what are solenoid switches used for?

88-91 Toyota Camry & Clifford Intelliguard 770 install. (see this wiring diagram) The door key locks have switches that activate the lock/unlock solenoids when the key is turned. This I understand. But the solenoids also have switches incorporated which serve some purpose, but I don't know what. What is the purpose of the solenoid switches? If I lift the lock button, this doesn't automatically unlock all doors. Does this simply indicate to the controller that the door is locked so it does not lock the doors it's already locked? But these switches are not used in the rear doors which kind of shoots this theory; wouldn't the controller need to know the status of all door locks? What do these switches do? Thanks,

Using the key, if you unlock the drivers door twice, does it unlock the other doors?  Does the vehicle have a factory alarm system?  If so, these switches arm and disarm the OEM alarm.

No "progressive" unlocking. No factory alarm was available on this car.

A microswitch setting on the end physically incorporated into it that triggers the door locking relays. Effectively these are the lock and unlock wires type A and B you will find on most vehicles. A master with microswitch is also known as a five wire and a slave (no microswitch) is also known as a 2 wire. Most front doors have 5 wires so via the relay you can unlock all doors. Lifting the lock button in the circumstances means that the lock button isn't connected to the switch wires. Do that in say a Nissan Maxima or a BMW and it will lock or unlock the car, it just depends on the vehicle manufacturer.

Sounds logical, except for one thing: in the front doors these solenoid switches are connected. They do not unlock the car if the lock button is lifted. see this wiring diagram So, they must have a different purpose... jj

No they won't lock but will unlock if the key is in the ignition or the door is open, safety interlocks, but why are you asking, this is a bit like auto electrics theory at your local college rather than real world questions.