Occasionally when I start driving the Merc, usually at a very low speed, the doors lock by themselves as they do in our CR-V. Doesn't happen all the time, probably a little less than half. Is this an accessory feature that isn't working correctly? Looking at a Mercedes 80-010 function description of the door locking system for the 124, I don't see any kind of speed sensor in the locking system that would trigger the locks, so I'm guessing this is a problem rather than a feature.


Also still sorting out why my car doors sometimes lock by themselves when I shut them. I thought it was an issue with the driver's door but I distinctly heard the trunk lock click before all the others the last time it happened. Have to carry a spare key around in my wallet just in case I get out of the car while it's running and forget to lower the window!


This happens more in hot weather than cold and is not consistent--it can go a week without happening. I'm thinking it is probably related to my first question. Despite that problem, until this week, the system worked normally in all other respects and I could lock and unlock all doors with the key from the driver's side, passenger's side or trunk and lock and unlock with the driver's and passenger door knobs. Suddenly, however, I cannot press down on the driver's side knob to lock the car, nor can I use the key to lock it from that side. Unlocking is fine and the driver's door locks correctly when I use the trunk or passenger door lock. I'm going to have to take off the door panel to see if there is some sort of alignment issue or kink in the linkage that relates to the knob.


For the self locking problem, anything I should be looking at first? I'm thinking there may be some flukiness in the pneumatic control unit since all doors are affected.


Also, is the '95 E300D equipped with a remote keyless locking system? I saw a reference to synchronizing an infrared remote control transmitter while looking through the technical discussion of the locking system. I never got a transmitter when I bought the car so am unaware if the E300D was so equipped. Or was it part of the optional equipment?


Thanks for any info!

AFAIK, the '95 E300D does not have a factory remote lock unless one was available for a high-end W124 E-class (like the E/500/E) and it was added as an option or retrofitted by a subsequent owner. I added my own remote lock using one of the inexpensive modules available from various Internet sellers.

The doors should not lock on their own, either when you shut them or when the car reaches some road speed; perhaps your convenience module (under the rear seat, left side) is mis-behaving. Another possibility, someone else installed a remote lock and it is doing the locking.

Inability to normally operate the driver's door lock may be a problem with that lock mechanism and/or switch. There is an electrical switch as well as a pneumatic actuator, all interlinked.

Jeremy

__________________

"Buster" in the '95

Our all-Diesel family
1996 E300D (W210) . .338,000 miles Wife's car
2005 E320 CDI . . 113,000 miles My car
Santa Rosa population 176,762 (2022)
Total. . . . . . . . . . . . 627,762
"Oh lord won't you buy me a Mercedes Benz."
-- Janis Joplin, October 1, 1970