Alarm Cannot Be Activated or Deactivated

NOTE: If alarm is in activated mode and cannot be deactivated, but the car has to be moved for fault-tracing, the start inhibitor function must be disconnected.


Disconnecting Start Inhibitor Function (only if necessary)
Ignition off.
Remove alarm control module (position 210/211).





Bridge alarm relay plinth between position 5OE and position 5OF





Alternatively, use starter circuit P/N 3545333 which is installed in control module relay plinth position 210.
Start inhibitor function is then disabled. (Engine can be started.)





Sources Of Fault
Open-circuit in ground lead to alarm relay plinth.
Open-circuit in supply to alarm relay plinth.
Short-circuit to ground In supply to alarm relay plinth.
Open-circuit in ignition supply to alarm relay plinth.
Short-circuit to ground in ignition supply to alarm relay plinth.
Remote control programed incorrectly.
Fuse 2 faulty.
Fuse 6 faulty.
Remote control faulty.
Central locking relay faulty.
Relief relay 2/31 faulty.
Alarm control module faulty

For The Basic Alarm:
AT switch faulty.
Open-circuit in signal lead between central locking relay and alarm control module.
Short-circuit to ground in signal lead between central locking relay and alarm control module.
Short-circuit to supply in signal lead between central locking relay and alarm control module.

For The Guard Alarm I:
Open-circuit in accessory cable ground lead.
Short-circuit to ground in accessory cable supply.
Open-circuit in accessory cable supply.


NA. Basic Alarm Only
Fault-tracing starts with NA1.

NA1 Checking That Central Locking Is Working Using Remote Control

Ignition off.





NOTE: Try both remote controls.

Operate central locking using remote controls.
Central locking system should lock and unlock OK.





If reading is OK:
Check central locking system using door keys NA2.

If reading is incorrect:
See Fault-tracing in Central Locking Inoperable by Remote Control located in Power Lock testing and inspection.

NA2 Check Central Locking System Is Working Using Door Keys

Ignition off.
Operate central locking system using door key on driver's door.
Central locking system should lock and unlock OK.





If reading is OK:
Check fuse NA3.

If reading is incorrect:
Fault-trace in Central Locking System Completely Inoperable. Located in Power Locks.


NA3 Check Fuse

Ignition off.
Remove fuse 6 from fuse panel in engine compartment and check that fuse is intact.





If fuse is intact:
Check supply to fuse NA4.

If fuse is faulty:
Check lead between battery and alarm relay plinth position 30 (plinth 210) for short-circuit to ground as per WA4 See Other Fault-Tracing Test. Deal with fault and replace fuse.



NA4 Check Supply To Fuse

Ignition off.
Connect a voltmeter between fuseholder 11/6:1 and ground.
Voltmeter should read battery voltage.





If reading is OK:
Check ground lead NA5.

If reading is incorrect:
Check lead between battery and fuseholder 11/6:1 in fuse panel in engine compartment for open-circuit as per WA3 SEE Other Fault-Tracing Test.Deal with fault or replace lead.


Check Ground Lead

Ignition off.
Replace fuse 6 in fuse panel in engine compartment.





Remove alarm control module (position 210/211).





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





If reading is OK:
Check supply to alarm relay plinth NA6.

If reading is incorrect:
Check ground lead between alarm relay plinth position 31 (ground) and ground point 31/51 for open-circuit as per WA3 SEE Other Fault-Tracing Test.
Deal with fault or replace lead.


NA6 Check Supply To Alarm Relay Plinth

Ignition off.
Connect a voltmeter to alarm relay plinth between position 30 (plinth 210) and position 31 (ground).
Voltmeter should read battery voltage.





If reading is OK:
Check fuse NA7.

If reading is incorrect:
Check lead for supply between fuse 6 and alarm relay plinth position 30 (plinth 210) for open-circuit as per WA3 See Other Fault-Tracing Test. Deal with fault or replace lead.



NA7 Check Fuse

Ignition off.
Remove fuse 2 in fuse panel in engine compartment and check that fuse is intact.





If fuse is intact:
Check ignition supply NA8.

If fuse is faulty:
Check lead between ignition and alarm relay plinth position 15 for short-circuit to ground as per WA4 SEE Other Fault-Tracing Test. Deal with fault and replace fuse.


NA8 Check Ignition Supply

Test A:
Ignition off.
Replace fuse 2.





Connect a voltmeter to alarm relay plinth between position 15 and position 31 (ground). Voltmeter should read 0 V.





Test B:
Ignition on.
Reconnect voltmeter to alarm relay plinth between position 15 and position 31 (ground). Voltmeter should read battery voltage.





If both readings are OK:
Check that AT switch in driver's door lock unit is working NA9.

If either reading is incorrect:
Check lead between ignition and alarm relay plinth position 15 for open-circuit as per WA3 and short-circuit to ground as per WA4 See Other Fault-Tracing Test or try another relief relay 2/31. Deal with fault or replace lead.


NOTE: In some markets the locks cannot be operated using the door keys.


NA9 Checking That AT Switch In Driver's Door Lock Unit Is Working

Test A:
Ignition off.
Remove central locking relay (position 205/206).





Connect an ohmmeter to central locking system relay plinth between position AT and position 31 (ground). Ohmmeter should read very high resistance.

Test B:
Reconnect ohmmeter to central locking system relay plinth between position AT and position 31 (ground).





Turn door lock approx. 20° in one direction.
Then turn door lock 20° in other direction.
Ohmmeter should read approx. 0 ohm in both cases.





