Checking the Bonnet Switch

Fault symptom
When activated, the alarm does not sound when the top is opened.

Diagnostic procedure
1 Connect the Intelligent Saab Tester (ISAT). Select the "OBTAIN READ-OUTS" menu and then "HOOD". Read the ISAT display,.
Hood open-> "OPEN"
Hood closed-> "CLOSED"
2 If it is not OK, connect the BOB and measure the resistance across pin 16 of the anti-theft alarm connector and a good grounding point.
Hood open-> < 1 ohm
Hood closed-> OL
If the resistance is OK, proceed to point 6.





3 Check the wiring for continuity/shorting by measuring the resistance across pin 16 of the anti-theft alarm connector and pin 1 of the top switch.
4 Also check the resistance across pin 2 of the top switch and the negative battery terminal.
The resistance measured in points 3 and 4 should be < 1 ohm.
5 Also check the voltage across pin 2 and the negative battery terminal. It should be 0 V.
6 If the resistance and voltage in points 4 and 5 are OK, the switch is probably at fault. Change the switch and check its operation.
7 If the fault persists after the above checks have been carried out, continue fault diagnosis as described in Before Control Module Replacement.