Door Locks Cycle Rapidly Mercedes Benz ML320 ML430 ML500 ML350

Are your Mercedes Benz ML door locks moving up and down rapidly on your ML? This is also known as the Machine Gun Locks problem. This happens because the actuators in one of the doors is defective. The plastic tappet plate component inside the actuator has broken. You can try to replace the whole actuator or replace the broken part inside it. Watch the videos at the end of this article if you want to perform this repair. In the mean time you can disable the automatic locking and thus the annoying rapid locking/unlocking of the doors.

Estimated Repair Cost: $300-$400 performed by a Mechanic. If you Do-It-Yourself you are looking to spend under $200.

Parts: You can get them from these sellers for much less than the dealer.

Affected Models: W163 1998 – 2005 ML Class
ML-230 ML-270 CDi ML-320 ML-350 ML-400 CDi ML-430 ML-500 ML-55 AMG

Temporary Solution: Disable the auto lock feature on the ML. The ML is programmed to automatically lock the doors when you start driving. By disabling the automatic lock function, the car won’t try to automaticly lock the doors.
Do this:

  • Turn the key to position 2, all your cluster lights are on. Don’t start the car yet.
  • Now press down on the unlock button in the center console to lock the doors for at least 10 seconds and this will disable the auto lock feature.

Or watch this video to see how it is done.

The Problem: The actuators for the individual doors get damaged and jammed thus not responding to the motor when it tries to lock or unlcok the door. When using the keyfob or the dash button for locking or unlocking the doors, the jammed door actuator tries times to complete the lock/unlock action. Since the micro switch of the damaged door did not report a Locked /Unlock status to the All Activity Module (AAM), the AAM unlock and relock all the doors repeatedly until all the doors (micro switches) reported the Locked status.

Solution: Replace the door lock actuator, door locks will functioned normally again.

You can get the door lock actuator for a fraction of the dealer prices from Amazon see here.


1.) Determine which door has the broken actuator.

  • Manually unlock all the doors. Lock your doors. One of them will still be unlocked.
  • Manually lock all the doors. Now unlock them. One of them will still be locked.
  • If your doors work properly. Check the lift (trunk) gate.

2.) Using a flat screwdriver, remove the cover from the door handle. Once you do that you will see two Philips screws.

3.) Remove 2 bolts located inside your door handle

4.) Pull out the SRS Plastic Logo. Then unscrew the last bolt located under the SRS plastic logo.

5.) The door panel is held in place with push in pins. Pry off the door panel in place.

6.) Detach the light wire plug located underneath your lower door lamp

7.) Disconnect the other wires. One is the actual door lock the other goes to speaker.

8.) Roll up your window.

9.) Locate the hole at the edge of your door. It is covered by a rubber drain seal that prevents water from coming in the edge of your door, directly lined with your door handle from outside! Use Torx “T27” and unscrew the bolt directly leveled with the entrance cavity. Hint: You do not need unscrew it all the way. Just loosen the grip that is holding the plastic door handle cap outside.
10.) Now it is time to remove the door handle that is outside the car. Remove the plastic cap from your door handle.

11.) Carefully slide the rest of the door handle back. You will be pulling the door handle towards the back of the car.

12.) When you remove the door handle you will see 2 new bolts. Loose them but do not remove them.
13.) Remove the black plastic used as noise insulation. You simply peel this plastic off.
14.) Now remove your door latch. It has two torx bolts.

15.) Now it is time for you to pull the old actuator out and install the new one. This is the tricky part but you can do it. Once you install the new actuator make sure you didn’t bend the widnow guides. If you did make sure to set them to their proper position or your window will not go all the way day or go down slowly.

16.) Once you get the new actuator installed your are done with the hard part. Everything goes in in reverse order.