What electrical problems are associated with the C6 and what years are most effected.

 

My battery won't last more than about a week before it's dead.

 

I have that same issue on my 2005. The dealer swapped out the battery three times already and told me my charging system is fine. Which I find hard to believe. Any ideas out there. Another electrical problem I have is my fuel gauge needle will all of a sudden go to zero and stay there for a couple of minutes, then return to a normal reading.

 

battery for the most part. I think the drain is do to the NAV system.

 

My 08 does not have navigation.

 

I can help with the second issue. You've been burning high sulphur fuel and it has contaminated the fuel cards. Quit buying that nasty high sulphur fuel, and run a bottle of Techron through with the next tank.

With respect to the battery going dead, if you haven't already, have your dealer do the reflash of the BCM that Chevy came up with to stop the self-discharge. Be sure to remember to always park in reverse, and disconnect any 3rd party electronics in the car. Unplug the underhood light too.

 

For folks who actually want to find and fix the battery drain issues with your cars. Get out your multimeter, set it to the amps scale, and connect it in series with the negative lead of the battery. Wait 20 minutes for the car to put itself to sleep. Now start pulling fuses until the current drain drops to below 20 mA (that's the normal "keep alive" value for the BCM and RCDLM). The fuse you pulled which caused the current to drop is the one for the circuit which has the problem. Replace the defective component or repair the wiring fault, whichever is the cause of the drain.

 

Nice to hear a reasonable, helpful answer. This constant replacing of batteries that we see here in the forum shows a basic misunderstanding of the electrical system and electricity in general. If the car is drawing more current than it should when it is sitting in the garage, then it doesn't matter what kind of battery you have. Red, yellow, purple top, whatever! Unless the battery is out of a piece of giant construction equipment, it will be drained by this excessive draw of current in a fairly short time. The difference between a cheap battery and a red top etc might be 25%, which means that instead of it taking 7 days to kill the battery, it will take 9......no significant difference.Simple to check the current drain on the battery with a meter and then track down the source as stated above. Not that everyone here should be able to do that, but certainly any auto tech should.
If the cause of the excessive draw is not found, then no better battery will help the ultimate problem. Because of this thread, I measured my current draw and found that after a few minutes of sitting, the car draws current that runs between 11 and 17 ma, constantly changing, as they probably have the receiver cycling, but averaging about 14ma. At this rate, the battery would be able to go for weeks and still be able to start the car.

 

That is very good troubleshooting advice...

 

Make sure the battery terminals are clean and tight, that is a GOOD connection. It is easy for the current to jump a poor connection on starting but very difficult to trickel back on charging with a poor connection.

 

Battery Problems: Install Pritority Start and never worry about it again

 

Onstar goes into a sleep mode after the ignition is off. Could there be a defect with Onstar which causes a drain in the batter?

 

Had the same problem with the battery right after I got my '06. Found the radar detector (a V1) was causing noise on the 12V line. I rewired it to a source so it would shut off when the car did. Had to use a o-scope, amp meter to find it. The BCM in the car draws a lot of current if it is awake, like a couple of amps, but only about 20 mA if it is asleep. The noise kept the BCM awake and drained the battery very quickly. BTW, when toubleshooting a low amp draw, be careful putting an amp meter in series with the battery, as some inexpensive amp meters do not fuse their high currect side of the inputs, only the low current side. I also found cell phone chargers, the cheap ones, will also induce noise on the 12V line causing the BCM to stay awake.

 

Not me. I found out the Priority Start was the culprit that was draining my oem battery. I threw that piece of priority junk out along with my oem battery. I then got myself a Deep Discharge Optima Yellow Top. At least it can drop dead a 100 times and still be recharged. Try that with the oem or whatever else battery.

Thus, since I got rid of the Priority Start, I have never had to worry about my battery again!

 

How? If it removes the battery from the circuit at 11.7v what could it do to drain the battery? I've had one on my car for over 3years and it's saved me quite a few times. I have an 05 and people just don't hear you when you say put it in reverse to turn it off, even the dealer I'm also running a Yellow top

 

It may go to sleep, but it isn't dead. Onstar has to be one of the systems drawing some power, because Onstar can be woke up to transmit the current info for its monthly analysis reports.

 

If the car is going to sit a while why not put a battery tender on it?

By the way, what is priority start?

 

I am not the first person to say it, cuz I didnt believe it either, But it does draw power to operate and is the main contributor to bringing it down to 11.7 or lower! That's OK for a Yellow Top which can be recharged many times with no effect on the battery, but not good for a non deep discharge battery. I have a Battery Minder Plus (tender) I use twice a year for a few weeks on the Yellow, to desulphate the battery and keep it in top shape.


PriorityStart monitors battery voltage and automatically disconnects any undesired drain on your battery as the voltage reduces, when the engine is not running. It essentially is a battery disconnect switch. The disconnect threshold is factory set at 11.7 Volts.

Problem is, the Priority Start is an added undesired drain on your battery!

Battery tender is OK but it should also be a desulphating one too.

 

How did you find it? I have been looking all over the car for a way to do this. I have tried the old trusty amp meter but could never find it. any chance you have some pictures?

Thanks for the help.

 

You know I hear all these horror stories and I think a great big kudos goes to all those guys offering details for diagnosing DBS, but my '05 with the auto tranny has never had one electrical gremlin and is still on its original battery. To top that off, some bozo (me) forgot to plug the tender back in when I was in the barn over Christmas time. Found that on Monday and had visions of horror. Amazing thing was, though, it started right up anyway with no jump or boost prior. So, how do we explain a well-mannered C6 that never has battery problems?
--
Jay

PS. Yes, it's an A4 since my bad back doesn't handle clutches well.