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Has anyone ever seen this warning message, "Service Battery Charging System"? We had it come on Friday night. Saturday morning when I drove it to the dealer the message wasn't there. The dealer tested the battery & alt and said everything checks out fine.

Is this a false alarm, or something the service tech might've missed?
 

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I got the same error a week or two ago. The window of my car broke :angryfire: and it sat in the garage for 3 or 4 days. Guy came to replace the window and turned the power on so he could raise and lower the window arm. 10 or so minutes into it an something like "Battery Saver Mode Initiated" was displayed on the dash. We started up the engine to charge the battery and got the error "Service Battery Charging System". Ran for 10 minutes, turned it off. Started it again, same error. Battery was showing ~14 volts, which meant it was being charged. Took it for a short drive. Turned it off and back on, still same error. Called to make an appointment, and then the next morning the error was gone.

I suspect I got the error because even though it was charging, the battery was still low. Who knows though, it hasn't come back since then.

I realize this doesn't help you in figuring your problem out, but at least your aren't alone!
 

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The Acadia Lucas Electronics possession is spreading :confused:, just hope you don't get any roof leaks, then the "spirits" will take your computer completely away :comfort:
 

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I've had my Acadia for a year, but only drove it 3,700 miles as I also have two other cars. Every since I've had it the generator gage has acted funny, most of the time showing the battery was being charged. I drove it for four hours one time at highway speeds before the gage dropped to horizontal. About a month ago on Sunday the "Service Charging System" warning came on. I had OnStar run a diagnostic and they said the charging system was failing and I should get to a dealer as soon as possible to avoid a road failure. I took the vehicle to the dealer the next day and left it. They could find nothing wrong. I drove the car on a trip of about 120 miles and had no warning. Then I drove it on a Saturday for about four hours with no warning. I stopped and ate lunch and then drove about 30 miles home and just before I arrived home the warning came on. I parked the car at home and every hour turned on the key and the warning was still there for almost three hours. Then the warning disappeared. The next day, Sunday, I drove the car to see if it would happen again. It did after about an hour. It came on and stayed on until about three hours after I parked the car at home. When it happened I called OnStar again and had them run a dianostic and they gave me the same advise as before. I asked for the fault code and they told me it was a PO621 fault code. I looked it up on the internet and found out it was a failure in the generator L-terminal circuit which is the control circuit for the generator. The next day I took the car to the dealer and he has had it all this week. They were unable to drive the car long enough to create the fault, but were able to create the fault by disconnecting the wiring harness between the generator and Engine Control Module. Buy this means they believe it is either a bad generator, bad wiring harness, or bad ECM. They are replacing the Generator and the wiring harness and I have another failure, they will replace the ECM. For sure, it's a problem that occurs after the engine heats up and could be heat related. I expect this action by the dealer to solve the problem.
 
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