Compression Ignition Addict
Join Date: Jun 2011
Location: Colorado Springs
Thanked 0 Times in 0 Posts
Mentioned: 0 Post(s)
Quoted: 0 Post(s)
Feedback Score: 0 reviews
Low battery = Low FICM Voltage?
After putting on a DIY coolant filter, I set to programming the ScanGauge 2 with the 6.0 X-gauges.
I checked the FICM voltage at KO, engine cold and was getting 48V. However, when I start the engine, the voltage drops to the 30s and eventually comes up to the 45 range. One thing that I also noticed is the voltage reading for the truck (on the scangauge) is about 12.5V when running. I have only owned the truck for a month or so, but the batteries look like they are pretty new (appear to be a matched set on Interstates).
Will low battery voltage cause low FICM voltage? or do I have both a FICM problem as well as a failing alternator?
Thanks in advance.