Cadillac CTS-V Forum banner
1 - 5 of 5 Posts

·
Registered
Joined
·
367 Posts
Discussion Starter · #1 ·
Where is the backup battery located in the 2013 CTS V? I found the 4G replacement offered in Canada for the OnStar and once you get one you have to disconnect the battery and the RAP battery before replacement. Just getting ready for the change out in the coming months. That is, before OnStar goes away January 1st.
 

·
Registered
Joined
·
4,006 Posts
Where is the backup battery located in the 2013 CTS V? I found the 4G replacement offered in Canada for the OnStar and once you get one you have to disconnect the battery and the RAP battery before replacement. Just getting ready for the change out in the coming months. That is, before OnStar goes away January 1st.
You use OnStar and bound and determined to keep it? Interesting.
 

·
Registered
Joined
·
367 Posts
Discussion Starter · #3 ·
Canada already has the 4G fix. GM says we can't get it due to the ship shortage. Anyway, it is just an OnStar box behind the glovebox. But, you have to have the battery disconnected along with the backup lithium battery in order to install it and not screw up the OnStar.


I can find the battery backup on eBay but cannot find the location. On my friends Mercedes it is on the drivers side behind the cluster. New cars with CAN bus architecture like to have retained power. Our BCM sits on the drivers side above your right foot. Anyway, still looking for the backup battery location. Might order the OnStar from Canada. I don't use it but it would be nice to have the car disabled when it gets stolen. I live in Las Vegas and this is one of the more popular ones to steal. Just the drivetrain, that is...
 

·
Registered
Joined
·
2,478 Posts
It doesn't look like you actually need to care where the battery is, unless it's already dead. The instructions explain that the backup battery will be activated if power is removed from the OnStar module while the ignition is on or RAP is on. The backup battery is intended to allow OnStar to continue to work if power is lost when the car is "running", like if you crash and the 12V main battery gets disconnected. As long as the ignition is off and RAP is off (which happens as soon as you open the door after turning off the ignition), you can disconnect the OnStar module without regard to the back up battery. It won't be activated and so, will be as good after the OnStar upgrade as it was before the upgrade.

Also, the comments and image in the instructions you linked to above imply the backup battery is plugged in to the back of the module per the red circled "1" on pages 11-12 (which, BTW, is logically the best place for it since it ensures the module gets power in a wreck unless that section of the car is destroyed).

I would note that it also appears you need to reprogram the new module after installation and you'll be needing a Tech-II for that.

And lastly, depending on how you want to read the preamble, it looks to me like successfully replacing the module is only half the task. GM may only be providing the back-end OnStar support for vehicles it knows have been officially upgraded. You go through all the trouble of replacing your module and it might not get you anywhere unless GM is willing to "relist" your vehicle for the service which I'm betting is possible but will be like pulling teeth.
 
1 - 5 of 5 Posts
Top