R-Class (W251) Produced 2006-2013: R320CDI, R350, R420CDI, R500

Dead battery-Keyless go does not work and key will not unlock door.

Old Nov 1, 2013 | 08:06 PM
  #1  
Brian425's Avatar
Thread Starter
Junior Member
 
Joined: Aug 2013
Posts: 28
Likes: 0
From: Brooklyn, NY
2007 R63, 2012 BMW X5 50i (Dinan Stage 2 and AR Designs downpipes)
Exclamation Dead battery-Keyless go does not work and key will not unlock door.

I have a 2007 R63 with a dead battery. The keyless go will not work. I tried to use the metal key in the remote. It turns; but, it does not unlock the vehicle. I believe I left the lights on. I am assuming the aux battery is dead also.

Any idea on how to open the vehicle or the hood. I would prefer not to do any damage if possible.
Reply
Old Nov 1, 2013 | 10:16 PM
  #2  
Brian425's Avatar
Thread Starter
Junior Member
 
Joined: Aug 2013
Posts: 28
Likes: 0
From: Brooklyn, NY
2007 R63, 2012 BMW X5 50i (Dinan Stage 2 and AR Designs downpipes)
Success!!! The key probably has not been used in years. I turned the key and gave the handle a few quick tugs and it opened.

Looks like I will be replacing the aux battery and testing the main battery.
Reply
Old Nov 2, 2013 | 09:25 AM
  #3  
efzauner's Avatar
Super Member
15 Year Member
Photogenic
Liked
Loved
 
Joined: Jul 2009
Posts: 938
Likes: 53
From: Montreal, Canada
2005 C240 2011 R350
Moral of the story.. Keep your door locks oiled!
Reply
Old Nov 2, 2013 | 10:16 AM
  #4  
Spud_Racer's Avatar
Member
 
Joined: Dec 2012
Posts: 168
Likes: 0
From: Connecticut
R500 + SLK55 AMG
Originally Posted by Brian425
Success!!! The key probably has not been used in years. I turned the key and gave the handle a few quick tugs and it opened.

Looks like I will be replacing the aux battery and testing the main battery.
I had the same issue recently. My R500 has an intermittent current drain that can leave the battery dead if the car sits for a week or more. So, when it pulled this trick a few weeks ago, like you I thought no problem, I'll just use the physical key to open the door. And like you it didn't work at first. It took a few seconds and attempts to get the lock cylinder to respond to the metal key. I haven't done it yet but maybe a squirt of WD40 is in order.
Reply
Old Feb 9, 2016 | 08:08 PM
  #5  
hoda's Avatar
Newbie
 
Joined: Feb 2016
Posts: 1
Likes: 0
2006 mercedes R350
Smile 2006 Mercedes R350 entry with a dead batter

Originally Posted by Brian425
Success!!! The key probably has not been used in years. I turned the key and gave the handle a few quick tugs and it opened.

Looks like I will be replacing the aux battery and testing the main battery.
Thank you Brian425 for your post. it helped. my husband left some of the lights on and the battery drained, we were not sure of what to do until you found this post. the metal key and the remote won t open the car, I have tried putting the metal key in and out while giving the handle few tugs and ....boom chika boom...Success. I was so happy that I have succeeded in something my husband was afraid to do
Reply
Old Feb 9, 2016 | 09:15 PM
  #6  
Brian425's Avatar
Thread Starter
Junior Member
 
Joined: Aug 2013
Posts: 28
Likes: 0
From: Brooklyn, NY
2007 R63, 2012 BMW X5 50i (Dinan Stage 2 and AR Designs downpipes)
Glad it helped Hoda.

You can buy graphite any place they cut keys. Put a little in the lock and in the key once a year and open the door with the key. $1.99 well spent.
Reply
Old Jun 21, 2016 | 09:14 AM
  #7  
Prerna's Avatar
Junior Member
5 Year Member
Liked
Loved
Community Favorite
 
Joined: Jan 2016
Posts: 65
Likes: 4
2008 R500 5.5 l
Having the same problem and could also open it by trying and insisting. Strange system...

Now my problem is that my battery is totally dead after 3 1/2 weeks abroad. Not a single light, so I decided to charge the battery. It's been several hours now, but it doesn't seem to charge at all.

