How to Replace your Mercedes-Benz E-Class W211 Auxiliary Battery
Is there an Auxiliary Battery Malfunction message on the dashboard of your Mercedes-Benz? This guide will show you how to fix the issue on Benz cars from 2003 through 2009, specifically Mercedes-Benz E-Class W211 automobiles, including the E320, E350, E500, E55 AMG, and E63 AMG.
Are you more of a visual learner? Follow along with our video guide below!
Replacing an Auxiliary Battery
Symptoms
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- An auxiliary battery malfunction message on your dashboard
- a “Battery protection: Convenience functions are temporarily unavailable” Message on your dashboard
What you will need
- W211 Auxiliary Battery
- 10mm deep socket
- Ratchet wrench
- Battery Terminal Protector
Procedure
- Open the hood and locate the auxiliary battery on the passenger side of the engine bay.
- Remove the 10mm plastic nut from the cabin filter housing.
- Remove the 10 mm nut from the top bracket. Lift the bracket.
- Remove the 10mm bolt from the negative (-) terminal.
- Remove the 10mm bolt from the positive (+) terminal. DO NOT let the positive cable come in contact with anything metal.
- Remove the old battery and install the new one. Connect the positive cable first and then the negative cable last. Spray the battery terminal protector on your battery terminals to prevent corrosion. Install the cabin filter lid.
No programming or coding is required. Once you replace the battery on your W211 E-Class, the warning message should disappear from the dashboard.
We hope you found this guide helpful. For more troubleshooting tips, check out our other troubleshooting and repair guides!.
What’s the model number for a axillary battery for 2003 e320
Very good step by step guide. Thanks for sharing.
My local shop wanted $195 to replace the auxiliary battery on my 2005 E500. This is so easy I plan on doing it myself.