Engine hood switch
Symptom: The alarm does not sound when the hood is opened and the alarm is armed.
Fault symptom
The alarm does not sound when the hood is opened and the alarm is armed.
Diagnostic procedure
1 Check the operation of open/close bonnet
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Connect the ISAT scan tool.
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Open/close the bonnet, observing the ISAT scan tool display at the same time.
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The ISAT scan tool should display "OPEN" and "CLOSED" respectively.
Is ISAT indicating open/close bonnet correctly?
The fault is of intermittent nature, proceed to point 5.
Continue with point 2.
2 Check the current, bonnet open/closed
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Unplug the connector from the bonnet switch.
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Turn the ignition switch to the "ON" (+15) position.
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Repeat the ISAT scan tool commands as in point 1.
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When the connector is open, the ISAT scan tool should display "OPEN". Connect a lead between pin 1 of the connector and a good grounding point. The ISAT scan tool should display "CLOSED".
Is the function correct?
Continue with point 3.
Continue with point 4.
3 Check the bonnet switch
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Connect jumper lead between the two connector pins.
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The ISAT scan tool should display "CLOSED".
Is ISAT indicating "CLOSED"?
Change the bonnet switch.
Check for continuity, and take remedial action if necessary, between pin 2 of the bonnet switch and grounding point G33S.
4 Check the wiring connected to connector H33-3
Check the wiring harness for continuity between pin 28 of connector H33-3 and pin 1 of the bonnet switch.
The resistance should be < 1 ohm.
Is the resistance correct?
Continue with point 6.
Repair or replace the wiring harness.
5 Check the wiring connected to the electronic control module
Check the wiring harness for continuity between pin 28 of connector H33-3 and pin 16 of the anti-theft alarm's electronic control module.
The resistance should be < 1 ohm.
Is the resistance correct?
Continue with point 5.
Repair or replace the wiring harness.
6 Final check
Check to see if the fault symptom remains.
Is the problem still present?
See "Before replacing a control module".
The remedial measures taken were correct or the fault is of intermittent nature.
