I just had a custom tune for my 2008 C6. The next day I was getting a message to Service Electrical System. I checked with the shop where I got the tune, they suggested disconnecting the battery, which I did, left it disconnected over night, but the same message the next day. Any ideas on what could be the problem?:*****

 

Did you ever figure this out? I have the same issue

 

Im going to bump this to see if there were any updates or solutions as my car has it now (along with a 1V lower voltage symptom)..

 

I had the same problem with my 2013 427 convertible that lasted 4 years because GM would or could do nothing. the owners manual says take it to the dealer which I did from day one and when they looked it up in the computer it didn't say anything.
They called GM and they were no HELP at all. when the car was 2 years old and still no resolution from GM I got the Sh*ts of it and I put on headers with a program from ECS.
The dealer kept trying to get some help from GM without any results. The dealer and me even went so far as to put a new PCM in the car to try and get HELP from GM. No dice
This year I got in touch with Doug at ECS and took my car to Carlisle and he put in a new program in it and NO more Service Electric System
Thanks Doug
Sorry for this long reply but I wanted to let you know that GM's HELP is PI$$ poor and what I had to do to get it fixed.
Call Doug at East Coast Supercharging and maybe he can help you or your tuner

 

I had a similar problem turns out my horn fuse was bad. I know it sounds silly but that's what it was. If your horn works fine then it could be your alternator.

Or maybe mine said charging system. It's been almost 2 years

 

Pretty good advise!
Mine is tuned by him aswell. I'll ask him. Thanks!

 

Did some googling on the service electrical system (there are so many forums with corvettes wow), and so many of this same common issue many left unsolved while going though same ideas!

Random FIXES that have worked for other forum members over the years;
-New alternator
-New sparkplugs
-Send ECM back to tuner (fix emissions code, or delete the DIC message).
-Repair/replace O2 sensor wire burnt from long tube headers sloppy install
-Horn Fuse
-fusable link
-MAF
-Battery
-Replace fuel vent solenoid


However the above list is a combination of two separate messages on DIC .
(http://www.lbfun.com/warehouse/tech_info/C6/);
Two messages people have are;
"SERVICE ELECTRICAL SYSTEM"
Press the RESET button to acknowledge that you have read the message and to remove it from the display. The message will reappear until this condition changes. "This message displays if an electrical problem has occurred within the Powertrain Control Module (PCM). Have your vehicle serviced by your GM dealer."

"SERVICE CHARGING SYSTEM"
"Press the RESET button to acknowledge that you have read the message and to remove it from the display. The message will reappear every 10 minutes until this condition changes. You will hear multiple chimes when this message is displayed.
If this message comes on while you are driving, you may have a problem with the electrical charging system. It could indicate that you have a loose or broken drive belt or another electrical problem. Have it checked right away by your GM dealer. Driving while this warning message is on could drain your battery.
If you must drive a short distance with the message on, be certain to turn off your accessories, such as the radio and air conditioner."

So, mine says "Service electrical system", so maybe not the alternator, not sure yet.

i think suspects could still be;
-Check O2 wiring at long tube headers, and any loose wire from install.
-sparkplugs - will swap to AC Delco.
-Tune/pcm (contacting the tuner now).

 

(also posted under Z06 category)
Thanks to some of the forum members mentioning thier O2 harness being burnt by sloppy aftermarket header installs i decided to check mine, big clue was the car sometimes would have a rough idle when warming up to temperature (when o2's come into function).
I Found 2 cut pieces of wire in my O2 sensor extension. Ordered a new one, will install next week!

 

Let us know if that helped you out. I know I just had a post about an electrical gremlin I just fixed and life makes sense again. It takes a while but eventually you can fix anything.

 

That was you right? Thanks for posting your find, it definitely helped me.
I will be surprised if this wont fix the issue.
Ordered a new harness from ARH, arrived in 2 days. Hoping within the week to get the new harness installed! stay tuned.

 

No I had another electrical issue and I was browsing through all the electrical posts just to see if I could help or you guys could help me come up with a solution. I sent you a potential problem with the horn system. Which oddly enough happen to be my problem yet again.

 

oh ok, my horn is working loud and clear...

 

Fixed the issue, then had to take the car to a shop to reset the DIC.
The problem was as i posted above with the sliced O2 wire, and because it shorted out the o2 fuse was blown too. Replaced the o2 sensor extension with a new one, problem solved for me.
Note for the readers: this issue likely only applies to having aftermarket exhaust headers.