MB Alarm system + key

[uumode]

Supposing the remote key fob died or battery conked out when you were returning to your car parked 50 miles from home and the alarm is armed.

There is no small disable key as with aftermarket alarms to insert directly into the alarm in the engine bay. (of course you can't avoid deafening your ears when you open the bonnet to disengage the device!..but that's another story)

With the MB alarm there appears to be no method for disabling the alarm.
So even if you slide the mechanical key out of the alarm fob and open the door manually, you can't disable the wailing alarm + immobiliser, nor insert the mechanical key into the 'keyless' ignition

So what is the point of providing the mechanical key to open the door when

A. the alarm can't be disabled and
B. there is no provision for the mechanical key in the ignition process

 

[Anders]

So what is the point of providing the mechanical key to open the door when

A. the alarm can't be disabled and
B. there is no provision for the mechanical key in the ignition process

To lock the glove compartment with...

 

[Steve_Perry]

Are you referring to Keyless Go? Or the standard remote key fob with mechanical slide out key?

If it's the latter, you use the mechanical key to get into the vehicle and as you state the alarm is activated but once you insert the remote key fob into the ignition the alarm should be deactivated. The transponder in the remote keyfob does not use battery power to deactivate the steering lock.

Should be in the handbook.

S.

 

[sym]

As Steve Says.

My car came with an "emergency key" - which has no battery - a wafer thin version of the standard keyfob - has a metal sliding key in it, and the rest is inserted into the ignition (it does go !) just like the normal keyfob. It has a very thin infra red transponder unit in it, which is obviously powered from the ignition barrel, and de-activates the immobiliser & alarm, allowing you to start the car.

S.

 

[uumode]

Ah..... makes sense now.

I wrongly assumed the transponder needed battery power, and didn't realise that by inserting it into the ignition it would disable the alarm.

The wafer thin key also works
(just ran out into the garage to test it)

However I did find the mechanical slide out key doesn't operate the central locking. Only the door you insert it into.

 

[Brian WH]

Ah..... makes sense now.


However I did find the mechanical slide out key doesn't operate the central locking. Only the door you insert it into.

It is not supposed to as it is an emergency key. Also useful when you are on a ferry, you don't set the alarm but can lock the drivers door and the boot using the key.

 

[C240Sport97]

or you can switch off the tilt sensor .. at least you can on W202s!!

It is not supposed to as it is an emergency key. Also useful when you are on a ferry, you don't set the alarm but can lock the drivers door and the boot using the hey.

 

[uumode]

or you can switch off the tilt sensor .. at least you can on W202s!!

and you can open the boot only - remotely ,
and program the remote to open driver door only
... MB still have these 3 features on new E class...presumably

 

[Steve_Perry]

and you can open the boot only - remotely ,
and program the remote to open driver door only
... MB still have these 3 features on new E class...presumably

I presume you have found the open/close all windows and sunroof feature too? Point the remote at either the driver's door or passenger door... press and hold the unlock button to open everything, or press and hold the lock button to close everything.

S.

 

[uumode]

I presume you have found the open/close all windows and sunroof feature too? Point the remote at either the driver's door or passenger door... press and hold the unlock button to open everything, or press and hold the lock button to close everything.

S.

Of course

What I didn't anticipate with the slide out mechanical key is when unlocking an unarmed car, after a few mins the door automatically locked itself! I hope I haven't inadvertently primed an autolock feature.... Not much fun when your keys are in the cabin and you are outside.

 

[jimmy]

Of course

What I didn't anticipate with the slide out mechanical key is when unlocking an unarmed car, after a few mins the door automatically locked itself! I hope I haven't inadvertently primed an autolock feature.... Not much fun when your keys are in the cabin and you are outside.

This happens with the remote locking too, has worked on most cars I have owned. The doors re-lock after a few minutes only if a door has not been opened. The doors will not re-lock on their own if you have opened a door, so you cannot inadvertently lock your keys inside.

 

[uumode]

This happens with the remote locking too, has worked on most cars I have owned. The doors re-lock after a few minutes only if a door has not been opened. The doors will not re-lock on their own if you have opened a door, so you cannot inadvertently lock your keys inside.

PHEW!!!

That's good to know

 

[splang]

does the holding down unlock work on the w203 also ? to open all windows/close all windows?

Steve

 

[zygote]

does the holding down unlock work on the w203 also ? to open all windows/close all windows?

Steve

Sure does. Bugs me that Mercedes use IR to control this so you have to point the key at the door. Other manufacturers manage to do the same with RF, makes the Merc system look inferior.

 

[Shude]

Other manufacturers manage to do the same with RF, makes the Merc system look inferior.

Yeah, but at least they know you're looking at the car when the windows and sunroof are closing, so a child doesn't have a limb chopped off by them or something!

 

[uumode]

Yeah, but at least they know you're looking at the car when the windows and sunroof are closing, so a child doesn't have a limb chopped off by them or something!

The boot does a pretty neat chin upper cut too, if you're not careful

 

[Brian WH]

The boot does a pretty neat chin upper cut too, if you're not careful

Very useful for loiterers in the local carpark.

Seriously though, it's good show off factor when you approach with a full shopping trolley in the Supermarket carpark.

 

[adam1]

I tried to open boot with remote key but doesn't work. Is it available on later models only. My is Q4 02

 

[uumode]

I tried to open boot with remote key but doesn't work. Is it available on later models only. My is Q4 02

There should be a button on your remote fob, an icon of a bootlid opening, which is adjacent to the unlock button.

mine has 3 buttons, lock, unlock and boot opening
(could be the opening spring on the boot is gone?)

 

[mr. shr]

don't forget there's a delay on the opening. You have to press and hold the button for about three seconds before the boot opens.