W211 Battery warning

[Diesel Benz]

A reminder there is a readily available Voltage display.

With key in position I (before everything lights up) and speed display up press trip reset button rapidly three times. Should get a single beep.

Go to next key position and using up & down arrows you will find that a Voltage display is in there as well as speed, temperature etc. (Also another info screen but now displays oil level in litres but right now cannot recall if that is a sub-menu)

Have you figured out if this voltage reading is for the main battery or would it be the lower of the two? So far I've assumed one needs to use a multimeter to find out if both batteries are good.

 

[Alps]

even mine done this the other day after two weeks of not driving her, as Jay said its perfectly normal.

 

[Gollom]

A reminder there is a readily available Voltage display.

With key in position I (before everything lights up) and speed display up press trip reset button rapidly three times. Should get a single beep.

Go to next key position and using up & down arrows you will find that a Voltage display is in there as well as speed, temperature etc. (Also another info screen but now displays oil level in litres but right now cannot recall if that is a sub-menu)

Tried this but nothing - mine is a 2006 pre facelift. ANy ideas?

 

[Diesel Benz]

Tried this but nothing - mine is a 2006 pre facelift. ANy ideas?

Did you have all your doors closed? If I remember right, you have to have the hood, trunk and doors closed to gain access to the service menu and the voltage reading appears on the way to the service menu.

 

[RoddersC4]

I am still getting the fault on my car, is the small battery user changeable and any idea of the cost?

I had my auxillary battery changed last year and IIRC it was approx £75 for the part the garage fitted it for free as it was in for a 3rd party warranty claim

its situated IIRC under the cover in front of the windscreen driver side

 

[moonshine]

Your battery problem could be one of two problems we regulary see and they are a software upgrade for the BCM and the cables to the Aux. Battery break underneth the battery mounts.

 

[Diesel Benz]

Your battery problem could be one of two problems we regulary see and they are a software upgrade for the BCM and the cables to the Aux. Battery break underneth the battery mounts.

I have not heard about AUX battery cables being an issue, can you tell more about that. Or are you referring to the AUX battery isolator relay? The relay is better known for issues. The BCM SW and the AUX battery itself are other known issues as you say.