??? are you serious or just pulling my chain?

 

I just read the complete thread. My problem was something like yours but let me ask you two questions.

The battery you bought, what brand was it?
Do you have NGKs or other on your car?

Rod

 

The problem started with the original AC Delco battery which I still have but not in the car at this instant. Its now got a Sam's Club battery in it. As for the plugs, yes, I just put in some new NGK Laser Cut plugs right before this started, but frankly, I can't imagine that its possible for those to have anything to do with the charging system.

 

Yup theres your problem the massage comes on to service charging system due to the plugs. How else could I have guessed about your plugs.

In my case the plugs were causing problems. The car ran smooth BUT when I got the "Service Charging System" message I took it in to the dealer. Check this, the mechanic installed the tech II and I was getting all kind of codes from no contact with radio unit to I know what you did last summer... you get the point

As for the voltage I have two things to say about that.

1. I installed a brand new battery because my mine was shot. I bought an Optima redtop and noticed the voltage.. I thought new battery and still problems =alternator but when I put a new AC delco in that took care of that.

2. A good tech told me to not worry about the voltage. If it starts and drives, radio and AC works then screw it.


It might sound stupid but like murphy said, "if its stupid and it works then its not stupid"

 

Hmmm....I've got a $100 code reader, so not great, but it works. No codes are present, but certainly its not remotely close to a Tech2. I was under the car a few minutes ago and found the positive cables on the solenoid were not tight. They weren't lose but they were not as tight as they should have been. With the CAT sitting about 2 inches away, my thoughts are pondering the heat is causing things to expand and loosen up but it could be the other way around, depending on the metal type of the lug, which appears to be alluminum and the contact on the solenoid is copper. Someone with more metalurgical knowledge than I can advise us better.
Anyway, its tight now. The negative cable to the engine block was tight. I'll have to drive it again to see what happens but this sure looks suspect too my limited knowledge. I do very much appreciate your thoughts SgtRod and I'm now considering putting in 41-985's again, in case this doesn't work.

 

No problem Fly guy

I didnt want to get rid of my plugs either since I had just got them but did. I've calculated $230 on spark plug nonsense(2 sets)

Im having an issue with my active handling that I suspect may be due to what you are talking about in your last comm.

Next to the CAT.. solenoid?? I had a vette specialist tell me over the phone that anything loose there would create problems.

I have limited knowledge as well

 

I edited that post of mine to change from "not" to "now".. sorry about the mispell. Yep, the cat is like 2 inches from the solenoid. I know on the C-5's, the main interconnect for power is also at the solenoid and causes problems too. I've used the Sam's batteries before on the '99 that I gave away to my son with no problems. Your presented issue with the plugs has me thinking and if this issue continues, I will change those NGK's out for 41-985's and see what happens. Will let you know.

 

Your car is an 07 so you proably didnt NEED the plugs.. that means that if you have the old ones that you could do the test at no cost.

I have headers on, so that might have something to do with my confusion of why those cables were by the cats. My cats were moved due to the headers. when you say solenoid, is that the starter? Do those cables run from the battery to the starter?

If so I will have somewhere to trace them from.

Thanks!!
Rod

 

. . .

 

Yes, the is the power feed from the battery to the rest of the car is on the starter solenoid itself. I'm at 60K miles on the car and noticed accelleration in 6th gear, isn't what it was before so even though the 41-985's are 100K, I elected to replace them with the NGK's. Performance picked up immediately.

 

2005 C6,,, Just had the same problem,, Had the battery check and it was going bad... Replaced it and have not seen any Service Charging System messages since and that was about a month ago (Over 100 degree 16 of the last 17 days, AC on all the time).. Check the battery....

 

That was the first thing I did, replaced it.

 

Well, yesterday in 108 degree heat, I saw some lower voltages when starting it up but it did Ok otherwise. Today, not even that hot yet this morning, I ran it a quick trip for lunch. In a matter of 10 minutes, I got 3 Charge System Fault messages, yet each time, the analog and digital voltage was up between 13 and 14. Touched the gas up from idle each time, the message went away. So, other than putting the spark plugs back that SgtRod suggested which I'll try tomorrow morning when its cooled off again, if that doesn't do it, it'll have to go to the dealer.

