Ficm Voltage with AE

PABowhunter · May 12, 2015

I was running some data logs with my AE tonight on my dad's 6.0 and noticed the ficm main power voltage was reading 40.5-41. The truck started and seemed to run fine.

The ficm was just rebuilt by a local shop. Am I reading the wrong value? Is there a software issue with my AE?

PABowhunter · May 12, 2015

I know it should be 48v

little luke · May 13, 2015

I'd actually test the ficm just to be on the safe side. Was that while key on, starting, or running?

PABowhunter · May 13, 2015

Truck was running. I'll test it right at the ficm. Didn't know what the proper way to test with AE was. Or if it's always better to test at the ficm itself.

Lassie · May 13, 2015

Check it key on, starting, and running with AE first. Low voltage readings with AE is usually a bad FICM. AE smoothes the signal to a degree, so if it's low with AE, it's low

PABowhunter · May 13, 2015

I know there were a few different ficm options. The main power is the one I want to watch correct?

Lassie · May 13, 2015

Yes, there is Logic and Main power. Main is the one to monitor

PABowhunter · May 13, 2015

So I checked it again with key on engine off, starting, and at idle. 40.5 on all three. Guess it's time to take it back to the shop that rebuilt it and see what's up.

How low does the voltage have to get for the truck to run rough?