"Charge system fault"
I just returned from a 1700 mile trip to Bloomington Gold on Sunday. Had the car out last night and oarked it for a while. When I started it up it had been raining and i got the message. I switched the display to the battery volts and it seemed to be jumpping up and down, but only by a few tenths of a point. I'm thinking that the alternator may be going up. What do you guys think?

 

I got the "charge system fault" message as well. Anyone know what it means?

 

usually that the alternator isn't putting out enough voltage - should be reading in the high 13 to low 14V range when running...

 

Either your battery is gettin "To Much or "To Little" charge.
Is DTC P0562 or P0563 stored in the PCM?

1) DTC P0562 System Voltage Low
2) DTC P0563 System Voltage High

 

I get the Charge system fault every now and then, usually within a few seconds after I start the engine. My suspicion is that occasionally the alternator doesn't put out enough current for a pre-programmed time period, and therefore triggers the computer to display the fault on the DIC. I'm not sure what the specs on this are, but it only happens about every 6 months or so, so I chalk it up to a computer glitch.

If the voltage is jumping erratically, then my suspicion is the alternator is just about ready to go. Since you said it was raining, another possibility is that you might have got some moisture in the alternator. The problem may go away after things dry out.

I'd keep an eye on the battery volts on the DIC for a while, to see what the voltage is doing. If it looks like your between 13.5 and 14V as ptdrummer54 indicated, you should be OK. If the voltage keeps jumping around, I'd have the alternator checked out.

Don

 

my DIC flashed that message one day, i hit reset and never saw it again until a week later when my AGM battery shorted internally and died.

 

Here is how the alt/gen works....
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 get this message too, I've been looking at the DIC while it was on the volt gauge and SAW the voltage change by around 2 volts one time while cruising.. Went from around 14 to 12 and back to 14, I suspect a ground wire or alternator messing up

 

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. Evil-Twin
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If I understand this correctly, if the alternator doesn't get up to operational speed shortly after the start cycle, but the PCM is expecting that the circuit is at ignition voltage, could it be that the drive belt may be slipping on the alternator for a few seconds longer than the PCM is expecting?

Don

 

yes, that is possible.. I would check the condition of the drive belt, and the pulley system, including an inspection of the grooves in the tensioner pulley, idler pulley, and Harmonic balancer pulley. Any slippage could send the wrong signal.