Slight diversion from the peanut gallery - In discussion in this forum, a few years back there was a thought that the circuitry may have a low voltage protection. Any truth to that.

And to bring up old points, what do you two believe are the causes of failure?

Are you attempting to test the Converter Stand alone bench testing or as assembly with Complete FICM in your vehicle??? The digital side has all the individual injector Power FET drivers for injectors on its half. If you are testing the FICM as a assembled unit I'm not sure you can do that without being fully install in the engine with ALL its connections with associated signals so that everything powers up correctly. You also do realize there is a difference between a 4 screw and a 7 screw converter board ?? If you have a 7 screw you will need a signal generator to generate a clock signal for the converter board but the 4 screw doesn't need this.

I think there is some misunderstanding/confusion for the purpose of wiring the resistors? The resistors would be used in place of the injectors as a single static 10 ohm DC load solely on an properly wired individual stand alone convertor board (48V). NOTE that 48V is HAZARDOUS to ones health and can STOP your heart or collapse a lung resulting in DEATH!!!! Wired stand alone on bench one can test the converter board to its fullest capability way without the digital side causing any ambiguities!

I think you will be marginal with your power supply being limited at only 30A if you will be attempting to verify the converters FULL potential (without looking up my original post from years ago I don't remember the exact number, I believe you will need min 40A ideally 50A). You can use one battery but make sure in any case that you have a fuse inline (one can draw well over 1000A from a charged battery, which burns things up in a fraction of a second and much quicker then human response time !!

Note you should NOT be doing this unless you are familiar with your trucks wiring and the involved circuitry, preferably with electronic knowledge of the involved devices !!
Appears good starting point to review the past 18 yrs history on the blog for the 6.0L FICM past problems, lot of issues addressed there???

One should not open nor operate the FICM in open conditions without fully understanding of the potential risks for personal injury in doing so! These are only suggestions and are not all inclusive and only intended as general guidance for someone experienced in the technologies employed and one does so at there own responsibility and risk of peril.

With all due respect... you are correct it does!! Its call a dead battery :-X22

Can one be more specific ?

Personally I've only looked at a hand full of these units un-touched by anyone else besides myself. None of the failures I've seen were due to the digital half of the FICM failure. Even other third party vendors had similar issues. Though the OEM unit was stamped as made in "Mexico" and third party appeared to have implemented the same components and circuit board with revision # marked up by 1 however it was stamped as made in "China".

Some failures were caused by the infamous lack of solder on joints, which I opine was poor quality control during manufacturing which was further aggravated due to FICM being mounted to a vibration table with temperature stressors added due to the operating environment (AKA engine block mounting to PS 6.0L diesel).

I'm also of the opinion that it was a marginal design where some of the components had marginal break down voltage ratings compared with their normal operating voltage/temperature specs i.e. power MOSFETS and electrolytic caps. Some failures were multiple component failures where the under rated power MOSFET would take out the pre-driver FET and the Power MOSFET source resistor acting kind of like a fuse in the circuit opening up and allow the three other converter circuits to limp along at a lower voltage.

I would attribute some of the failures due to the uniqueness of the circuit board design employing several layers with many vias interconnecting layers under power devises for both thermal conduction and higher current capabilities hindering and not properly controlling the soldering processes.

I would also contribute some of the issues due to FICM mounting and poor routing and stress relieving of the FICM harness.

Just my opinion on a limited statistical sampling.

Yes, a no-voltage situation certainly is a protective condition.

One person on the forum said he would not be surprised if the Siemens FICM did not have a limiting circuit that would interrupt if voltage dropped below a specific voltage, 8.0v as an example, protecting the boards. I never heard anyone make that statement prior. That of course is the major belief for FICM power board failure, low voltage.

In your review of the two versions of the FICMs, 4 and 7 screw, does it appear one would be more robust, a broad category.

You also have to keep in mind that when these units were being created. They were also in the early days of lead free solder.
Early lead free solder was not the best thing.

A low voltage cutoff... kind of a novel point and I'm not sure the 6.0L would even crank at 8.0V? If we assume the alternator normally runs at 14 volts, as its voltage drops from that point the current to the converter increases so as to maintain the 48V output. Around battery at 10.8V the current drawn by the converter will be around 40amps. Anything lower the converter output voltage rolls off from 48V. It seems most people are more concerned about maintaining the full 48V. However I did confirm the 48V starts to droop at a battery voltage at10.8V limit which was the purpose of the test (this was the 4 screw version). It would be reasonable to expect that the power converter would quit at some low voltage, not sure whether there was any intended protection purpose based on all the problem issues of the design??

I've only worked on one 7 screw, only because the owner wanted to make sure the problematic joints had plenty solder on them. There was nothing observable at a causal glance to make one appear more robust then the other. His board I touched up using silver solder which is inherently stronger and has a higher melting point.

It seemed to work pretty well as long as one used the correct flux and plenty of solder to truly fill the joint. Seemed early on that the wave machines had a
problem in fully filling the joints whether cleaning, flux, flow rate or heat at issue not sure. Maybe just a matter of fine tuning the machines for the new solder
and flow rate?

