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 10 and 255.
Does It display a correct reading?
[YES] Proceed to point 6.
[NO] 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".
It the connector remains open, the ISAT scan tool display should show "0".
Connect a jumper lead between pins 1 and 2 of the connector. The scan tool display should now show a reading of 255.
Does the display show a correct reading?
[YES] Change the glass breakage sensor.
[NO] Continue with point 3.






3 Check the operation of the electronic control module
- Unplug connector H10-4.
- Select "READ VALUES".
- Select "GLASS BREAK SENSOR".
With the connector open, the ISAT scan tool display should show "0".
With a jumper lead connected between pins 2 and 3 of connector H10-4, the scan tool display should show a reading of 255.
Does the display show a correct reading?
[YES] Proceed to point 5.
[NO] Continue with point 4.

4 Check the wiring connected to the electronic control module
Check the wiring harness for continuity between:
- connector H10-4 (pin 2) and the electronic control module (pin 7)
- connector H10-4 (pin 3) and the electronic control module (pin 5).
The resistance should be < 1 ohm.
Is the resistance OK?
[YES] Proceed to point 6.
[NO] Repair or replace the wiring harness.







5 Check the wiring connected to the glass breakage sensor
Check the wiring harness for continuity between:
- connector H10-4 (pin 2) and the glass breakage sensor (pin 1)
- connector H10-4 (pin 3) and the glass breakage sensor (pin 2).
The resistance should be < 1 ohm.
Is the resistance OK?
[YES] Carry out a visual inspection of the sensor and connector.
[NO] Repair or replace the wiring harness.
If nothing can be found that can be corrected, change the glass breakage sensor.

6 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.
Is the alarm triggered?
[YES] The remedial measures taken were correct or the fault is of intermittent nature.
[NO] Continue as described in "Before Changing The Electronic Control Module".