AEM F/IC writeup
- Thread starter Ricktalife
- Start date
bikingpro5
Member
- :
- 03 Protege5
Pm'd LMK what you think as i have one installed as well and still learning to use it properly. Just want to make sure for anyone else whose going to install it that we have the all the information we can.
CR3 Motorsports
Member
JDWK Ill be using the o2 wired up to the Analog A. What else do i need to do to run that?
Just intercept it like you did with the injector signals. The AEM will just pass it as is until you mess with the Analog A map.
I had the best results by putting it in offset mode and just taking all cells that are in boost and putting them at a -.4V offset.
Narrowbands oscillate from around .1 to .9 volts. By offsetting it by -.4V, the highest it will reach is .5V at it's absolute richest. So the PCM will only pull fuel very briefly.
The tricky part is getting either your MAF or Fuel maps to match this so that fuel trims go to zero. It is imperative they are zero.
It is kind of a difficult concept to grasp, but we are tricking the PCM into thinking the O2 is leaner than it is. But if we let it add the fuel it will keep increasing the trims until they are maxed out and those trims will carry into the open loop operation and you'll run ridiculously rich and hit ignition cut because even a stock car will break the 100% duty cycle limit.
So we have to tell the AEM to add the fuel so that the mixture is enriched and the O2 reads as close to stoich as possible. This is supposed to be around 5V, but found it to be closer to .45V. So for example: If we want to run a 12:1 AFR under boost, we have to offset the O2 signal to trick the PCM into adding fuel since it wants to be at 14.7. For me, this was around .4V. Then you go into the fuel maps and for those same cells, add fuel until the trims zero out so the PCM is not adding any extra fuel. Both long and short term trims must be brought down to zero. It's best to reset the PCM (unplug it) and zero out the long term trims so you start with a blank slate. I found I needed about a 13% positive adjustment across the board to get them to zero. But this will be different for every car.
Here is a screenshot of my O2 map.
I had the best results by putting it in offset mode and just taking all cells that are in boost and putting them at a -.4V offset.
Narrowbands oscillate from around .1 to .9 volts. By offsetting it by -.4V, the highest it will reach is .5V at it's absolute richest. So the PCM will only pull fuel very briefly.
The tricky part is getting either your MAF or Fuel maps to match this so that fuel trims go to zero. It is imperative they are zero.
It is kind of a difficult concept to grasp, but we are tricking the PCM into thinking the O2 is leaner than it is. But if we let it add the fuel it will keep increasing the trims until they are maxed out and those trims will carry into the open loop operation and you'll run ridiculously rich and hit ignition cut because even a stock car will break the 100% duty cycle limit.
So we have to tell the AEM to add the fuel so that the mixture is enriched and the O2 reads as close to stoich as possible. This is supposed to be around 5V, but found it to be closer to .45V. So for example: If we want to run a 12:1 AFR under boost, we have to offset the O2 signal to trick the PCM into adding fuel since it wants to be at 14.7. For me, this was around .4V. Then you go into the fuel maps and for those same cells, add fuel until the trims zero out so the PCM is not adding any extra fuel. Both long and short term trims must be brought down to zero. It's best to reset the PCM (unplug it) and zero out the long term trims so you start with a blank slate. I found I needed about a 13% positive adjustment across the board to get them to zero. But this will be different for every car.
Here is a screenshot of my O2 map.
CR3 Motorsports
Member
Sick!
- :
- 03.5 YLW MSP
Just added Protege - AEM F/IC Install to the how-to quick links!
js_protege_03dx
Member
- :
- 2003 mazda protege dx
So i have an aem fic installed by a shop and had them tune it as well. It has been hell trying to get them to fix the issues with my car since ive had them install it, so ive decided to look into it my self. I bought the cable to hook it up to my laptop and downloaded the software. Now how can i read or see all of the information? I see on the instructions that you need to open up a new calibration file and start from there, but how do i just open up my current tune? i currently have a cel. forgot the code but it is maf voltage too low. replaced the maf with a known good maf and still the same. The reference wire from the maf is reading voltage but when i hooked up a generic scan tool up to my obd port, it showed the ecu reading no voltage. I just want to double check and see if the aem is reading voltage and possibly go from there. also the car drives and runs fine when warmed up. Cold starts are the problem. anywhere below 2k rpm, the car will studder and cut off. im assuming that is due to the maf issue. If anyone can help, please let me know!