 

Dgrant3830,

All charging systems on cars should be putting out between 13.8 - 14.2 volts under load. That means with ALL accessories and lights on. The poster who had the mechanic tell him that as long as the radio and A/C work, the charging system is in order is a mechanic I wouldn't use. He obviously doesn't know how automobile charging systems work. It is critical that the charging system on any car maintains a charge on the battery. If the charging levels start to fall lower then 13.8, then your batteries stored energy may be used to compensate. Over time, without fixing the charging problem, your battery runs down enough to throw out the code.

I think you are on the right path by checking all the grounds and power connections. The mere fact that the problem is intermittent tells me that it could be a connection vibrating loose, or heat causing the problem. Electricity takes the path of least resistance. Loose/corroded connections or excessive heat could be the culprit. One other possibility could be that the rebuilt alternator is faulty. One thing to know about these alternators is that they are actually a combination of an alternator/regulator. When you have the up/down charging that you are experiencing, it may be the regulator portion of the alternator. I would have the alternator checked out as well. Rebuilders see hundreds if not thousands of these over the course of a year and one may slip through the Q/A before it's sent out. I hope this helps. Good luck!

 

Or maybe its the fact GM electronics are becoming to be like the Dodge problem.

I bought my 07 in 07. Completely bone stock (including the plugs) I got this message constantly. Took it to the dealer, first they replaced the new battery with another AC crapo battery. Less then a week later it comes on again. This time they replaced the alternator and all wires between the charging system. Two weeks later I am sitting at a light and I go from 13.8v to mid 11s (on a braaand new charging setup).

After all that crap I put in a high output alternator, msd 8.5 wires, NGK v-sparks, and a inline fuse for my audio that has a built in volt meter. At idle the inside dash volt meter would show 11-12v...I go look at the audio volt meter and heh its showing 14.4-14.5v continuous.

Since then I stopped paying attention to the stupid inside gauge and just keep driving.

 

Well this morning, I'm going down there and replacing the plugs with AC Delco's again on SgtRod's suggestion that they may have induced noice into the system. I know its way out there, but if it happened to him, that's good enough for me to try. If it doesn't work, then tomorrow morning, its going to the dealer. Reading the repair manuals yesterday, it shows that through fuse #2, Horn/Alt Sense, the ECM looks at the frequency of the output voltage to determine if the alternator is rotating. If so, the ECM sends a command to the regulator to turn on. It also looks at the demand from the systems and the frequency to determine how much charge is needed. If the voltage gets too low, the ECM will send commands to the BCM to start lowering power draw starting with the heat elements and next, the blowers. From that and the rest of what I read, it seems too me that when the engine compartment is very hot, this command either isn't being sent or its not reaching the regulator. New battery, brand new alternator(not rebuilt now), tightened all connections and so on...still has the problem. If its not these plugs, then its the ECM or a cable.

 

I'm sorry you've been on such a mision with this issue.

I'm sure that your gonna wait a couple of days before you come to your conclusion due to trauma.

If the spark plug story seems weird, you should hear what else happened.

I have a funny story about airbag sensors too.

My airbag lights kept comming on at high rev/speed. I had them replaced and replaced. Guess what it was...... My VR cai was not secured tight enough at the front bar, causing the vibration close to the sensor to trigger the light!!!

Goes to show that when mods are involved the manual can sometimes be useless(I can laugh now).


Good luck brother!!!
Rod

 

I like your logic and I think you are on the correct course. My money is now on a cable or ECM. Let us know how it turns out. Good luck!

 

It is the spark plugs. The same thing is happening to me right now and have been happening for the past year.

The Service Charging System message come on every now and then but always at idle. It would stay on for about 3 seconds then go away.

Took the car to the dealer and they knew right away it was the spark plugs. Told me that it doesn't hurt the car, just go ahead and enjoy the car. I went down to a colder spark plug range.

 

I think you could be right, mine never did it until I did a H/C package, and guess what came with that? New spark plugs.

The problem reared its head again when I changed valve covers and went to the coil relocation kit, which required new plug wires. I've been trying to figure out how that could be related...

Since I had my tuner turn it off, still no problems and no more ding-ding-ding flash...