Just throwing this out there to see if anybody else has had this problem. 2005 STS V8 RWD with 11500. Been driving car about 13 months in Arizona. However car is garaged most of the time. Drove it 3 times yesterday with no problem but when I went to the car this evening it was so dead I needed the key to get in. No accessory power. The battery was entirely drained or had an open circuit. . Roadside Service came out and replaced the battery and all is well with normal charging. Seems kind of soon for Arizona Battery rot, considering the mileage and fact it is in garage when not being driven. My only other concern is that several days ago I had the ECM update done. Hope the new program is not causing a battery drain.

I went through 2 in less than 4000 miles on my 05 STS V8 1SF. When the second battery died the message "Charging system not functiong properly, Service Charging System" in the DIC. Dealer nor Cadillac tech support had no clue what the problem was, and to this day still have no idea.

I had to have mine towed to the dealer after 8K miles they said the battery was defective, I had not drove it for a week when the battery malfunctioned.

My dealer has replaced the dead battery in my 2005 STS (took delivery in March 2005) twice. Says the car with all its electronics drains batteries (???). Use the car almost every day so it does not sit around.

I had to have mine towed to the dealer after 8K miles .

From all the answers, it would seem GM is going for the bargain and buying cheap batteries. Especially bad for these cars because when the battery shorts out or has an open circuit the gear shift relay won't work so that one can shift to neutral and push the car out of the way. Also, if you are outside the car the keybob won't open the car (hope you have your key).


By the way, strange that you had to have the car towed. If you call the Cadillac Road service 800 number they will come to your car location and replace the battery on the spot.

I let the 05 set for 9 days. Battery dead. Replaced by roadside service. Am told by dealer they have the same problem when cars are not driven. They have used solar chargers to keep things up and fresh. If you let the car sit for more than a couple of days, by a battery babysitter and use it. Many of the car's systems do not shut down when key is off.

I was having some similar issues when I first purchased my 2005.

Here are some of my post:

I have gone out to start my car (http://www.cadillacforums.com/forums/#) twice now, and have had to jumpstart it because the battery did not have enough juice to do the job. I checked to make sure that I had not left anything on and had not. Took it to the dealership, where it is right now (overnite) so as they can try to figure it out. Someone I know who has an Acura (http://www.cadillacforums.com/forums/#) with the keyless ignition as was having the same problem, another friend with a new Vette (keyless as well) had the same problem. The dealership told them that they both had not been turning the car completely off, that they were leaving it in the on position unknowingly. Has anyone else had this issue? If so what was the solution?

#2

Ok the first time I was convinced by my dealership that I was not turning the car (http://www.cadillacforums.com/forums/#) off properly. They tested it for a day and a half. Took the car home and it started fine for about two days (these two days I drove it on both.) I let it sit for 3 days, volleying between my Vette and Yukon (http://www.cadillacforums.com/forums/#). Go to hop into my brand new STS to find that "click" "click". The F-cking battery is dead again. I hook the Jumpers on it for one second, and presto, it fires up. Let it sit another 2 days and same thing happens. This time I call the dealer and they tell me to leave it alone they are on my way out for a "house call". They pick me and the car up, put me in a SRX (which I love, my wife loves, and the kids love) .

After a second time back 2 the dealer, the car stayed there this time for 4 days, while they and GM (http://www.cadillacforums.com/forums/#) conversed on what was draining my battery. Ok I finally seem 2 have gotten to the bottom of it all. The problem was the Onstar module in the trunk. It would come off and on thru the nite, causing the battery to drain down just 2 the point that the car would not have enuff juice 2 start. They ordered another Onstar unit (or took one from another STS) and installed it.



Here are some other suggestions from forum members:


The start button is a traditional rocker switch, meaning it only recognizes UP or DOWN. The two icons on the bottom of the switch are only there to illustrate that the lower portion can perform two functions. OFF if pressed while running and ACC if pressed while off.

One of two things is happening: Either you're accidentally pressing it twice and putting the car in ON mode (full accessory only happens when you hold the lower portion for 5 seconds with the car off). What happens then is the equivalent to turning the ignition to the first "click" in a car with a traditional key.

or

You're leaving a key fob in the vehicle (http://www.cadillacforums.com/forums/#) while it's parked in the garage. If you do this, the anti-theft system is constantly scanning the fob, keeping the alarm deactivated. Over time, this drains the battery. This is why your horn honks 3 times if you leave the fob in the car.


#2


I had dead battery.
Delco has recalled many. Mine was one of them. Bad cell is known issue. Your dealer will find based on VIN series.
Good luck,
-john



I have not had any problems since April of 2005, altho I only have 9K on the car. I hope that I have nothing but good luck the rest of my 41K mile journey or until the ULS is in it's second year (I hope) which ever comes first..

cmicasa: Thank you!

my battery went dead within a few ours - they found later 46 mistakes in the computer, but were unable to define which caused the problem.

patrick - germany sts v8