Check the most obvious things first using a multimeter... Battery and alternator, also check terminal connections. One other thing to check is the master fuse located on the passenger firewall as those are known to go bad.
Goodluck.

 

I don't know where the master fuse is. I don't have a fuse box on the firewall passenger side that I know off. I have a internal fuse box on the drivers side and a big fusebox on the drivers side under the hood. Am I looking in the wrong place?

 

I don't know where the master fuse is. I don't have a fuse box on the firewall passenger side that I know off. I have a internal fuse box on the drivers side and a big fusebox on the drivers side under the hood. Am I looking in the wrong place?

This is the fuse I'm referring to,

 

I'd first make sure your battery terminals are shiny-clean on the contacting faces.
Next remove your alternator and have your it tested.
Next would be chasing a ground loop- do you have any aftermarket electric accessories installed? Alarm? Remote start? Stereo stuff?

 

Thanks,

I found it. Would have never found it without your help. Off to the auto parts store

Thanks Again

 

The mega fuse likely isn't the problem. If replacing it does fix the problem, it is probably due to the fact that its connections were bad and you cleaned the connections by removing and replacing it. If the fuse itself was bad, almost nothing would be working on your truck. It is like the main fuse for the truck that controls almost everything. That is why it is such a big fuse.

My first though would be the alternator or battery/grounding connections as stated earlier in a post.

 

Thats why I suggested that you do the obvious things first..since you have a new battery check the alternator.. After that check connections...

 

I agree talon, but what the hell, a mega fuse is only about $5, I think. Then maybe the alternator and connections will be next.

 

The computer will adjust voltage from the regulator as accessories are turned on and off.
I would turn all lights on, stereo (don't need to blast it), and AC on full cold. If you are not charging between 13.6 and 14.6VDC then have the alternator checked. If it is charging above 15VDC, replace the alternator.
It could be a fuse to. So check fuses.

 

Thanks for all of the Info. I changed the Mega Fuse and had the alternator tested and everything checked out. Cleaned the battery terminals and made sure they were tight. Everything checked out and it is still doing it. I will start checking the fuses and look for bad connections next. Wish me luck and Thanks again

 

I have completed all of the suggestions given and still have the issue. I had the alternator checked and it was ok. I installed a new ground strap as well. It does not seem to do it as often now. Maybe once every 3 days. I replaced the Crank Position Sensor and took it to the dealer to have it relearned. They are going to do a complete system scan as well and see if anything else might be causing the code to appear.

 

I still cannot find the problem:

Here is everything I have done.

1. Replaced Battery
2. Alternator checked---OK
3. Replaced Mega Fuse
4. Cleaned Battery Terminals
5. Installed new ground strap
6. Checked all fuses
7. Took to Dealership. Replaced the crank position sensor and hooked up to the diagnostic machine and found no more errors.
8. Drove home and the light came on again.

Don't know where to look next.

 

Was a solution ever found for this issue? I have an 09 Silverado 1500 5.3L V8 that has the exact same issue. The error doesn't appear to happen all the time and seems to only really happen under load after the electric fans for the radiator kick in. I have a new battery, a new alternator and plan on checking the mega fuse and grounds as well as other fuses. However, knowing my luck with this lemon that won't fix the issue. I just had a DOD done on the truck and have a diablotune installed that deleted the AFM as I had a lifter fail that destroyed the original cam in the truck.

Any help is much appreciated!

Thanks,
-wrath39

 

Hey man. I know I'm late.. but did you ever fix that "Service battery charging system"????? Please I hope there is a chance you see this and replay. Please text me at xxx-xxx-xxxx.

(Moderator note: phone number removed. Is is never a good idea to post an email or phone number in a public online forum.)

 

I’m late too. But my battery light/service charging system came on while I was driving to work @6AM. It was off when I got off @2PM. Had my battery/charging system tested at autozone. Came back as a bad voltage regulator. Can’t really change it without basically replacing the alternator since I’m not that much of a DIY person.
Hope this helps.

 

Another site suggested checking the battery current sensor.

 

It is possible to have a new battery that’s bad