rRambo

Hi everyone,

I recently purchased a W220 S430 and a couple of days ago my battery died. I seem to be having the same problems as lots of other people have had - namely I can't open the boot remotely (due to no power) and my mechanical key won't turn the trunk lock (but will turn the main door lock).

I decided to try and connect a 12v battery to the connection located in the passenger footwell per maliktoronto's method in this thread - https://mbworld.org/forums/s-class-w...tart-help.html.

However, when I pulled up the carpet and floor plate I'm faced with something that looks quite different to what I've seen in other pictures and posts (my pic is below).

Can anyone shed some light on why my setup might be different and if so, if there are any other areas to try getting power into the car to get the trunk open? If it's relevant my car is a right hand drive.

Thanks in advance guys,

rRambo

tusabes

if your car is right hand drive the jump point might be under the drivers side footwell

ibeforreal

Maybe this video will help. However since you have right hand drive everything might be the opposite. In other words, the jump point might be on the passenger side.

rRambo

Thanks guys - I was assuming the cables were in the "passenger side" footwell (whatever side this is on) but I think you might be right that the cables are in the right hand front footwell (regardless of whether the car is right hand drive or left hand drive). Elc-sun in this thread (https://mbworld.org/forums/s-class-w...ml#post4046665) at post number 8 posts a picture of the cables I'm looking for and says they're in the front right footwell and I can see pedals. I'll have a look tonight and report back.

Thanks

rRambo

rRambo

Well after finally getting the carpet up and out past the pedals I'm glad to say that the cables were there! Managed to hook up a jump pack and get the boot open. Got the car started but battery is dead so will get it replaced. Still can't get the key to turn in the boot lock - does anyone know if there's a way to loosen the lock once it's open (other than wd40)? I'd like to be able to use the key to get to the battery if it ever dies in the future.

ibeforreal

Glad to see you get it open. Are you turning the metal key counterclockwise? You might have to sort of push it up a bit.

tusabes

Yeah keep fiddling with the lock, you have to turn it and push it just right, most people don't turn it the correct way to open it .

A quick trip to a Mercedes dealer will have someone there to teach you the trick to opening it

wallyp

Be aware - Turning the key one way opens the boot, turning it the other way kills the electrical/pneumatic opening. This is so the folks at valet parking can't get into the boot...

rhswest

I just tried the steps in the video posted in this thread. It works even for W211 models.

My situation:
1. Dead battery in trunk.
2. Trunk is locked and cannot be unlocked from the inside door-panel trunk switch.
3. I don't have the metal key, so I can't just plug it into the key latch.

What I did:
1. Pulled the rug back on the passenger footwell.
2. Removed the three 10mm plastic nuts that was holding the metal plate.
3. Connected a Positive Jumper Cable in my W211 to the thick black battery wire shown in the video.
4. Connected the Positive and Negative cables to the source car's battery (a running car).
5. Connected the Negative cable in my W211 to the ground shown in the video.
6. Tried the door-panel switch to open the trunk, and it worked!!!

rRambo

Glad to hear it! On UK models it's a bit harder to access due to being on our driver side with pedals in the way!

ibeforreal

Always great when a plan comes together.

wallyp

After reading several of these threads, I think that it would be a very good idea to learn how, and/or do the repairs necessary, to open the trunk with the metal key before you have a dead battery...

mercedesdriver2

tried the uder passenger seat side floor ,charge didn't work this time. to open trunk, like it did months ago (.Winter now was summer first time) dealer came out and pulled fuse box on passenger side hooked up to a point under it and trunk opened, then charged from the rear battery. car started but flashers and interior lights flashed. disconnected battery when got home, putting charge on over night. hope that resets alarm? one site said it would. plus battery needs full deep charge. and wouldn't with the lights flashing. . really stupid of MB not to have positive jump point under the hood those S class years !

Astro14

Disconnecting the battery won't reset anything on this car.

But you will now have to reset several things: windows, sunroof, stability sensor. See your owner's manual for details.

And how did your key "not" open the trunk? Are you certain that you were turning it the correct direction? Turning it far enough? Mine has opened the trunk when this has happened to me. You have to turn the key 120 degrees. It takes some finger strength as you overcome the lock actuator, but it works every time.

wallyp

Basically, you caused most of the new problems by allowing the battery to go dead or by disconnecting the battery, and you will have to fix them by doing the required resets. These resets include:
- With the engine running, turn the steering wheel all the way to the left stop, then all the way to the right stop.
- Lower the driver's window to the bottom by pushing the switch thru the detent (auto lower position), and hold the switch for five seconds, then raise the window to the top by pushing the button thru the detent (auto raise) and hold the switch for five seconds. This resets the window by telling the computer where the bottom and top are.
- Repeat this for every window.
- Repeat this for the sunroof.
- Repeat this for raising and lowering the steering column.
- Repeat this for moving the steering column in and out.
- Repeat this for moving the seats forward and back.
- Repeat this for moving the seats up and down.
- Repeat this for moving the headrests up and down.
- Repeat this for moving the backrests back and forth.
- Repeat this for opening and closing the power trunk if your car is so equipped.
- Try to remember that you should try to avoid allowing the battery to go dead and disconnecting the battery unless it is really necessary.