Glass Breakage Sensor

Fault symptom
The glass breakage sensor does not trigger the alarm.







Diagnostic procedure
1 Check the operation of the glass breakage sensor
- Connect an Intelligent Saab Tester (ISAT) scan tool.
- Select "READ VALUES".
- Select "GLASS BREAK SENSOR".
- Jingle a bunch of keys or the like near the sensor.

The ISAT scan tool display should show a reading of between 0 and 255.
Does it display a correct reading?
[YES] Continue with points.
[NO] If the reading is not OK or unchanged, continue with point 2.







2 Check the operation of the glass breakage sensor
- Disconnect the glass breakage sensor by unplugging the 4-pin connector.
- Select "READ VALUES".
- Select "GLASS BREAK SENSOR".

If the connector is still unplugged, the ISAT scan tool should show "0".
Connect a jumper lead between pins 2 and 4 of the connector and the ISAT scan tool should show 255.
Does it show a correct reading?
[YES] Continue with point 4.
[NO] Continue with point 3.







3 Check the wiring
Check the wiring harness for continuity between:
- connector, pin 2, and alarm control module, pin 7.
- connector, pin 4, and alarm control module, pin 5.

The resistance should be < 1 ohm.
Is the resistance OK?
[YES] Continue with point 5.
[NO] Repair or replace the wiring harness.

4 Check the glass breakage sensor
Carry out a visual inspection of the sensor and connector. If nothing is found that can be rectified, change the glass breakage sensor.

5 Final test
- Disconnect the ISAT scan tool.
- Close all doors.
- Arm the alarm and wait until the LED flashes at the rate of 1 flash every 2 seconds.
- Jingle a bunch of keys close to the sensor.

The alarm should go off.
Did the alarm go off?
[YES] The remedial measure taken was correct or the fault is of intermittent nature.
[NO] Continue as described in "Before Changing the Electronic Control Module". Before Changing the Electronic Control Module