I also tried to jump it with my wife's car. Power came (lights, etc.) but not enough to start the engine

Anyone has a clue and advice?
Reply
Old Jun 21, 2016 | 03:40 PM
  #8  
ghenry's Avatar
Member
15 Year Member
 
Joined: May 2010
Posts: 89
Likes: 8
From: Gautier Ms
2008 R350, 2024 Subaru Legacy,2018 Chevy Colorado
Originally Posted by Prerna
Having the same problem and could also open it by trying and insisting. Strange system...

Now my problem is that my battery is totally dead after 3 1/2 weeks abroad. Not a single light, so I decided to charge the battery. It's been several hours now, but it doesn't seem to charge at all.

I also tried to jump it with my wife's car. Power came (lights, etc.) but not enough to start the engine

Anyone has a clue and advice?
I believe your main battery is toast. If you replace it be sure to change out the aux battery while the floor is up. The main battery is a group 49.

Gary
Reply
MB World Stories

The Best of Mercedes & AMG

story-0

6 Mercedes Models That Did NOT Age Well (But Are Somehow Still Cool)

 Verdad Gallardo
story-1

Manual Mercedes? 6 Times Sindelfingen Let Drivers Have All The Fun

 Verdad Gallardo
story-2

Mercedes SLR McLaren 722 S Is Extremely Rare Example Modified by McLaren

 Verdad Gallardo
story-3

8 Classic Boxy Mercedes Designs That Have Aged Like Fine Wine

 Verdad Gallardo
story-4

Flawlessly Restored Mercedes 190E Evo II Heads to Auction

 Verdad Gallardo
story-5

Electric Mercedes C-Class Unveiled: 11 Things You Need to Know

 Verdad Gallardo
story-6

Mercedes EQS Gets A Major Update: Everything You Need to Know

 Verdad Gallardo
story-7

5 Underrated Mercedes-Benz Models That Don't Get the Love They Deserve

 Verdad Gallardo
story-8

Mercedes 300D Has Pushed Well Past 1 Million Miles and It Ain't Stopping

 Verdad Gallardo
story-9

10 Most Reliable Mercedes-Benz Models You Can Buy Used

 Verdad Gallardo
Old Jun 21, 2016 | 04:34 PM
  #9  
Prerna's Avatar
Junior Member
5 Year Member
Liked
Loved
Community Favorite
 
Joined: Jan 2016
Posts: 65
Likes: 4
2008 R500 5.5 l
Originally Posted by ghenry
I believe your main battery is toast. If you replace it be sure to change out the aux battery while the floor is up. The main battery is a group 49.

Gary

Welk, I changed both batteries 1 month ago.
Reply
Old Jun 22, 2016 | 02:08 PM
  #10  
Brian425's Avatar
Thread Starter
Junior Member
 
Joined: Aug 2013
Posts: 28
Likes: 0
From: Brooklyn, NY
2007 R63, 2012 BMW X5 50i (Dinan Stage 2 and AR Designs downpipes)
Since the battery is so new, you must have some kind of parasitic draw on the battery. Once a battery is stone dead, it can be hard to jumpstart them.

Good luck.
Reply
Old Jun 23, 2016 | 02:25 PM
  #11  
gforaker's Avatar
Member
10 Year Member
Liked
 
Joined: Jan 2011
Posts: 203
Likes: 21
From: Doylestown, OH
2015 Audi S4, 1982 Fiat Spyder, 2010 R350, 2013 E550 Cabriolet
Also, if you could not jump start it, you must be doing it wrong. Make sure you have a good, clean connection on both cars to the correct spot. I have had similar trouble in jump starting cars in the past and it was always due to a not clean contact.
Reply
Old Jun 27, 2016 | 02:34 AM
  #12  
Prerna's Avatar
Junior Member
5 Year Member
Liked
Loved
Community Favorite
 
Joined: Jan 2016
Posts: 65
Likes: 4
2008 R500 5.5 l
Originally Posted by ghenry
Since the battery is so new, you must have some kind of parasitic draw on the battery. Once a battery is stone dead, it can be hard to jumpstart them.
Also, if you could not jump start it, you must be doing it wrong. Make sure you have a good, clean connection on both cars to the correct spot. I have had similar trouble in jump starting cars in the past and it was always due to a not clean contact.
I eventually managed to get it started after some struggle: I had to jump it and leave it "charging" like this for around 20 minutes, until there was enough power to start it. Looks like when a battery is completely dead, jumping it is not necessarily sufficient. Or one might need a similar car with strong alternator, I don't know really. But I'm glad it started, I did let the engine run and drove a bit for two hours, and then tried to charge it again. This time the charge went fine.

