AEM FIC Tuning

[CTScott]

Originally Posted by Scubaru Steve

the reason im asking these questions is that im not used to tuning piggy backs, my wrx i can just hook in my laptop and open source tune my ecu, i have found no product to do it for the 1nzfe.

so now with this piggy back i get to try to tune.
i have been reading the book and i see that there is an afr-voltage table.
there is also something in there stating that you can install a resistor in the wiring so the fic can output the proper voltage to keep the stock ecu happy in closed loop. is that what clamping is called? when done to the o2 or maf?
at what cfm does the maf hit 5 volts? is it even possible with the t14?

as for open loop.... im sure its the same for all 1zfe's? when does it switch over from closed? i know wot is open...

For the 02 Sensors:
Sensor 1: 0 to 7.999V
Sensor 2: 0 to 1.275V

The MAF sensor normal operating voltage range is 0.4V to 2.2V (below 0.2 and above 4.9 will trigger a DTC).

The three conditions that I know of that cause open loop are coolant temp below 75C, WOT, and O2 Sensor below a certain temp (I don't remember what temp off the top of my head).

I have done some experimentation with forcing open loop, but have yet to find a method that doesn't eventually set a DTC. Fooling the coolant temp input seemed like it was going to work, but keeping it in that state for more than 900 seconds (15 minutes) of driving causes an "Insufficient Coolant Temperature for Closed Loop Fuel Control" to be logged.

[cdydjded]

Originally Posted by CTScott

For the 02 Sensors:
Sensor 1: 0 to 7.999V
Sensor 2: 0 to 1.275V

The MAF sensor normal operating voltage range is 0.4V to 2.2V (below 0.2 and above 4.9 will trigger a DTC).

The three conditions that I know of that cause open loop are coolant temp below 75C, WOT, and O2 Sensor below a certain temp (I don't remember what temp off the top of my head).

I have done some experimentation with forcing open loop, but have yet to find a method that doesn't eventually set a DTC. Fooling the coolant temp input seemed like it was going to work, but keeping it in that state for more than 900 seconds (15 minutes) of driving causes an "Insufficient Coolant Temperature for Closed Loop Fuel Control" to be logged.

Directly from the electrical master....

[Focus_Sh1ft]

Directly from the electrical master....

Yeps.

The way I see it is you're going to get a CEL no matter what you do when attempting to force open loop. Why not just unplug the AFR sensor and take complete control?

I think the only method that hasn't been thoroughly tested in forcing open loop was by decreasing the amperage that reaches the O2 heater. I remember I was reading it supposedly won't throw a code if it's above .8A, and usually it operates at a higher amperage during closed loop. However it's likely it would throw a code anyway if it didn't heat up within an certain amount of time.

Toyota =/= Subaru in the slightest when it comes to aftermarket ECU tuning lol.

[Scubaru Steve]

i dont mean keeping it in open loop. as for not being able to heat up the o2 sensor that will give it a shorter life span and probably throw a code.
on page 18 of the instructions its saying "fixed" mode the fic outputs a square wave that alternates between the bank high and low voltage.

maybe ill just do the open loop for now then mess with closed.

anyone know where closed ends and open starts?
also... anyone have problems with bov's? i know it runs rich for a split second, but does the ecu try to solve that?