Can anyone tell me a bit about this FICM

BD Power - Product: 58-Volt FICM

 

Waste of money. There is no real gain with the 58 volt FICM. If you need a ficm, go see Ed at ficmrepair.com and just have it redone.

 

ok thanks I was just curious

 

I've heard that it will throw a code and set a CEL.

 

Some reading on Swampsdiesel.com regarding 58V FICM.

Mine's been in my truck from swamps (58v) for over 4 years. No problems.
In truck when I purchased.
Emailed them with some help last fall and even tho I wasn't original purchaser Dave guided me through emails with all the help I requested.

 

The 58 volt FICM supplies a higher voltage to the injector spool valves. It might open and close them marginally faster, but at the expense of higher current in the coils, and the open/close speed is irrelevant to performance anyway - stock is already extremely fast. The only performance advantage I've been able to figure out is having some additional power available in the spool valve to overcome mild stiction. The downside is you would normally expect the injector spool valves to fail earlier, if the mod doesn't change the output FET's in the FICM they will not last as long, the FICM will run hotter, etc. If I were going to consider a modified FICM, I would probably build a 50 volt FICM. My stock FICM runs up to 49.5 volts on the scan gauge every once in a while, if my alternator is charging at over 14 volts (like after three starts at 30 degrees in 5 minutes, bad idea and I won't do it again if I can help it).

 

This may be a bit off topic but it is in response to the latter part of your post, I have a stock 6.0 with a stock FICM and a stock alternator (with a SGII) and when I first start my truck cold the main volts drop to around 11.5 to 12.0 and the FICM volts will usually drop to around 47.0 to 47.5 during the glow plug cycle but when they shut off (or about 30 or 40 seconds) the volts climb back to around 13.8 to 14.5 and the FICM goes to 47.5 to 48.5 (bounces mostly between 47.5 to 48.0) I have not seen it go lower or higher ever. I'm wondering now, because of what you stated about the three quick starts, if a higher output alternator would have an effect on the FICM voltage ie:make it hold on a higher voltage and if so would that be an advantdage? Thanks for any input. and Happy Thanksgiving!

 

I think alternator voltage has a minimal effect on FICM voltage, if the alternator voltage is in a normal range and the FICM is in healthy condition. I say this based on my understanding of the FICM power output circuit (remembering back to electronics school oh those many years ago) and what my truck does, so it's just an somewhat informed opinion. The FICM has electronics that create a reference voltage and a switching power supply that supplies the power tied to that reference voltage. It's easy to have a few percent variance in voltage levels, and the difference between 47.5 and 48.5 volts is basically only plus/minus a half percent, or nothing in the real world. Next is how the Scangauge monitors the voltage - it just reads the output of the OBDII port, and it's information is from an analog to digital converter that feeds information to the computer. They have an accuracy and variance as well. I know that the SGII reads main power voltage a bit low, for example, on my truck because I also have an Autometer voltmeter and have checked against my bench meter.

My truck reacts about exactly the same as yours except for the FICM voltage. When the glow plugs are on, I get main power at 11.5 - 12V and FICM at 48 volt. When the engine fires I get main power at 12 - 12.3 volts and FICM at 48 - 48.5 volts. After the glow plugs go off (up to 2 minutes) I get main power at 14 volts and FICM at 48 - 49 volts. When I did my three cold starts I saw main power at 14.3 volts and FICM bounced up to 49.5 a few times, and after the batteries stopped taking a big charge voltage went back down to 14 and FICM returned to normal - 48 - 49 volts. I think your truck is normal, FICM is within normal tolerances for a good unit. If it drops to 45 volts when the glow plugs are on is when you start to look for a charging issue or a weak FICM.

My opinion, of course!