Last edited by Prerna; Jun 27, 2016 at 02:39 AM.
Reply
Old Jun 28, 2016 | 10:56 AM
  #13  
Brian425's Avatar
Thread Starter
Junior Member
 
Joined: Aug 2013
Posts: 28
Likes: 0
From: Brooklyn, NY
2007 R63, 2012 BMW X5 50i (Dinan Stage 2 and AR Designs downpipes)
You either have a parasitic draw or a bad alternator/regulator. Simply charging the battery will not solve the issue.
Reply
Old Jul 6, 2016 | 06:06 AM
  #14  
Prerna's Avatar
Junior Member
5 Year Member
Liked
Loved
Community Favorite
 
Joined: Jan 2016
Posts: 65
Likes: 4
2008 R500 5.5 l
Originally Posted by Brian425
You either have a parasitic draw or a bad alternator/regulator. Simply charging the battery will not solve the issue.
Hi Brian,

Very much right. Actually I forgot to mention an important fact: I found what must have been the culprit. I had let an OBD Bluetooth device in the diagnosis plug. I hope it's just that. So far the charge seem to hold, even though I haven't let the car more than 3-4 days without use since the incident.
Reply

Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 

Thread Tools
Search this Thread
Rate This Thread
Rate This Thread:
You have already rated this thread Rating: Thread Rating: 1 votes, 5.00 average.


All times are GMT -4. The time now is 08:11 PM.

story-0
6 Mercedes Models That Did NOT Age Well (But Are Somehow Still Cool)

Slideshow: Not every Mercedes design becomes timeless, some feel stuck in the era they came from.

By Verdad Gallardo | 2026-05-12 18:09:07


VIEW MORE
story-1
Manual Mercedes? 6 Times Sindelfingen Let Drivers Have All The Fun

Slideshow: Yes, Mercedes built manual cars, and some of them are far more interesting than you'd expect.

By Verdad Gallardo | 2026-05-02 12:36:58


VIEW MORE
story-2
Mercedes SLR McLaren 722 S Is Extremely Rare Example Modified by McLaren

Slideshow: A one-of-one U.S.-spec Mercedes-Benz SLR McLaren Roadster became even rarer after a factory-backed transformation at McLaren's headquarters.

By Verdad Gallardo | 2026-04-29 11:19:28


VIEW MORE
story-3
8 Classic Boxy Mercedes Designs That Have Aged Like Fine Wine

Slideshow: Before curves took over, Mercedes mastered the art of the straight line, and some of those shapes still look right today.

By Verdad Gallardo | 2026-04-25 12:05:49


VIEW MORE
story-4
Flawlessly Restored Mercedes 190E Evo II Heads to Auction

Slideshow: The 190E Evolution II shows how a homologation necessity became a six-figure collector icon.

By Verdad Gallardo | 2026-04-22 17:53:47


VIEW MORE
story-5
Electric Mercedes C-Class Unveiled: 11 Things You Need to Know

Slideshow: Mercedes is turning one of its core nameplates electric, and the details show just how serious this shift is.

By Verdad Gallardo | 2026-04-21 13:58:06


VIEW MORE
story-6
Mercedes EQS Gets A Major Update: Everything You Need to Know

Slideshow: Faster charging, longer range, and a controversial steer-by-wire system define the latest evolution of Mercedes-Benz EQS.

By Verdad Gallardo | 2026-04-15 10:35:34


VIEW MORE
story-7
5 Underrated Mercedes-Benz Models That Don't Get the Love They Deserve

Slideshow: These overlooked Mercedes-Benz models never got the spotlight, but they quietly delivered more than most remember.

By Verdad Gallardo | 2026-04-13 19:35:45


VIEW MORE
story-8
Mercedes 300D Has Pushed Well Past 1 Million Miles and It Ain't Stopping

Slideshow: A well-used 1991 Mercedes-Benz 300D with more than one million miles is now looking for a new owner, and it still appears ready for more.

By Verdad Gallardo | 2026-04-10 10:05:15


VIEW MORE
story-9
10 Most Reliable Mercedes-Benz Models You Can Buy Used

Slideshow: From bulletproof sedans to surprisingly tough SUVs, these Mercedes models proved that the three-pointed star can go the distance.

By Verdad Gallardo | 2026-04-08 09:55:49


VIEW MORE