I was driving the other day and my check engine light came on. I read the codes with a scanner from advance auto parts and it gave me a p0264 code. I cleaerd the code and added some power service to clean the injectors. (this crappy scanner does not show the p0611 code for some reason)

My truck starts fine, it runs great, no power loss, no smoke...

So yesterday I bought a special bluetooth code reader/performance monitor. I read the codes and it was showing a p0611 and the circuit low codes in yellow but the CEL was not on.

Well last night got pretty cold and I decided to check the voltage of my batteries. Now these are diehard platinum 930 CCA batteries that are less than a year old. I was only getting 11.1 Volts at both of them.

I started my truck (in the cold) and it ran rough for a few seconds and then ran fine. I drove it for a while after it warmed up and the CEL came on again.

This time it showed the injector circuit low code in red for all 8 injectors plus the p0611 code in grey.


While the truck is running I get 13.5 or so volts. The truck runs great, like it did when I bought it. It does not skip, or blow any smoke at all. It started rough for a few seconds but isnt that normal for being 20 degrees?

My question is, could this be a battery issue even though voltage is only low when the truck is off or is this definitely the FICM? Also, could I have bad injectors even though the truck runs great? I appriciate your help!

 

Do you have a way to check the FICM voltage? It should be around 48 volts and no lower than 45.

 

You need to load test your batteries...you've probably got a bad one. 11.1 float voltage is far too low.

Other than that, it's not unusual to show a bunch of injector codes when the FICM has gone South. The P0611 code seals the deal...your FICM is bad.

 

also are you getting the battery voltage directly from the batteries or the obd port? The 13.5 sounds fine to me. There are smart phone apps now that have gauges that monitor stuff like ficm and battery voltage and everything else you should be monitoring. I for sure would not be driving it until you figure out the codes but my guess is the ficm is starting to go south

 

X2 what Steve said,

 

Yeah that's what I used, The Torque smartphone app. The 11.1 was at the batteries, however when I check the gauge for voltage at the ECM it shows 11.0 when the truck is off.

 

Should I bother checking for output voltage or should I just send the FICM out for repair? I'm sure if there were something wrong with the injectors too the truck wouldn't run so darn good.

 

Torque App can read the FICM main power voltage.

Josh

 

I see where I can read voltage at CM and voltage at OBD port. The voltage that I read was voltage at CM. I'm more interested in the voltage that the FICM is putting out

 

I had both my batteries tested at advance auto and sears. Both of them tested over 1300 CCA. Should I still replace them? They are rated at 930 CCA...

 

Seperately or together? With a low float voltage and an as new 930 cca I do not how a battery would produce 1300+

My digital battery tester uses the CCA to determine the resistance of the cells and then compares that to the load when placed on them.

Josh

 

They were both tested separately. They are DieHard Platinum batteries which are usually underrated to begin with. The first tested 1330 cranking amps and the second tested 1350 cranking amps. I asked them why float voltage would be 11.1 and neither advance or sears could tell me. Ill leave them out of the truck over night and test float voltage tomorrow morning to see what I get.

 

They have Higher CCA when testing Warm

The CCA rating is at 0*f IIRC 0r 32*f

to me looks like a Charging system issue has Killed the FICM

Hydro test each battery cell that might give you an answer to low voltage

maybe a bad ground or dirty connection or parasitic Battery Drain may also cause Low voltage

 

Ok, that would explain the ratings as the batteries were tested at room temp. As far as the batteries go, they are the DieHard Platinum so they aren't wet cell, I believe they are AGM.

 

Oh I see

I keep forgeting about that newer stuff