IsaacMT

I'm new here but I've had my 2005 Cayenne S for a year now. 84k miles and runs great. One morning CS wouldn't start...I jumped and went to work. My local mechanic who specializes in VW, BMW and Porsche. Anyway, he said battery was bad and installed a new one. I was told CS uses same battery as Toureg.

All was fine for a few days. Day 4 maybe, time to go to work...dead battery. Jumped and went to work. Called mechanic he was baffled and told me to drop by. They ran a test...I saw the printout, said change battery. He said no way could be bad battery...NO WAY! Not even a possibility in his mind that the battery would be bad. He blamed the alternator, "must be a bad diode..." He wanted to order a new alternator...not cheap. I wanted to explore further first.

I took CS in to a local battery place where they could run a draw test. I wanted to be sure was alternator. Well apparently there was a 2amp draw. By pulling fuses they were supposedly able to reduce to .7amp draw..although now the problem seems to be worse. They were baffled and told me to take to Porsche. Nearest Porsche dealership is a 5 hour drive. They disconnected power to the alternator during their tests and amp draw or drain, whatever, didn't change. This would lead me to believe there is not a bad diode draining my battery.

WTF happened here?? All was fine and then BAM...dead battery and apparently no solution for this new draw issue. I've been dealing w/ this problem for a few weeks. At first the battery would last 3 days or so if fully charged. Now a fully charged battery won't last through the night.

Does this sound like a bad battery? Was the mechanic wrong in installing a Toureg battery? If not, what could be causing this huge draw that is really killing my love affair, well maybe not love but like affair w/ my CS. I have not heard of this sort of thing being an issue. If it's not a bad or wrong battery, what could be staying on when car is off. There must be something that is not shutting off as it should. I do not have any aftermarket equipment installed. Its just your basic run of the mill CS w/ Navigation.

Any input would be greatly appreciated. Sorry for the long post first post.

deilenberger

Fuse isolation is about the only way to track this sort of thing down.. and you need an ammeter in the battery line while you're doing it. One thing people sometimes forget - is to shut off all the interior lights when doing the test (with the number of lights the P!G has - it could easily account for a 2A drain.

Once you find the fuse causing the excessive drain - you can then start looking at what's on the fuse that could cause this. 0.7A draw is still excessive if the car is in the sleep mode (dunno about Porsche - but BMW has a mode where all the modules stay awake for 15 minutes after shutdown so they can chat with each other over the CAN-Bus... you can only take current draw readings after 16 minutes - and without opening/closing doors etc - which can wake up the CAN-Bus.) I believe Porsche may have the same sort of mode since DuraMetric mentions doing something to keep the bus awake..

elycayenne06

My I left for 7 day vacation, after I opened Cayenne 06 S with the remote. It wouldn’t start. Key wouldn’t come out from the ignition. Interior light was dim, so I figured it’s time for battery change. Booster jumped it right up and even did restart after some shopping on my way to Porsche. Porsche dealer informed me that there are 3 versions available depending on power requirement. Obviously I need the most expensive one, only for $366.40 – or 389.67 after local tax. And if I like it installed it would be additional $380.
Why? Well, they claim that they check if it has “draw back”.
I figured since alternator is charging ok, 6 years is enough. I will take my chances; I will try installing it myself. I will let you know if I saved $380.

turbo23dog

Here's a link to a DIY of how to change the battery in a VW Touareg. Its said to be same for Cayenne. Also know you need a special tool to r&r the battery called a 10mm triple square wrench wihich is available at Napa Auto Parts (# SER 2305 for $6) or Snap-On, Oriely’s and Pep Boys carry them.

http://web.me.com/airtahoe/Touareg/Battery.html

elycayenne06

Success! I followed the instructions in the Operations Manual exactly. It helped that I got a XZN TRIPLE-SQUARE 8 PIECE SOCKET SET a while back. I removed 2 crews that hold a driver seat, there was some rust on the screws (the manual wants you to install new screws, I don’t see a point, and just used some oil).
As usual, the manual said nothing about 2 plastic “cops” that are behind the seat, and not allowing the seat to flip, covering the rails on which the seat slides back and forth on. You have to yank them pretty hard to remove them. . Also, had to play with them to snap them back on the rails. Other then that, I had and error on the display, saying something about air suspension being locked and inoperative, and I noticed the car was in, seem like a 1 inch higher then “normal”. I manually adjusted the setting to lower and then back to normal, which took that error off.
Now that I’m done, I’m wondering what is that other battery for, the one in the trunk?
Over all it was painless experience. $380 saved in 40 min.

ltc

The manual recommends using new fasteners for safety and liability concerns.

Re-using old screws probably means you didn't apply thread lock and for the possibility of stress cracks/fractures during removal.

Very common practice throughout the vehicle (suspension, drivetrain, etc), not just the seats.

CarreraCup03

Just had similar situation. My car was at the dealer getting the coolant tubes replaced. I get the car back ...use it for 1/2 hour or so .. then park it for the night. Next morning .. no power... totally dead. I hook up to charger, and get a little life, but wont start. I call AAA to have it flat bedded back to Porsche dealer. The tow truck guy and I chatted, and decided to try a power pack ... the car started right up. I let it run for 1 hour. He said the dealer let it run low while they where working on it. I called the dealer, and they said they would change the battery, but would charge me for the battery, which they just wrecked, and for labor.I had an Interstate battery in there that was 6 months old. I called the Interstate dealer where I got it, and they said come down .. we will give you another one under warranty. I drove down, and the guy insisted on helping me put it in. It took us about an hour .. but I have a new battery that seems to work fine now. So might have been a bad battery.

seankrider

Do you really have the second battery, in back? Did you see the wire running through the tunnel, when you replaced the one under the driver's seat?

Raybonj

Here is an easier way you only have to remover two bolts the ones under the two cover in front of the seat. You do not have to remove the hole set. I just did it on my 2004 Cayenne took about 10 mins. to get at the battery.

http://www.6speedonline.com/forums/c...guide-diy.html

If this link does not work here is how. Move the set forward, remover plastic covers at rear of set at the floor. Move set back as far as it will go, then remover the two covers on the floor in the front of the set, remover the two bolts #10/12 point. Move back of set forward and then lift the hole set backwards and up from the front, now move the set forward with the switch and it will tilt all the way into the back set. and then you have access to the battery box. Then do the reverse to put it back together.

Raybonj