Has anyone else had this? "Charge System Fault" shows up intermittently on the DIC when I start the car - 2003 coupe with about 18,000. The dealer couldn't find anything wrong. I've had no work done on the electrical system (I think some were getting the message from changing the alternator). It happens approximately one out of every 5 times I start the car. Original battery. Any suggestions? BTW, I didn't get any codes when I reviewed the codes on the DIC. Thanks.

 

See this sticky thread

http://forums.corvetteforum.com/show...84&forum_id=49

I get this message often

 

I read somewhere on the forum that this sometimes happens in really hot/humid weather and you have the A/C cranked when you turn the car off. When you start the car, the A/C starts and you get his message. It's happened to me twice, but no issues so far. I'm sure others more knowledgable than me will chime in.

 

This is normal...The charge system (alternator) has not caught up yet
right after a start. There's a significant voltage drop during startup
and the system is reporting it as a "Charge System Fault" because
it senses that instantaneous low voltage condition.

As soon as the alternator gets a few turns in, it gets back to normal.

...George

 

AS I have posted many times:

The L-terminal circuit from the generator is a discrete circuit (a discrete circuit has no splices and only one source and destination) into the PCM. The PCM applies ignition voltage to the generator L-terminal circuit. A small amount of current flows from this circuit through the generator windings to ground to create a magnetic field which starts the generator process. When the generator is at operating speed and producing voltage, a solid state switch for the L-terminal circuit in the generator opens and the PCM detects that the initial startup current flow has stopped.

The PCM expects to detect low voltage on the L-terminal circuit prior to the generator rotating at operating speed and conversely expects the circuit to be at ignition voltage potential when the generator is operational. When the PCM detects a fault (circuit shorted to ground, or circuit shorted to voltage), the Driver Information Center will display Charging System Fault.

The generator has an input to the PCM called the F Terminal to indicate the percentage of total capacity that the generator is producing. This signal is detected by the PCM as a duty cycle from the generator and displayed on the scan tool as a percentage. The PCM can monitor the generators output under all conditions to determine if it is functioning normally.

When there is low demand from the electrical system on the generator, a low duty cycle percentage will be displayed. As more accessory load is placed on the generator, the duty cycle output detected by the PCM will approach 100 percent. A normally functioning generating system will never reach 100 percent as indicated on the scan tool.

The L and F terminals are the red and grey

Understanding this will help, also the alt/gen is in constant communication with the PCM, having the right alternator/gen -PCM link is important..... This charging system is Not your average charging system....

I hope this helps.
Bill aka ( ET )

 

The bottom line here is that GM is not effectively addressing this problem. They either need to re-issue the original 110 amp alternator or do a software correction to allow for the use of this "replacement" alternator.

 

My inside source is telling me that the fix will be a re flash of the PCM with proper algorithms to communicate with the New Alternator Offering. Since the Original French Made Valeos are no longer available.

 

Is this something currently available to the dealerships through their TechLine?

 

Bill (ET), so are you saying this is normal???? Sorry I'm not an engineer, so I don't know if I really understood what you were saying! I have actually communicated with Bob at Fichtner re: the issue because I had seen a related thread. As I mentioned above, I have not changed my alternator. I read his thread as meaning the only problems were replacement alternators, not original equipment. He (Bob) actually said I should take it to the dealer to have it checked if I haven't had to replace the alternator. Was there a change in the oem equipment so that after a certain date GM changed to the 140 amp alternator without updating the PCM? It sounds like what I'm hearing is that it is a software problem and I don't really need to worry about it......correct? Thanks for the help.

 

Thanks for the explainnation Evil-Twin, but I really do not understand what it all means
So are you saying there are 2 types of Charge System fault?
Oh great another re-flash .

GM needs to do something about this issue.


I had this message with the OEM alternator & Battery as well as with and the replacement alternator and Red Top Battery .

2 different dealers have seen my Vette for this message. The new alternator was supposed to be the fix. Of course, that did not work. Then I read a new battery will fix it. Of course, that did not work either. So at this point since nothing has fixed it, I am at the point of ignoring it (until a new thread pops up).

This is just my experience with this message. I have been getting it from 3500 (I bought this Vette used) to 37,000 miles and so far it has not caused a problem. It is just more of an annoyance .

 

That's reassuring.....I suppose all in all, if that's the worst thing I have to worry about in a day, I'll take it. I agree.....it hasn't caused me any problem of which I'm aware.

 

Any other comment?

 

That's comforting to know. I thought I had really messed up by riding in the humid Gulf Coast air with the top down and the AC blowing. Somehow I know that's not the right thing to do, but it was a beautiful afternoon drive along the beach (with the heat index at 110).