FICM supply voltage + injector circuit high codes

[TheReelMuhcoy]

I did a quick search on the FICM voltage low code and did not turn up much of anything. This code has been lingering a few weeks now, but yesterday and today I've been getting random rough idling. Yesterday I looked and saw P0271 cylinder 4 circuit high.
Is there any correlation between the two?

I hope the injector circuit is just a bad solenoid chafed wire or something simple, but the FICM supply voltage is what's confusing me.

 

[05wh250]

Do you know what the voltage is?

 

[Mdub707]

I'm assuming it's a P1378?

That means the FICM detected logic power low, less than 7 volts. Have you had the batteries tested at all?

 

[TheReelMuhcoy]

FICM voltage is at a steady 48v. Battery voltage while driving or idle is 13.4-13.8. Engine off 12.2v steady. The batteries are about a year and a half old.

 

[Mdub707]

Could very well be a defective coil on the injector. What is FICM LWPRW voltage? That's likely the one that caused the fault. Could have an open or a short somewhere.