F430 door does not lock, larm goes off

Was this part of your diagnosis for the current issue or did this only happen after you were playing with the door handles?

If the door is not closing/latching properly, it may interfere with the locking process (i.e. the movement of the lock actuator). If the actuator can't move to the correct position (triggering "locked" and "latched" microswitches), then the Window ECU & Door ECU unlock the doors.

More than you probably need to know, but the Window and Door ECUs operate in tandem to drive the electric motor in the lock/latch assembly (see below)

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The motor gearing moves the end of the big metal pivot/fulcrum up and down. The position of the components are detected by the two microswitches on the left. Anyway, if the relationship between the fulcrum and that metal post directly underneath are in the wrong positions in relation to each other, the microswitches may not be triggered and the Window ECU rejects the locking command.

A shot without the metal pivot/fulcrum:

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When you unlock the door with the fob, the Alarm ECU talks to the Window ECU which talks to the Door ECU which activates the lock motor.

At this point, I'm not sure what's going on.

 

So are you saying the fault was there before or after?

 

The "unlatched" microswitch in the latch/lock mechanism in the photos operate the following:

The warning light on the instrument panel (door open)
The F1 pump (driver's side only)
The window drop (2cm)
The interior light

There is also an input into the Alarm ECU.

Are you getting any of these when your alarm goes off?

The interior door handle can also trigger the "unlatched" microswitch by causing the door to unlatch (via the cable). The door handles do have other microswitches for other functions (locking and unlocking).

 

Yes, quite bizarre.

It's like the unlocked (unlockable) doors are keeping the alarm active. Then, perhaps, the alarm is triggered by motion.

The inner door handle/s may be falsely sending a signal to the Window ECU to unlock the doors. i.e. the microswitch activated by lifting the handle, not the small locking lever. You could disconnect that particular microswitch on one door and see what happens. Are the electrical cables long enough to access the plugs without pulling the door card off?

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Maybe you could also cycle the exterior doorlocks with your keys to see if anything changes? Can you lock the doors with the keys or do the doorlocks reopen immediately?

 

Silly question..did you check / change key fob battery

 

I occasionally get the same issue and have tracked it down to a microswitch in the exterior door handle. I have had a few issues with window drop, doors not locking, window switches staying illuminated and they have all been related to microswitch misalignment.

 

Strange. As far as I can see, the switch on the exterior door handle only affects the window drop (you can't unlock the door using the exterior handle, unlike the interior door handle). I can't see an input into the Alarm system. Of course, if you manually operate the door handle, that will activate the latch switches. The latch switches input into the Alarm ECU.

Can you lock the doors on a 430 with the windows down?

 

I assumed by this that you meant the interior door handles? Did you touch the interior and exterior door handles?