Ptrigg17

I have done multiple searches looking for a reference to remove and replace the drivers side keyless go door handle. It was not working when I recently purchased my 07 550 cabriolet. The passenger door functions fine as does the start button and I have changed the batteries in the remote. I have read that this is a common failure item and that replacement is the cure however I have not been able to find any reference to "how to ". I would appreciate it if someone could point me in the direction of a previous post or give me a brief narrative. Thanks in advance.

abqhudson

I have the same problem.

Any help will be appreciated.

ambit

I've replaced mine about 3x.. let me go take some pics. Its 1 screw behind the black weather stripping, but putting it back together is a pain.

ambit

OK
Order new handle w/ keyless Go in correct color. Usually ~$180
Open driver-side door, pull back weather stripping near top of door.

The Torx screw you need is in the upper hole. I used a T-15 screwdriver.


Pry the key tumbler out from the outside of the car. Try not to scratch your paint.

Pull it free from the door. You can unplug the wire and set it aside.


Now getting the handle off is a little difficult. Pull it towards yourself like you were opening the door, and at the same time towards the rear of the car.
It should pop free and only be dangling by the 2 keyless go wires.

Putting the handle back in correctly is the hardest part. You need to catch the right side of the new handle behind the metal bar that mechanically unlocks the door. While holding the black rubber seal in place, and making sure the left side is seated correctly.
I usually get it wrong a few times. Pulling on the handle does not unlock the door if you don't get the right side in the correct place.
It usually takes me 10 mins to change it out.

Ptrigg17

That is really helpful, thanks so much , where do you buy the part ?

ambit

NOT from mymercedesparts.com
they sent me a broke one and wouldn't RMA it.

My last one was from
http://www.getmercedesparts.com Jan 2014
Item: body hardware, door, lock & hardware, handle, outside w/keyless, obsidian blk Left
Price: $177.60
Qty: 1

Make sure you get the correct side of your car

My P/N was
21176011709197

abqhudson

Thank you very much.

Ptrigg17

I decided to scope out the job before purchasing the part and I have the following questions.
There appears to be a sensor next to the key slot, is there a way to determine if the problem is with the handle or the sensor? I do not want to replace the handle and find it does not fix the problem.
When removing and replacing the Torx retaining screw, how do you prevent the screw from falling to the bottom of the door requiring removal of the door panel?

ambit

That little 2mm square sensor next to the key hole is for infrared. For example, if you push and hold the unlock button on your remote it will roll the windows down (doesn't always work). Doesn't have anything to do with the keyless go 'button' on the inside of the door handle.

The screw stays in there.. somehow.. its retained. I've taken mine apart at least 5x now and its never fallen down.

Ptrigg17

Thanks , now I feel comfortable proceeding.

Nahhas26

I'm working on a salvage project CLK550, it basically all done except for the new passenger door I bought doe's not have the keyless-go option and the car does. Based on this very helpful thread and some intuition, I'm assuming I need to switch the actuator out of the door with Keyless-Go and put it into the door without Keyless-Go to get the Keyless door handle to function? Is this correct and entirely correct? Or is there more to it? Any feedback would be greatly appreciated.

Rudeney

You need the door handle, door controller and antenna for the old door. I believe everything else is the same.

Nahhas26

What exactly is the door controller and antenna?

Rudeney

The door controller is a simple computer. It's a "black box" inside the door that controls all of its components. Your car uses a CAN bus so that instead of having pounds of wire running between all the devices int he car, they run wire to these computer than then talk over a pair of wires on a "bus" much like computers communicate over a wired network. For example, the seat control switches on the door don't have a dozen wires leading to the motors int he seat. They have a few inches of wire connecting them to the door controller, which in turn sends signals over the CAN bus that seat controller recognizes and then activates its motors accordingly.

With KeylessGo, you have an antenna in the door that communicates wirelessly with the key. It's connected to the door controller which in turn communicates with the other systems that authorize locking and unlocking. Cars without KeylessGO will have a different door controller and lack the antenna. Also, the door handle on KeylessGo cars have a touch-sensitive panel and the lock button, plus wiring to connect those to the door controller.

Nahhas26

Thanks a bunch for that clarification. Now would switching out the door lock actuators be useless? I already went through the trouble of taking out the actuator of the new door, I sure hope this was not a wasted effort . I thought what I had to do was switch the actuator and the exterior door handle because the KeylessGo handle comes with and extra wire, as opposed to the non-KG handle, that plugs into the extra wire on the KG enabled actuator.

Rudeney

I'd have to look at the parts diagram, but I assumed the KG handle would plug into the door controller, not the lock actuator. But I guess it's possible they piggy-backed that circuit to save some wiring. By all means, if the old handle plugged into the lock actuator, swap that out, too.

Nahhas26

To think removing the actuator out of the CLK door without KeylessGo was a nightmare only to realize how impossible getting the actuator with KeylessGo out makes me want to switch my method of transportation to bicycle.

The KG enabled actuator is the same as any other w209 actuator except it has one extra wire and a black box, which I believe is the antenna, attached to it.

I removed the rubber plug under the door and removed the nut on the window support bar but it barley gives me any wiggle room. How do you actually get that bolt out to free up the window track? Hitting it with a hammer didn't even make it budge. I will attach some pictures showing what I'm talking about.



Removed drain plug and removed nut






Top of bolt that wont move






This is off topic but what is this black rectangular unit? It is not on the non KG door

Rudeney

That black rectangle is the KG antenna.

Nahhas26

Any idea how to disassemble the window rail?

Rudeney

You have to drill out the rivets.

Nahhas26

It was quite the job but I ended up take out the window and window support which then made taking out the actuator a piece of cake. That bottom bolt I referred to does not, or at least did not, come out. Taking out the glass didn't only make switching the actuators easier but I also was able to switch glass from the old door that was tinted. That rectangular antenna comes out by undoing the 2 screws that are hidden behind the exterior molding. The controller was an easy swap. It's unbelievable how much wiring is in these doors especially with the KG. I redid the wiring for a 2012 Lincoln MKX with the same door handle lock-unlock feature and it wasn't half as complex as this, yet this seemed less nerve wrecking. Probably because everything has one place in a Mercedes; there's no guessing where plugs and screws go, however there is a lot of them

eddieo45

this job is WAY out of my comfort range so let me just ask this: does it make sense that my keyless LOCK button works (sometimes) while the keyless UNLOCK sensor pretty much never does?

Nahhas26

Mine seems to do the same thing. I've even had both buttons on the driver's door handle only lock the car, which still happens sometimes and it still confuses me. I've only got my keyless convertible top operation to work a couple times since owning the car, and even then the process gets interrupted once or twice.

eddieo45

great writeup ambit! I will say one other hard part was getting the new handle plugged in on the left. I don't know if I inadvertently broke something that would have held the other end in place but I had to pull it up through the hole with hemostats while plugging it in. Your tip about the metal bar inspired me to cheat a little with a bent rod through the original bolt hole to nudge it closer.

Rovel

I hope somebody can help me here. I was switching driver side door handle. Put the new one in and then realized that the keyless go wire was getting on the way of the glass. I tried reinstalling the door handle multiple times with no success. Eventually some plastic that looks like a retainer for the keyless go connection came loose How do I fix it? Should I take the door panel off? If I should remove the door panel, how will I glue that black foam thing back on the door?