Yes, I do think it was more a bit of tuning of the process and maybe the solder and/or flux.
Keep in mind that the overhead display was prone to cold joints, taking it out of service.

Thanks, theonlypheniox.

The comment from the other person was so long ago that I may have confused the power converter dropping out with designed protection.

My concern for some time was the FICMs were more likely to be hurt during the starting event when the voltage drops into the 11.2v range and below, lower with diminished batteries as people tend to be lackadaisical about starting voltage drop. Not uncommon for some people to say the voltage is 10.0 to 10.5 in some cases during the winter. I believe I've read in the Ford literature the 8.0v FICM lack of function but cobwebs at this age. If so, should we be more concerned about the batteries than the alternator since even the meager 110a alternator will maintain approximately 11.5v during glow plug operation? Not saying the 90 seconds of ~12.0v may not play a part.

You said, "as its voltage drops from that point, the current to the converter increases to maintain the 48V output," which also got my attention. I need to observe this more, but a few years back, I observed, I believe, 85amps spike on the FICM negative wire at key-on. I pulled my engine out before I played more to record the current spike at engine start if there was another.

I've got a weird situation. '05 with a remaned FICM from Ford. Injectors don't buzz when ignition is turned on. FICM voltages are good, 48v mpwr. No codes come up and truck will not start. Will not buzz injectors with scan tool and does not set any codes! Any ideas?

Historical back ground with my F350 (the road less traveled):
Please note that my experiences may be slightly different from the average user posting here for a couple reasons. I purchased vehicle new, I am the only person that
performed ALL maintenance and repairs (only exception being tire service) on my vehicle which is a '05 F350 6.0L PS, SB, dually with the factory opt emergency high
output dual alternator (about 240A combined) with 190K miles on the clock. The only non factor options I've added are the Corsa exhaust and Banks high rise turbo
piping and my personal modifications to the FICM. Contributing factors to my experience was living in northern ILL where typical winter temps can reach -20F and the
town I lived in one year held ILL state record low of real temp -36F.

First winter '05: I determined factory oil was not appropriate for the northern ILL winters and switched to Rotella T6, change intervals every 5-6K miles. Further I have
run this oil ever since along with various fuel additives. 5 years later: The OEM batteries were getting tired, so they were replaced with two Sear Platinum AGM
(my understanding were made by NorthStar in that day). These batteries have performed flawlessly to this date. Exception in July '22 when the main alt went out
and the second alt was noticed to have a noisy bearing, both replaced. Batteries still continue to operate flawlessly even when they drained nearly dead where
the engine would not crank. (this episode may have shortened battery life)? over interim years: had other non battery nor alt nor FICM issues but typical F350
maintenance issues. Forward to 2012: I get a call from the wife that the truck engine is not running "properly"? She was right I got the truck home scratching my
head what was going on? Directly going to this blog to be clued into the FICM problems which seem to hit a high point when updated for the injector preheat
programming. The rest became history pulling the FICM and setting up bench testing for myself. Analyzing the FICM I found one power MOSFET had shorted
taking out the MOS pre-driver for it and the power FET source resistor acted as a fuse which open up with a visual burn mark. The failure appeared very intuitive
that something was amiss! Upon further investigation of electrolytic caps and power FET max voltage specs the design was marginal when taking consideration for
degradation due to high under hood temperatures with mounting directly on the engine without even considering any transients on the battery supply! It should be noted
that with lesser battery's then the NorthStar AGM the failure may have occurred earlier. The more inductive loads there are in a vehicle i.e. starter, alternator, winches,
high power lights, high power Amps, etc the more likely transients will be generated. As Clint Eastwood said "Do you feel lucky pilgrim"! As batteries age there internal
resistance goes up making it less likely they can suppress high transients. Then there is the obvious issue of poor soldering on many of the converter boards which is
just a ticking timer.

As for power increase/decrease from the set point (48V); Power in is = to Power out - any conversion losses. So one consumes more power then one gets out.

In general discussion there should be a turn-on spike to charge all the FICM on board capacitors but depending on whether you are using a clamp on current probe and
whether its the single line feeding just the FICM, I'm not sure I would expect that much of a spike but also what was the duration of the spike? Also depending on the
engine temp one has the injector pre-heat cycling to contend with.?

Unit is defective or assuming you got the complete FICM (logic and power converter) direct from Ford service department, and you installed yourself?? If that is the
case your FICM needs to be program to your vehicle and without the service tool you can not do it. One can get away from this programming step if they replace
only just the power converter half of the FICM assuming that was the only original defect?

Clamp-on ammeter off the negative FICM wire reading peak, no way of knowing duration. 2003 Pilot Injection programing before induction heating. The reading location was the 10ga negative from the FICM to the inner fender ground point, G101. Cold start, Key-on; Wait to Start.



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I don't remember at the time if that was the 7 screw or 4 screw FICM installed.