No Alarm on Hood Bonnet

Guard Alarm I:
Check programing of control module to see that FUNCTIONS 6 and 8 are not set to SIGNAL PATTERN 1 (no output signal).

Sources of fault
Open-circuit in hood (bonnet) contact ground lead.
Open-circuit in signal lead between hood (bonnet) contact and alarm control module.
Short-circuit to supply in signal lead between hood (bonnet) contact and alarm control module.
Fault in hood (bonnet) contact.
Fault in alarm control module.

Fault-tracing starts at C1.

C1 Checking Ground Lead

Deactivate alarm.





Ignition off.





Open hood (bonnet)





Undo hood (bonnet) lock 2-pin connector.
Connect an ohmmeter between connector position 2 (ground) and ground. Ohmmeter should read approx. 0 Ohm.





If reading is OK:
Check signal lead supply C2.

If reading is incorrect:
Check lead between hood (bonnet) contact position 2 and ground point 31/44, or 1/1-, for open-circuit as per WA3 Other Fault-Tracing
Deal with fault or replace lead.


C2 Checking Signal Lead Supply
Ignition off.
Remove alarm control module (position 210/211).






Connect a voltmeter to alarm relay plinth between position FH and position 31 (ground). Voltmeter should read 0 V.





If reading is OK:
Check signal lead resistance C3.

If reading is incorrect:
Check lead between hood (bonnet) contact position 1 and alarm relay plinth position FH for short-circuit to supply as per WA5 Other Fault-Tracing Deal with fault or replace lead.



C3 Checking Signal Lead Resistance

Ignition off





Bridge hood (bonnet) contacts position 1 and position 2.





Connect an ohmmeter to alarm relay plinth between position FH and position 31 (ground). Ohmmeter should read approx. 0 ohm.





If reading is OK:
Checking hood (bonnet) contact C4.

If reading is incorrect:
Check lead between hood (bonnet) contact position 1 and alarm relay plinth position FH for open-circuit as per WA3 (See Other Fault-Tracing). Deal with fault or replace lead.


C4 Checking Hood (bonnet) Contact

Test A:
Ignition off.





Remove bridge between hood (bonnet) contact position 1 and position 2. Replace hood (bonnet) lock 2-pin connector.





Close hood (bonnet).





Connect an ohmmeter to alarm relay plinth between position FH and position 31 (ground). Ohmmeter should read infinite resistance when hood (bonnet) is closed.





Test B:
Ignition off.





Open hood (bonnet).





Reconnect ohmmeter to alarm relay plinth between position FH and position 31 (ground). Ohmmeter should read approx. 0 ohm when hood (bonnet) is open.





If readings are OK:
Try another alarm control module after fault-tracing.

Guard Alarm II:
Run control module self-test in Guard Alarm II (only) before replacing control module.

If any reading is incorrect:
Try another hood (bonnet) lock.