Hello the dealer disconnected my battery and installed a new alternator on warranty. (1999 Vert)

Since then...I have received the "charge system fault" message on the DIC dozens and dozens of times. In town, light on/ lights off and on highway at 65mph lights on/ lights off.

Additionally, my passive lock/ unlock pass Key has quit working. I changed the battery in both fobs to no avail. The buttons on the fob work, the not the passive element of the system.

Looking through the manual at these issues, it indicates a low battery could be the cause. I purchased my Optima redtop during January 2001. The volt gage shows the system charging and I noticed no dropping of volts when the charge fault message is displayed.

Help!

 

search for forum member Bill Curlee...our electrical guru..sure he will jump in here

 

Did you take it back to the dealer? What kind of voltage readings are you getting? You can also check to see if one of the pins on the alternator molex bent. Or maybe the molex is not plugged in all the way. I would take it back to the dealer.

 

Follow-up. I am taking it in this week. My vette is an A4.

As for reading...and I am doing this from memory. Engine not running key on, foot on brake 12 volts (on the DIC)

Engine running at 65 mph lights on I think around 13.6 to loq 14s.

Engine idling lights on at stop light (foot on brake - stereo - heater - defogger on ) 12.6 to low 13s.

I know this is an important question so I have to wite a log to answer 100% correctly.

If my memory is corect...is there a clue there?

 

I just go my 02 back from the dealer (let's not discuss why) and I am experiencing some strange things since. It started at the dealer's place OK, then I stopped to get gas. When I got in, it played music in the front speakers only. I shut it down and restarted. It seemed OK. I drove to work (about 50 Miles) with Headlights (raining), windshield wipers, and stereo on. Everything ran OK. Got in it that evening to go home, and got clicking noises and no start. Had it jump started and ran it over to a service center. They tested everything and said it was all OK, but I'm still seeing fluctuations on the gauge from 13v to 14.4v. Is this normal?

It seems to run fine, but I notice that the digital readout for the A/C is a little dim when I first start up. All other gauges and readouts seem fine. When I turn up the gauge brightness to full, it goes up, but it takes a few minutes for it to look normal.

 

There is a sticky note at the top of the Z06 section that is related to the installation of a new alternator and the "charge system fault" error message.

 

There are (apparently) at least 3 different "models" of alternators for the C5.. The symptoms you describe are similar to those experienced by folks who installed the "wrong" one..

PM "Evil Twin" (or attempt to do a search).. He has first-hand knowledge of what I'm talking about, along w/ the part numbers as well. If that doesn't pan out to be the issue, then at least you've eliminated it as a possibility.

 

Check the sticker on the alternator... The one they installed is probably 140 amp. Your 99 NEEDS a 110 amp. It is apparently difficult to get a 110 amp alternator. My parts manager can't find any 110 amps. I myself need one for a customer as well.
If anyone out there knows where to find the 110 amp alternator, Please let me know

 

the Valeo 110 amp alternator made in france is the only one that communicates with a pre2001 pcm properly..the 145 Valeo made in Mexico doesnt work.. it actually does work, but the pcm reads a fault because the PCM is not reading the values designed into the pre 2001 pcm..it is reading an over charged condition.


The PCM monitors the alternator through the red and grey wires If you eliminate them,you will have a problem...Read the description below:
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

I know for a fact that GM is not addressing this isue and their pat response is that they have had no issues with this... But I know for a fact that a few dozen people have had this same problem here on the forum and several forum vendor GM dealers have tried to intervene, but gm has blown them off as well... I tried to get involved with Gm on this issue but was blown off..
I was able to get the proper 110 French made valeo for my car about six months ago..
My suggestion now is to find a 110 french made valeo at a C5 salvage yard.. GM PT # 10246634
If it has a belt clutch on it, it wont work..