You're in the DTS forum but you need a voltage tester attach it to the battery with the car off. It should show a voltage drain. Now pull each fuse one at a time until the drain stops. Then find what is connected on that fuse and go from there.

 

Battery still drains even after replacing passenger seat sensor, new batteries and three weeks in there different repair shops. Help

 

Welcome to the forums!

 

It's back in the shop right now. When the 2008 Cadillac CTS gets back I will follow up with you. I'm hoping I can post the fix for this mysterious battery drain. Thanks for responding. If the issue isn't resolved maybe you can give suggestions for fix.

Marty

 

Seattle? Sunroof? These cars are notorious for the sunroof drains backing up and spilling water inside, causing all kinds of electrical problems.

 

If you want to find out what circuit is causing the battery drain by use of a good multi meter that allows supporting about 10 amps for current loads

As I picture below
Take off the positive battery lead cable and connect like a #14 Gage wire from it to the + of battery post
Connect both leads of meter to each side of that wire.
Set meter to Amps
Allow good 15 minutes for all controllers to go into sleep mode.
Cut the wire and turn meter on in Amps mode.
Write down what the AMP reading is

One by One pull a fuse and see if the Amp reading goes down
If not pull next fuse, repeat until you find the circuit that is putting the load on battery
May have to do this for each fuse panel the vehicle has

 

If you want to find out what circuit is causing the battery drain by use of a good multi meter that allows supporting about 10 amps for current loads

As I picture below
Take off the positive battery lead cable and connect like a #14 Gage wire from it to the + of battery post
Connect both leads of meter to each side of that wire.
Set meter to Amps
Allow good 15 minutes for all controllers to go into sleep mode.
Cut the wire and turn meter on in Amps mode.
Write down what the AMP reading is

One by One pull a fuse and see if the Amp reading goes down
If not pull next fuse, repeat until you find the circuit that is putting the load on battery
May have to do this for each fuse panel the vehicle has

View attachment 574998

Thanks for your post. I'll share it with highline electric who has the Cadillac now. They guarantee they'll find the problem.

Marty

 

It has been my experience that going to different technicians will lengthen the process to find the problem if they can ever find it at all. Stay with one repair shop so they can isolate the problem.
When you go to different shop they have to start testing everything all over again.

 

Your Welcome Marty

Keep in mind with today's vehicles with several controllers that they are connected to a internal network (Starbus, or CAN or GMLAN)

When they are awake then there is a lot of current draw and can stay awake for like 15 minutes before going back to
sleep mode which then the current load drops

So when doing this type of testing do not be opening doors, etc to keep them in sleep mode
If in doing the testing the current load goes up then something awoke controllers and must wait then till
they go back to sleep mode and current load drops to then continue pulling a fuse at a time.

 

Thanks, I have finally found the issue for my 3-4 month battery drain. If you have followed my CTS 2008 Cadillac. After three different Cadillac certified mechanical shops and one specialized electrical shop. We found the problem in the passenger seat sensor. We ordered the part and after the gm strike we had a local Chevrolet certified mechanic shop make the repair. The problem still persisted with the battery drain. We then took it to another Cadillac dealership and had them review the issue. They found the installation of the passenger side sensor was incomplete. they completed the installation and now the car runs fine and the battery issue is solved. My wife's 2008 CTS Cadillac is worth 5k. We ended up paying an additional 5k after all was said and done. I hope this might help some poor sole who might go through the same nightmare. I would like to thank all of your support and help finding the cause.

 

Thanks for the update, Marty.
Can you clarify...Passenger seat sensor... for the airbag?

 

Yes, I believe airbag as well as other function. I will get part number when my wife brings car home.

 

Dunno if I have a heater but not needed here. Do like sheepskin seat covers, have in all leather cars.

 

Need to put a DC ammeter on the negative battery cable. Are four possibilities that need to be instrumented properly

• bad battery not holding a charge
• bad alternator not charging properly
• bad wiring causing both of the above.
• "something" drawing over 50 milliamps steady when shut down.
• all/some of the above

 

Hi folks,

My dad's CTS 2008 has had a battery drain issue for some time now and I'm trying to figure out the source of the problem. If the car is driven every other day or, say, twice a week, we're good. If the car isn't driven for 5-6 days? The battery drops below the ignition requirement. The ignition switch is brand new, the starter has been replaced 2 weeks ago and the battery checks good. Now, there is a "repair airbag" message in the dash, and I was wondering if it could be linked. Any help will be appreciated

 

If the car is driven every other day or, say, twice a week, we're good. If the car isn't driven for 5-6 days? The battery drops below the ignition requirement.

The condition of the battery is still questionable in this scenario. There are varying degrees of "good battery", where some are good enough to pass a descent load test after a good charge, but not good enough to hold it in a parked car for more than a couple of days.

That was the indication for the last battery I replaced, where for that reason I never let the car sit for more than about 3 days without being driven, expecting possible difficulty with starting if I did. Make sure the current battery meets the minimum CCA requirement of about 730 CCA. The age of the battery is also important, since there's no mention of it having been replaced recently.

 

Agree with Joseph.
Has the battery been properly load tested?

 

I'd have your battery load tested and if you replace your car's battery...get at least as nice a battery as you had OEM...apparently CCA had changed over the years as mine had only 580 CCA and the AC Delco I replaced mine with is 680 but many other batteries (Clarios made Walmart EverStart Maxx or Interstate from Costco show 730 CCA and the Costco Interstate or the Walmart EverStart Maxx would be my choice...

Good luck with your car

Bill

 

Canadian Tire = Not the most knowledgeable service. I am not sure that I'd trust them to do a load test properly. That being said, there are good CT franchises with good people but most of them make Autozone look like mechanical geniuses.

 

I have seen the same problem with my car's battery, load test was fine battery, but the battery went dead.
I replaced the battery and no more problems.

Where does the car reside, and how old is the battery?

 

The battery is about 18 months old, it was a replacement under warranty for the previous AC Delco 48PG. The car spent all its winters inside a garage and was used in the snow a handful of times. Heck, I don't think it's been outfitted with winter tires in 5 years. Also, it has only 52k miles.

 

In general, GM specs the quiescent (everything off) at "under 50ma". Mine usually run 20-30ma.
The total battery load divided into its capacity its capacity will determine how long it lasts. 200 ma will kill most batteries in a few days.

 

with 18 months of a battery not being fully charged may be your problem. Just buy a new battery for a few bucks and see if that works. Cheaper than a technician doing a diagnosis.

 

I just bought a Delco, free shipping to my home and no exchange is good.

 

still a proponent of the AGM for our Gen2 CTS???...find a good deal on an AC Delco???...

Bill

 

so would you share with the class???...it is more helpful and appreciated...

 

$186+tx is pretty steep for a 36mo battery IMO.

 

especially for little to no benefit...

Bill

 

were I buying a new battery I would get the Everstart Maxx from Walmart as it appears to be the same as the Costco Interstate for about $10-12 less...I've not seen any other "premium" battery (36 month free replacement battery, plus highest CCA/CA RA) that beats that price...

YMMV...good luck with your choice

Bill

 

Any more I only buy AGMs. Have you priced 48/H6 AGMs lately ?

 

No need.
Nothing I own requires an AGM battery.

 

OTOH I keep cars I like for decades. I filnd AGMs last about twice as long as plain Maintenance free batteries in Florida.

 

Still have OEM battery in my 8 year old V Wagon. In Florida.

 

Amazon had the best deal for my needs/wants. Him do fit my coupe.