vezePilot

I found a procedure for displaying the OBD Codes of the DIC at SuperChevy.com, but it is for a C5. How do I display codes on my 2007 C6 3LT A6?
(I did a forum search but it didn't seem to have threads for this issue.) I would like to check for any error codes before I replace the battery.

Mordeth

You need a very cheap OBDII scanner and a free application on your cell phone. The OBDII scanner can be purchased from Amazon for $20 - $30. It plugs into your OBDII port and communicates with the program on your cell phone via bluetooth. I use Torque. It is a free app you can get from Google play. There are other free applications. The process is simple and cheap and the scanner is good to have around.

Do you have a check engine light on? Are you experiencing some issues where you think a code was stored? Replacing the battery does not require checking or clearing any codes. Just make sure you re-index the windows when done.

vezePilot

Thanks, Mordeth. No, there is no light on and no errors that I know of. Just kinda wanted to know for sure, because others have posted difficulties resulting from simply replacing the battery. I have also seen on more than one site that it may be a good idea to provide the computers with a "hard reset" ... when the Battery is COMPLETELY DISCONNECTED, by touching the positive and negative cables together. With modern electronics operating at voltages below 5 VDC, for example at 3 VDC and such, it makes sense to bring the system voltage all the way to zero for the reset. And only then to connect the new battery.
This 2007 3LT A6 is just so flawless, I would really like to keep it that way.

Mordeth

Here is the scanner I use:
It is compatible with Android devices. If you have an I-phone then there is also one for that.

Download a free application on your phone like Torque (there are others). Then you plug the unit into the OBDII port below your dash (driver side). You then pair the device to your phone and then open the application on your phone. It will now be connected to your car. You can view various parameters about your car and engine, and display any stored codes. The scanner is also good to just have around in case you ever get a check engine light and want to know the code. It doesn't display on the DIC like C5s did. You need a scanner.

But again, it isn't necessary in order to change the battery. I literally disconnect my battery every 2-3 weeks for various reasons when I am working on my car. Never once is there an issue. Never. As far as touching the positive and negative cable together - yes this will discharge fully all of the capicitors and reset various systems. But it isn't necessary. Wear gloves then simply remove the negative cable from the battery, then the positive and then remove the old battery. Then place the new battery in the compartment, secure it, connect vent hose if battery is vented and reconnect the battery, starting with the positive cable first.

Then start car, re-index the windows and enjoy. You will have no problems or issues with this procedure.

Dano523

Basic scanner will only read and clear basic trouble codes,
To get deep into the abs and body modules to check for problems there that may not pop up as basic codes, takes something like a Tech II to pull and reset such codes instead.

As touching the positive and negative batteries together once the battery has been removed, it just drain the last of the module power quickly, very having to wait a few mins for the modules to drain off the last of the power they have been holding isntead for a hard reset of the modules.