My 2006 E320 CDI has started showing "Lo Batt. unconven. functions will be turned off" perhaps due to lack of much driving. When I take the car for a long drive, the message would go away. However, the stealership today determined the aux battery needs replacement. Is it easy to do so oneself? Also, is it necessary to replace the system batt at the same time as replacing aux?
Last edited by terracotta; 02-02-2012 at 01:43 AM.
I just did this myself last weekend. Bought the battery at Walmart (same glass mat battery as everywhere else). It comes dry, you have to add the acid, let sit for 1 hour, then charge before installing (according to the directions)
Steps: (after prepping battery)
1. Disconnect main battery's neg cable in trunk. (Good time to check spare, mine only had 11lbs of air!!)
2. Remove Pollen filter assembly, one 10MM nut and 3 plastic pins
3. Disconnect Neg and Pos cables from Aux battery
4. Remove nut holding battery in place.
5. Install new battery, and hook up cables ( I did reuse the red POS cover)
6. Tighten mounting bracket
7. Install Pollen filter, make sure seal is fit properly.
8. Connect Neg Terminal on main battery in trunk.
9. Reset Windows and sunroof. (hold down buttons until fully opened and closed one time each)
There is a really complete thread on the subject for you to study as I just did mine recently.
New in 2006? It was about time, wasn't it?
My CDI was built in November 2004 and put into service in February, 2005.
That little battery lasted for over 109,750 miles 'til perhaps December 17, 2011.
Maybe it had failed earlier and the original owner discovered that
he could ignore the warning and simply 'motor on'?
That's when it became our daily driver; In fact our only vehicle.
My 2006 E320 CDI has started showing "Lo Batt. unconven. functions will be turned off" perhaps due to lack of much driving? [No, no!]
When I take the car for a long drive, the message would go away. However, the stealership today determined the aux battery needs replacement.
Is it easy to do so oneself? [YES, yes!] Also, is it necessary to replace the system batt at the same time as replacing aux? [No, no!]
If I, an old duffer, the oldest one here, can do it, so can you. Really, it is so easy!
Think of how you will feel after you are done and have saved upwards of $100?
The URL is posted below your first message. When you have read it all,
you should know more about the subject than your stealership! Be sure and read it in its entirety, the whole enchilada, all twelve pages, 285 messages.
Good luck and love that feeling of accomplishment! Saving money is so much fun, isn't it?