jwrichter

Is there a check battery light or something similar on the 05 sl 55? Thanks

B R

There is a battery icon that will show if it's low, & if the trunk battery is really bad, there will be a message that says something like electronic consumers offline.

alx

If you drive car daily, leave car for at least 2 days (dont drive it). After that enter engineering menu on the dash and check battery voltage. If below 12.5-12.7 volts- your battery is no good generally speaking. If voltage is above 12.5 it still could be bad, but it will require a battery tester to establish condition. Harbor freight has good cheap analog battery testers.

jwrichter

Alex, where exactly are you referring to?

alx

dont understand your question...

roberthechter

By pressing the correct sequence (reset ect.) the battery voltage will appear in the dash readout with car off (needs to be 12.5V or more) and you can start car and verify its charging (14.7V)
By letting the car sit for 2 days and seeing if voltage is above 12.5 will tell you if battery in trunk is good. As for the battery under the hood. Its for starting only, if it starts, its good

jwrichter

So what's the sequence? could you clarify a bit.....

Benz-O-Rama

Key to 2nd position - ON
Change DIC to show outside temp
Key off
Key to 1st position - ACC
Press reset button 3 times quickly and Voltage should be displayed

If you scroll through the DIC, you'll see options for:

Dynamometer Mode
Oil Level (in Liters)
Your VIN
And you can reset service interval


Can't remember what else is in there....

jwrichter

That didn't work for me, maybe a difference forom 05-06? Thanks for the reply anyway.

55slamg

the BIG red battery logo come on and "visit workshop" illuminate's on my 05 sl55 when I accelerate ( punch it down ) MB suspected the rear battery was defective as I told them that the battery tender takes awhile to go green when plugged in compared to the front battery tender ( i figured this out after that they are two different sized battery ). Replaced the rear battery with new one and it never fixed the problem. MB says bring it in as they need to due 1.5hrs of checks to find problem. They think it may be a regulating module, a non-MB mechanic thinks it could be a pulley slipping. Anyone here have any thoughts of what may be causing this malfunction error?

B R

Sounds like voltage regulator to me. I just replaced mine last month. Got a new one from NAPA for $60 (had to order, took a week), and everything is back to normal.

Benz-O-Rama

Nope. I have an 05, and it works like a charm. You are hitting the hard reset button on the instrument cluster, right? Every once in a while, I have to hit my reset button 4 times....

Here's a vid

http://www.youtube.com/watch?v=xFHlDn-hw1s