postoak

About once a week my C240's other 3 doors won't auto-unlock when I open the driver's door. I've taken this in twice and the "controller" was replaced both times -- with no change.

I've done searches and seen other people reporting this same problem but no one ever posted a solution. Has anyone had this problem and gotten it fixed? What was the answer?

mleskovar

...on how you unlock the car with the remote. If you click once and unlock just the driver's door then when you leave the car only the driver's door will unlock. Click twice to unlock all doors and all doors will unlock when you leave. A very subtle safety feature that you would appreciate if you felt compromised by having all doors unlocked when you enter or leave your car.

postoak

Thanks for the response, but I mean that when I'm inside the car and open the driver's door to exit, the other 3 doors don't unlock. This, too, may have been a setting, but it's obviously not something I'm changing.

mleskovar

Correct. Whether or not the other doors open when you leave through the driver's door is determined by how you entered the car. If you entered it using a double click (open all doors), then after you reach your destination when you open the driver's door to leave the other three doors will open. If you entered the car with a single click (open only driver's door) then after you reach your destination and open the driver's door to leave the other doors will remain locked.

postoak

Hmm, but I've got my doors programmed to open with a single click.

mleskovar

Don't know how that affects it....try it and see. You have to use remote to unlock car, drive until auto lock feature engages (9mph), turn off/remove key, open driver's door and see. Try it with one and two clicks entering and see if there's a difference and let us know. Kind of defeats the purpose of the global feature if it works that way.

postoak

I tried 1 and 2 clicks and the locks worked afterward. Still, this is the best lead yet and I'll pay close attention to what buttons I've pressed before entering the car. I admit to fingering the remote in my pocket and sometimes incorrectly pressing lock or trunk unlock before hitting the unlock button.

postoak

Happened again today, even though I *know* I pushed the correct buttons on the remote in unlocking the car from the outside. (Just to make it clear, though, the problem happens later, when I'm exiting the car by opening the driver's door.)

mleskovar

Buttons? You only need to push one...twice. At this point...RTFM and if it doesn't work to your satisfaction make a service visit.

postoak

By "buttons", instead of "button", I meant I've been very careful to only push the "unlock" to enter the car and "lock" when leaving it. Before, I would work the control in my pocket and sometimes hit an incorrect button before finding the correct one. I've read the manual a number of times, but since I've had the car in twice for this, I would think the service guy would have pointed it out to me if I was just doing something wrong.

postoak

Well, I haven't had this happen in a month. Long story short, as to what I did to prevent it happening is to swap keys every day. Perhaps someone here can explain why that would work.

When I first switch to a new key, I go 15 days before it happens again -- then it begins to happen more and more frequently. Swap to the other key and the cycle repeats. Some setting is being lost -- either in the keys or, more probably, wherever settings are stored in the car itself. Why changing keys prevents this from happening, I'd be interested to learn.

The dealer hasn't a clue.

Hightower

Try pushing and holding the lock and unlock buttons for 10 seconds whilst having it pointed at the rear view mirror, this will then change for 1 door open or all doors open each time u do this.

Jayhawk

This may just complicate things, but the e-keys on my S-class can be programmed (by pushing and holding the lock and unlock buttons) to unlock all doors or just the drivers door. The doors will operate the same way on exiting. These keys come w/ two or three settings for locking ans unlocking the doors. Your dealer should be able to explain exactly how yours operate.

Have you checked the batteries in the keys?

postoak

Thanks, I'm aware that setting is changed via the key. Reading that in the manual is what turned my attention to the keys as the possible source of problems.

Both keys have had this problem since day one, so I doubt it's the batteries, but I'll bring this to the dealer's attention the next time I'm in for service.

Jayhawk

Please let us know what you learn.