The MAF signal has to be divided correctly, and then adjusted within the software because the MAF signal is not linear.
When you connect your laptop to the FIC and load the software, you'll click connect. If the current open tune does not match the one on the FIC itself, it will ask you which way you want the tune to go. FIC to the software, or software to the FIC.
Since you can actually get the car to run, I would choose FIC to the software.
Your problem makes perfect sense. If the divider uses a resistance value that is too low it will stumble and throw a CEL. But since the relationship is not linear there is no perfect resistance value. I used a potentiometer to vary the resistance until I found a spot where the car idled well with zero fuel trims so that cold starts didn't suck.
Then I used the MAF table to modify the MAF as RPM and load increased.
If you don't want to break out the soldering iron and change the resistance, you'll need to modify the MAF table to get the car to idle properly.
You need two things for the FIC to be possible. A OBDII scanner that can view live data, and a wideband O2. Without those, getting the car running right is all but hopeless.
When you connect your laptop to the FIC and load the software, you'll click connect. If the current open tune does not match the one on the FIC itself, it will ask you which way you want the tune to go. FIC to the software, or software to the FIC.
Since you can actually get the car to run, I would choose FIC to the software.
Your problem makes perfect sense. If the divider uses a resistance value that is too low it will stumble and throw a CEL. But since the relationship is not linear there is no perfect resistance value. I used a potentiometer to vary the resistance until I found a spot where the car idled well with zero fuel trims so that cold starts didn't suck.
Then I used the MAF table to modify the MAF as RPM and load increased.
If you don't want to break out the soldering iron and change the resistance, you'll need to modify the MAF table to get the car to idle properly.
You need two things for the FIC to be possible. A OBDII scanner that can view live data, and a wideband O2. Without those, getting the car running right is all but hopeless.
js_protege_03dx
Member
- :
- 2003 mazda protege dx
^^ sorry for the late response, i am trying to connect the fic to my laptop right now so i can at least post up a screen shot, but the connect button will not light up allowing me to click on it. i dont want to lose the current tune so i dont want to try anything like i usually do. do you know how i can open my current tune? like do i need to open a calibration file? also i see a button that says upload cal only. what would happen if i click on that? Thanks for your input also. Really want to get my issue resolved.
js_protege_03dx
Member
- :
- 2003 mazda protege dx
i was reading up in the manual online, do i have to open up a base calibration first? i dont see that file anywhere, is it available for download?
yes, there should be a base.fi6 file or something like that in the AEM directory when you install it.
Here was my last tune I believe. I no longer have the FIC, so I can't be of too much help.
https://docs.google.com/open?id=0B1eecaR7erA6Tnl2Z2xaZHBLYnM
Here was my last tune I believe. I no longer have the FIC, so I can't be of too much help.
https://docs.google.com/open?id=0B1eecaR7erA6Tnl2Z2xaZHBLYnM
js_protege_03dx
Member
- :
- 2003 mazda protege dx
it says i need to upgrade the software. i dont know if the aem thats installed on my car was tuned on the upgraded. does it matter? again im sorry for all the questions, just dont want to lose my tune.
thanks!
thanks!
js_protege_03dx
Member
- :
- 2003 mazda protege dx
awesome, i will try it tomorrow and post up a screenshot! appreciate your help!!
I install the AEM FIC using the AEM FIC Wiring diagram for MSP.
The car star but it shut down Code p0355, In the first page says it could be wires not connected how the supposed to be or I'm missing the resistor!
I disconnect the MAF WIRE and put it back like OEM, cars start and do not shutdown now!!!
I used the 1,100 resistor and cars starts but dies. Where I should put the resistor?
In the cable that goes from the FIC to the MAF? right? or ECU TO FIC?
I would like to have the MAF connected to the AEM FIC, so my tuner could have more options to play with it.
The car star but it shut down Code p0355, In the first page says it could be wires not connected how the supposed to be or I'm missing the resistor!
I disconnect the MAF WIRE and put it back like OEM, cars start and do not shutdown now!!!
I used the 1,100 resistor and cars starts but dies. Where I should put the resistor?
In the cable that goes from the FIC to the MAF? right? or ECU TO FIC?
I would like to have the MAF connected to the AEM FIC, so my tuner could have more options to play with it.
Don't intercept the maf
