start off by
Resetting the AFC.
Many have often complained that their AFC does not show full
regardless if
it is brand new. Go under
[etc.] and
press NEXT~>. Confirm “YES” when prompted “Init.
All?” and
press NEXT again, Now turn the ignition OFF and then back ON, and the unit
should now be reset and ready.

enter the following basic settings: 

-Go to [main]
~>[setting] ~> [3. TH-Point] ~>
[Lo-94, Hi-95]

-Go to [main] ~>[etc.]
~> [1. Sensor Type] ~> [1.
Hot-Wire]  ~>  [in-12, Out-12] ~>  [in-1, Out-1]

-Go to [main] ~>[etc.]
~> [2. Car Select] ~> [Cyl:6, Thr: UP]

-Go to [main] ~>[etc.]
~> [3. Graph scale] ~> [Ne = 7000rpm]

[Ne-POINT = 3500, 4000,
4500, 5000, 5500, 6000, 6500, 7000]

[Dec. -Air = NOT USED, unless you
want to use it to compensate for venting your BOV to atmosphere]

Do not modify the low
throttle settings.  While at low throttle (in closed loop mode) the ecu
will counteract any changes made and over time your long term fuel map will be
modified.  I recommend modifying your high
throttle fuel curve on the dyno with an air/fuel ratio meter & egt gauge
installed.  For maximum power, one
probably wants to run an air to fuel ratio of between 11:1 (rich) and 12.5:1
(lean)  Do
yourself a favor and pay a professional to tune it.  If you lean your
engine out, things can melt.

Blue wire
mod info:

This allows you to read Oxygen
Sensor Voltage on the AFC display. On the wiring harness for the AFC the blue wire
is not normally used. The blue wire is meant for
the second Mass Air Flow Meter on a Nissan  300ZX. You will connect this wire
to the O2 sensor wire right at the ECU.
To read the O2 sensor voltage, scroll down to and select the “etc.”
menu. Select the “Sensor Check”. Of the three readings, O2 voltage
will be the middle one (#2).


If you are installing the VPC with
the AFC, then install the AFC on the output wire of VPC



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