Can anyone shed light on this problem with our 1999 ML320?
Normal operation of ML320 door locks: Door locks will self-lock when car
speed reaches about 5 MPH, and stay locked until manually unlocked. Alarm
system is armed when car is locked via remote-control, and alarm will be
activated if any door locked is unlocked from the inside (e.g., if someone
is inside the car when it is locked).
Just-occurring, "crazy" operation of door locks: Door locks will self-lock
as normal when speed reaches about 5 MPH, but soon thereafter, the driver
door lock autonomously un-locks. If car comes to a stop, then resumes
speed, all door locks will again self-lock (including the driver door lock),
but very soon thereafter the driver door lock autonomously un-locks. This
locking/unlocking repeats randomly as the car is being driven. When the car
is parked and locked, soon thereafter the driver door lock autonomously
un-locks, simultaneously triggering the alarm. If the car is left parked,
the driver door lock appears to randomly cycle through periods of
self-un-locking, then self-re-locking, each time setting off the alarm when
What's happening? There seems to be no fuse labeled as being specific for
the locking system, which might be an easy way to at least solve the
automatic alarm triggering problem. There seem to be at least two
door-lock-related relays -- could one of these be defective?
Is this a common problem with a 1999 ML320? Anyone experienced this, and
know the cause/fix?