The Diesel Stop banner

Real World FICM voltages?

19K views 7 replies 7 participants last post by  tlottman 
#1 ·
So, '04 in sig has a fairly constant miss & lingering #7 contribution code. Before I go that route, wanted to to see what the collective thoughts are on my "Main" FICM voltage... read via TorquePRO & multiple Blutooth ODB2 adapters

Under most circumstances it's consistent 47.0V, but on occasion will dip to 46.0-46.5V... none of which are the 48.0V I've read about. FWIW, there doesn't appear to be any relation to outside/engine temps and the FICM voltage, but engine does run rough until warmed up.

Are there other voltages I should monitor to further pinpoint (potential) FICM issues?
 
#2 ·
Your ficm main power is good. I would have your batteries load tested and have the alternator output checked. Low battery voltage is the #1 killer of FICM's, especially on cold starts. You can check your FICM's logic power. It should be 12 volts KOEO and 13 to 14 volts KOER.
 
#3 ·
Yes weak batteries can kill the FICM. Run ruff to start then smooth out if older than 4 years I would change them out. I have one of these in the power port to keep an eye on the volts when setting and going down the road plus it will tell you if your alternator is working overtime to charge your batteries.
Amazon.com: INNOVA 3721 Battery and Charging System Monitor: Automotive
You know what to volts are before you start.
2 stroker
 
#4 ·
Remember the logic side of the FICM can fail even if the power board is OK.
 
#5 ·
That's where I was going @Ford06 !!
I'd read about several folks chasing intermittent "misses", running rough and power loss... that were rectified by swapping/replacing/repairing the FICM...

While I've checked the harnesses, the FICM voltages, and run several buzz tests on the injectors (via a "Nemesis"), I couldn't help but think the symptoms were eerily similar to what others had reported... even after swapping injectors :surprise:
 
#6 ·
...........

Under most circumstances it's consistent 47.0V, but on occasion will dip to 46.0-46.5V... none of which are the 48.0V I've read about. FWIW, there doesn't appear to be any relation to outside/engine temps and the FICM voltage, but engine does run rough until warmed up.

Are there other voltages I should monitor to further pinpoint (potential) FICM issues?
While that is above the often stated lower level of worry, the FICM has a problem. A good FICM will run 47.5 to 48.5 with only a rare 47.0 popping up.
 
#7 ·
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top