W211 Battery Protection: Convenience functions temprarily unavailable

[rob_miller]

Over the last month my 2004 E320 starting coming up with 'Battery Protection: Convenience functions temporarily unavailable'. The message usually goes after 10 mins of driving but it is appearing much more often.

When the key is in position one the voltage is reading 11.5V on the dash. When starting the vehicle the voltage drops to 8.7V, is this normal?
Also when the engine is running the voltage is measuring 12.9V, seems a bit low.

Just wondering if it is time for a battery change seeing as it is the original but not too sure which battery is causing the problem.

Thanks in advance for your help.

 

[pmcgsmurf]

Both our 2004 220 CDi had to have new batteries last month.

Had been increasingly showing the Convenience Function error.

 

[rob_miller]

how much did it cost you for the batteries?

I just hope that it is the battery and not something big like the alternator

 

[pmcgsmurf]

how much did it cost you for the batteries?

Free, long story to do with springs.

Don't buy from the dealer, either go to a commercial dealer or buy online.

Do a search lots of discussions on batteries and where to get them and for that matter which are best.

 

[Stratman]

With the engine running the battery voltage should be about 13.8V, and not running about 12.6V or thereabouts.

Your figures could well be indicating a shorted cell. New battery time.

 

[rob_miller]

I guess the dealer would be too expensive.
I'll take your advice and go to a comercial dealer where know i won't get ripped off.

 

[rob_miller]

With the engine running the battery voltage should be about 13.8V, and not running about 12.6V or thereabouts.

Your figures could well be indicating a shorted cell. New battery time.

Which battery could be causing it?

I've had the battery recharged and alternator checked twice at a mb dealer. £125 each time.
This time i will not get the battery replaced by them.

 

[pmcgsmurf]

Which battery could be causing it?

I've had the battery recharged and alternator checked twice at a mb dealer. £125 each time.

I think I'd be back at the dealer, you'd think for £250 they could check the battery, determine it's faulty and fit a new one.

They should have done this for half the price.

 

[rob_miller]

I think I'd be back at the dealer, you'd think for £250 they could check the battery, determine it's faulty and fit a new one.

They should have done this for half the price.

When i went to them the second time i insisted that they change the battery but they said there was no need and that it just needed a good charge. The message only went away for a couple of days.

It must be one of their ways to get more money out of the customer.

 

[m7m]

Which battery could be causing it?

I've had the battery recharged and alternator checked twice at a mb dealer. £125 each time.
This time i will not get the battery replaced by them.

Why pay the dealer when there are many battery-selling places offering FREE battery check? They do it in front of you, while you wait. Worth checking that it is free even if you don't buy a battery from them.
As for recharging, I bought a battery charger which is not expensive and has proved very useful when I did not use the car for a long time.

 

[cyberflex]

Also when it comes to getting a new battery, I used the varta online tool (go to their website) to find out the EXACT battery my C320 needed, I then went to a Varta dealer and picked it up for approx £97, also Halfords now stock the Bosch range and Eurocarparts do the Exide range, cannot go wrong with any of the above in terms of quality.

 

[rob_miller]

I got the battery changed last week at the dealer. They charged £75 as they had already charged me twice for a recharge so that was not too bad.

Now im getting a new problem when trying to activate SBC Hold. When in traffic i do what i used to do which is depress the brake pedal and then press it hard but a message comes up on the dash saying 'SBC H cannot be activated, see owners manual'.

Just wondering if anyone knows what the problem could be.