E220 Boot Won't Open As Car Battery Disconnected

[kevster]

Hi there,
I have a 2004 E220 CDI (W211). Yesterday, I depressurized the SBC braking system by disconnecting the battery (located in the boot/trunk of the car) in order to do some maintenance on the front disc brakes. I closed the boot when it started to rain. Now I am unable to open the boot with either the electronic fob or the key which can be detached from fob.

Any suggestions?

Thanks,
Kevin

 

[grober]

Get a set of jump leads and power the car systems by connecting the positive lead to the the main cable feed to the starter solenoid [ its always live] and the negative lead to a good chassis earth. This should permit you to open the car.

 

[kevster]

Hi Graeme,
Thanks a million.
I may have to do this from beneath the car as the bonnet/hood is closed and won't open either.

Kev

 

[grober]

Make sure you connect to the correct solenoid terminal! As a safety measure connect the jump leads to the car you need to power first [ THE ONE YOU NEED TO GO UNDERNEATH] before connection to "the donor" battery

 

[Auto-mobile]

I suggest you don't disconnect the battery to work on sbc.

Door shut, window down, key in ignition with it off.

Don't cycle ignition and don't open the door whilst working on the brakes.

 

[kevster]

Thanks for the tip Auto-mobile

 

[Lyserman]

Why won't the bonnet open?
It is purely a mechanical latching mechanism.

 

[Major774]

Have you definitely turned the valet key and pulled the latch in order to open the boot manually?

 

[kevster]

Lyserman, you are correct. I was getting mixed up with the boot! I can indeed open the bonnet using the lever under the dashboard.

Major774, I've tried several times with the valet key, to no avail. There is no budge even from the latch.

Now that I've the bonnet open, I'm going to try and research to see if there's a way of powering the car from within the engine bay. I see a red wire which seems to be bringing power to a fuse box, at the back left (driver's side) of the engine bay.

I want to try to exhaust other options first before I try to power the starter solenoid (not quite sure where it is and there's all those splash shields to screw off underneath).

 

[kevster]

Hi guys,
I've tried Major774's suggestion again and I've managed to get the boot open! I inserted the valet key, turned it anti-clockwise and kept trying to move the latch until it freed. And I was then able to open the boot.

Glad I could sort it this way.

Thanks for all the help and suggestions.

 

[Lyserman]

For future reference:
Open bonnet and, facing the engine, remove the fuse box lid on the left side, inside there you will see a red cable ending in a nut. Connect the 12v power supply +ve lead to that and the -ve lead to an earth point. That will power up the system enough to unlock the boot.

 

[pmcgsmurf]

Isn't there a second aux. battery for the SBC unit under the bonnet?

 

[kevster]

I think I remember seeing this hidden away beneath the cabin filter housing. So, opening the bonnet and facing the engine it is located on the right hand side of engine bay.

 

[Lyserman]

That is known as the auxiliary battery and will not power the boot lock if the main battery is disconnected.

 

[Major774]

Hi guys,
I've tried Major774's suggestion again and I've managed to get the boot open! I inserted the valet key, turned it anti-clockwise and kept trying to move the latch until it freed. And I was then able to open the boot.

Glad I could sort it this way.

Thanks for all the help and suggestions.

I suggest this all the time to owners and they give up too easily. As along as you have the original valet key, it should open.

 

[pmcgsmurf]

Isn't there a second aux. battery for the SBC unit under the bonnet?

That is known as the auxiliary battery and will not power the boot lock if the main battery is disconnected.

I thought the aux battery was backup for the SBC ?

So disconnecting the main battery still leaves power to the SBC

I always unplug the SBC unit when I'm doing any work on the old W211 just to be sure.