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AEM FIC Misfire problem

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Hi all,

I'm just reaching out to see if anyone here is familiar with the AEM FIC and can assist we a problem I am having.

I have installed an AEM FIC piggyback computer on a Suzuki Swift 2013. It has a M16A engine and I have also fitted a HKS turbo kit. The AEM harness intercepts the injector and CAS signals from the factory ECU and also taps into the MAF and O2 sensor signals. Harness was connected as per AEM instruction manual which is quite detailed.

Since installing the AEM I'm getting a misfire which more is noticeable on boost and above 2000 RPM. It occurs whenever I enter a value in the fuel map (no matter how small) problem is not present when values are set to zero. The fuel table on the AEM FIC is a percentage by which the injector pulse width is extended, setting values to zero means the FIC does not change the factory fuel settings.

Any ideas?

It's been a while since I've helped support questions about the FIC piggyback. Copy/paste info from a very old email below:

Try to change the FIC’s slave firmware... some cars will have a hesitation that feels like a soft fuel cut (the car can rev through it though), often related to the FIC’s injector strategy which is part of the slave firmware. The two common slave firmwares are z104.hex and z110.hex, some cars (Scion TC) run well with z104 but not with z110, and other cars (Hyundai Tiburons, some Mazdas) run well with z110 but not with z104.

Z104 will keep the injector phasing about the same as stock but won’t handle multiple injection pulses well (some cars are doing a long pulse followed by a second short pulse, or adding in a few short batch pulses for accel fuel).

Z110 will handle multiple injection pulses better but it will change the injector phasing, especially at high duty cycle.

Hope that helps,


Hey Scott.

Thanks for the help.

I reflashed the slave firmware to version z110 and problem went away. :-)

Would either of you have a copy of the z104.hex file. I have an FIC and need it to run my scion. I have not been able to find it anywhere. I would appreciate it if you could send it to me. Thanks


If you still looking for z104 file. let me know.

I have one.

Hi Guys

I also have a Suzuki Swift(2014) with M16A Engine, I have added an HKS GT Supercharger but I would like to get a standalone ECU. This is a daily driver and I need everything to work. Does anyone have any suggestions? From what I have been reading lately, I like the Maxxecu but I am not sure it will work. On their website it doesn't show any support for the Suzuki M16A trigger;https://maxxecu.com/webhelp/trigger_system.html.

On further reading, I think I may have found away around the trigger issue; https://maxxecu.com/webhelp/solutions_and_faq-capture_trigger_signals.html, but I would still like to know if anyone is using a standalone on the M16A, what standalone they are using and how it is working.

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