Car gave me the "Charge System Failure" in the DIC a few days ago. DIC is showing that it is charging at bettwen 12.7 and 13.5 volts. Battery was checked and is fine.

Is there another test I can do before I should change to the Alt. and confirm that it is bad?

Thanks,
Rick

 

I have gotten that message too. Other than the message, do you notice any other problem? Dim lights, etc? Have you stalled the car letting the clutch out perhaps?

I had the message because I was stalling the car with the new clutch (not used to it) and the message would appear. I am now used to the clutch and the message has never come back.......

 

No other problems except the volts seem abit lower than they should be.

What is everyone showing Volts wish on the DIC?

 

I think mine is around 13.8 - 14.1................

 

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

 

Not sure about the C5 because of all the monitoring the PCM does, but usually you can start the car, then pull the positive battery cable off. If the car dies you got no alternator making juice. It should make more than enough power to keep the car running without battery.

 

You do not want to do this with C5....this could be very costly... offering 1980's thinking to a car with 7 computer processors, is not in anyones best interest..

 

I just sent you a PM reagarding this.

The information you sighted was VERY detailed, however you kinda lost me. So for simplistic sakes...does it look like my Alt. is gone?

Once again it's showing 12.4 ~ 13.3 volts when running. It has never thrown this message in my display before and the battery it fine.

Where should I be Volts wise when car is running?...13.5...14.0??

 

What is the volts while at idle, and in drive? Mine went out, and how I figured that was my volts was running lower, and my lights would dim every 5 sec.

 

Nothing goes dim??? Volts stay bettween 12.4 and 13.3 at idle and at drive...in fact if I rev the motor the volts do not change at all??

 

Rick, I just went down and checked mine and at idle it is 14.0 and it goes to 14.1 when I rev it under load.

 

Autozones and Advance Auto stores can hook up and do an alternator test as well as a battery test.

I don't know how trustworthy they are, because they want to sell you a new part. But maybe the sight of your car, and you, would intimidate them into truthfulness.

You get the "Charge System Fault" whenever your battery is discharging while the motor is running. Did yours say "Fault" or "Failure"?

You can trigger this like the man said, if you're creeping along with a partially-engaged clutch, or stalling the engine.

My car runs at 13.7-14.1 volts when the engine is turning, and 11.9-12.1 when it's parked and shut down.

 

GM alternators suck!!! Have had to replace the alternator in almost all of them. Put the DIC on the volts with the car running. Turn on all your accessories (a/c, radio, lights and hold the brake, wipers) and watch it. Turn them all off and see if it will charge back. Every time it went out on me I got "crazy" things happening like ABS lights and the sort. The 3.1s GM used to make were hard on alternators, but I even had one go out in the tahoe! The tahoe was the only vehicle that had a voltmeter and I could see it go down with brakes applied and not come back up.