katlinb

Hello, the battery in my 2004 E320 went completely dead after I foolishly left the keys in the ignition with the phone charging overnight. The key would not turn in the ignition to start the car at all. My husband jump started the car, and now it is running fine and all convenience functions are working, but there is a pesky red "Visit Workshop!" message with a drawing of a battery in the dash. He connected all the cables correctly when he jumped it, although he first tried hooking it up to the battery in the trunk and then, when that didn't work immediately, connected his car's battery to the appropriate hookups under the hood of my MB. The key was then able to turn in the ignition and the car started. Any idea what might be wrong? The dealer wants $145 to diagnose it, and my good, independent mechanic tried today but was unable to read the codes with his machine.
The battery is only about 1.5 years old and still under warranty, I was thinking of going by Advance Auto Parts and asking them to check it for charge, but I do think it is fine as the car has plenty of power and has been starting and driving fine the last few days since the jumpstart.
Thank you so much for any insight you can offer!!
-Kathleen

Plutoe

Jumping a battery ain't like jumping an MB installed battery anymore.

As you learned your trusted indy just does not have the diagnostic equipment to resolve your issue with the battery control module.

You need someone with DAS Xentry diagnostic software to read and correct the issue or it's the dealer.

katlinb

So you think that the problem is with the battery control module? I had the battery and the alternator tested today and both passed the test, but the battery had too high a charge in it. So it sounds like it is some kind of voltage regulator issue, I guess that is controlled by the BCM. I hope that it is not another expensive repair!!

Plutoe

That is my thought, however you are spending money needlessly----you need a diagnostic scan that tells you what the problem is

katlinb

Ok, thanks very much for the insight. I hadn't spent any money on it yet, unless you consider time to be money. I brought it to a different workshop today for an official diagnostic scan. It turns out that the computer control needed to be rebooted or whatever so that it would work properly.
-Kathleen

DanG2

And if you do this, https://mbworld.org/forums/e-class-w...er-always.html, you won't need to have the key in the ignition to charge the phone, so it shouldn't happen again.