2002 Z06 "Charge System Fault"

[vettegirlz06]

For several months now I will get this message on starting, but my guages always show a full charge so I've been ignoring it. This morning however, my car was totally dead - the door locks functioned, but nothing else - not even a guage sweep (drove it yesterday, everything fine). Do I just need a new battery, or could something else be wrong?

Thanks!

[c4c5specialist]

HI there,
Well, first thing is first, recharge the battery or replace it.
It sounds like you had low reserve capability within your battery, so when you started it up cold, the lower voltage surplus cause the 'service charging system' message.
If it ONLY happened at first start up, its probably the battery.
Allthebest, c4c5

[vettegirlz06]

Thanks! It did just happen at start-up, and not every time.

Just pulled the battery and it actually has caps on it (OEM battery I would guess, I bought car with 12K miles on it). Maybe I should have been putting water in it all this time? I didn't think they had this type of battery anymore...

[c4c5specialist]

HI there,
the caps are ONLY VENTS>
It is not made to add water, so dont try to.
Remember, connect the negative battery cable last and torque to 11 ft lbs on both terminals.
Allthebest, c4c5

[vettegirlz06]

Originally Posted by c4c5specialist

the caps are ONLY VENTS>
It is not made to add water, so dont try to.

Too late, just dumped a bottle of Zephyrhills in it. Guess it is time for a new battery!

[BruceF]

Even if your battery was designed to have water added, you should only use distilled water as the minerals in tap and bottled water will harm the battery.

[Cruncher]

I have an '03 Z06, purchased new. Starting about a month after purchase, I would see the Charge System Fault message, mostly when the car was cold. To this day, I still get the message. Under warranty, I have had the alternator replaced, a new battery replaced, all connections checked...nothing could be found. GM does not have a fix for something that affects a whole lot of C5s. However, in all cases, the starting, driveability and/or operation of the car has not been affected.

[c4c5specialist]

Hi there,
Yes, there is ALWAYS A FIX.
Fact is, there are many problems that could cause the "charge system fault" message.
Please give us your battery test readings, how long the battery sits between the start ups when you see this message, what your parasitic power draw is, and alternator output at the time of the message.
Allthebest, c4c5