900 SE Hatchback L4-1985cc 2.0L DOHC Turbo EFI (1997)
Door Sensor/Switch (For Alarm): Description and Operation
Door and luggage compartment switches The switches (for interior lighting) are included in the theft alarm as sensors for doors and tailgate. The
switches are mounted in the body, in the middle of each door and the tailgate. All door switches are connected to the alarm control module (pin 4) via the
car's Integrated Central Electronics (ICE) control module. The luggage compartment switch is connected directly via the car wiring harness to pin 3 on
the alarm control module. The control module then senses if a door is opened when the alarm is armed by monitoring the voltage over the switch as
follows:
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When the door/tailgate is closed, the voltage between the switch and ground should be +12 V.
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The switch is grounded when the door/tailgate is opened. The voltage between the switch and ground is then 0 V. The alarm is set off.
The electronic control module senses via pin, 18 whether the driver's door is open or not and if it is prevents the alarm from being armed.
