Hood Switch

Fault symptom
The alarm does not sound when the bonnet is opened with the alarm armed.







Diagnostic procedure
1 Check the operation of the bonnet switch
- Connect an Intelligent Saab Tester (ISAT) scan tool.
- Select "READ VALUES".
- Select "BONNET".
- Open and close the bonnet, observing the ISAT scan tool display at the same time.

The ISAT scan tool display should read OPEN" and "CLOSED" as appropriate.
Does it display the correct readings?
[YES] The fault is of intermittent nature, proceed to point 5.
[NO] Continue with point 2.







2 Check the current, bonnet open and closed
- Unplug the connector from the bonnet switch.
- ignition switch "ON" (+15).
- Select "BONNET" with the ISAT scan tool.

When the connector is unplugged, the ISAT scan tool should display "OPEN".
Connect a jumper lead between the relevant connector pin and a good grounding point.
The ISAT scan tool should display "CLOSED".
Does it display "CLOSED"?
[YES] Continue with point 3.
[NO] Continue with point 4.

3 Check the bonnet switch
- Select "BONNET".
- Connect jumper lead between the two connector pins.

The ISAT scan tool should display "CLOSED".
Does the ISAT scan tool display "CLOSED"?
[YES] Change the bonnet switch.
[NO] Check for continuity, and take remedial action if necessary, between pin 2 of the bonnet switch and grounding point G30.







4 Check the wiring
Check the wiring harness for continuity between pin I of the bonnet switch connector and pin 16 of the anti-theft alarm's control module.

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

5 Final test
Check to see if the fault symptom persists.

Does the trouble persist?
[YES] Continue as described in "Before Changing the Electronic Control Module". Before Changing the Electronic Control Module
[NO] The remedial measure taken was correct or the fault is of intermittent nature.