NOTE: AT switch grounding signal must occur before central locking system is operated, i.e. turning approx. 20° must give a grounding signal. This grounding signal must persist until central locking system is operated, which occurs at approx. 40° turn. In cars with deadlock position, the AT switch should be activated at 70° turn when locking.


If all readings are OK:
Check signal lead resistance NA10.

If any reading is Incorrect:
Check signal lead and ground lead to AT switch for open-circuit as per WA3 See Other Fault-Tracing Test or try another AT switch. Deal with fault or replace lead.


NA10 Check Signal Lead Resistance

Ignition off.
Connect an ohmmeter between alarm relay plinth position AL2 and central locking system relay plinth position AL2. Ohmmeter should read approx. 0 ohm.





If reading is OK:
Check signal lead resistance to ground NA11.

If reading is incorrect:
Check signal lead between alarm relay plinth position AL2 and central locking system relay plinth position AL2 for open-circuit as per WA3 See Other Fault-Tracing Test. Deal with fault or replace lead.


NA11 Check Signal Lead Resistance To Ground

Ignition off.
Connect an ohmmeter between alarm relay plinth position AL2 and central locking system relay plinth position 31 (ground). Ohmmeter should read infinite resistance.





If reading is OK:
Check signal lead supply NA12.

If reading is incorrect:
Check signal lead between alarm relay plinth position AL2 and central locking system relay plinth position AL2 for short-circuit to ground as per WA4 See Other Fault-Tracing Test. Deal with fault or replace lead.



NA12 Check Signal Lead Supply

Ignition off.
Connect a voltmeter between alarm relay plinth position AL2 and central locking system relay plinth position 31 (ground). Voltmeter should read 0 V.





If reading is OK:
Check activation signal from central locking relay NA13.

If reading is incorrect
Check signal lead between alarm relay plinth position AL2 and central locking system relay plinth position AL2 for short-circuit to supply as per WA5 See Other Fault-Tracing Test. Deal with fault or replace lead.



NA13 Check Activation Signal From Central Locking Relay

Ignition off.
Replace central locking relay (position 205/206).





Test A:
Deactivate alarm.





Connect a voltmeter to alarm relay plinth between position AL2 and position 31 (ground). Voltmeter should read less than 1 V.





Test B:
Activate alarm.





Reconnect voltmeter to alarm relay plinth between position AL2 and position 31 (ground). Voltmeter should read more than 4 V.





If reading is OK:
Try another alarm control module after Fault-Tracing In Alarm Wiring Harness in Guard Alarm I or II only

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

If any reading is incorrect:
Try another central locking relay.



NB. Guard Alarm I and II only

Fault-tracing starts with NB1.

NB1 Check Fuse
Deactivate alarm.





Ignition off.
Remove fuse 6 in fuse panel in engine compartment and check that fuse is intact.





If fuse is intact:
Check supply to fuse NB2.

If fuse is faulty:
Check lead between battery and alarm relay plinth position 30 (plinth 210) for short-circuit to ground as per WA4 See Other Fault-Tracing Test. Deal with fault and replace fuse.


NB2 Check Supply To Fuse

Ignition off.
Connect a voltmeter between fuseholder 11/6:1 and ground.
Voltmeter should read battery voltage.




If reading is OK:
Check ground lead NB3.

If reading is incorrect:
Check lead between battery and fuseholder 11/6:1 for open-circuit as per WA3 See Other Fault-Tracing Test. Deal with fault or replace lead.

NB3 Check Ground Lead

Ignition off
Replace fuse 6.





Remove alarm control module (position 210/211).





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





If reading is OK:
Check supply to alarm control module NB4.

If reading is incorrect:
Check ground lead between alarm relay plinth position 31 (ground) and ground point 31/51 for open-circuit as per WA3 See Other Fault-Tracing Test. Deal with fault or replace lead.


NB4 Check Supply To Alarm Control Module

Ignition off.
Connect a voltmeter to alarm relay plinth between position 30 (plinth 210) and position 31 (ground).
Voltmeter should read battery supply.





If reading is OK:
Check fuse NB5.

If reading is incorrect:
Check lead between fuseholder 11/2:1 and alarm relay plinth position 30 (plinth 210) for open-circuit as per WA3 See Other Fault-Tracing Test. Deal with fault or replace lead.


NB5 Check Fuse

Ignition off.
Remove fuse 2 in fuse panel in engine compartment and check that fuse is intact.





If fuse is intact:
Check ignition supply NB6.

If fuse is faulty:
Check lead between ignition and alarm relay plinth position 15 for short-circuit to ground as per WA4 See Other Fault-Tracing Test.
Deal with fault and replace fuse.


NB6 Check Ignition Supply

Test A:
Ignition off.
Replace fuse 2.





Connect a voltmeter to alarm relay plinth between position 15 and position 31 (ground). Voltmeter should read 0 V.





Test B:
Ignition on.
Reconnect voltmeter to alarm relay plinth between position 15 and position 31 (ground). Voltmeter should read battery voltage.





If both readings are OK:
Guard Alarm I:
Check status panel ground lead NB7.

Guard Alarm II:
Try another alarm control module after Fault-racing In Alarm Wiring Harness in Guard Alarm I or II only.
Run control module self-test in Guard Alarm II only before replacing control module.

If any reading is incorrect:
Check lead between ignition and alarm relay plinth position 15 for open-circuit as per WA3 and short-circuit to ground as per WA4 See Other Fault-Tracing Test or try another relief relay 2/31. Deal with fault or replace lead.



Guard Alarm I Only
NB7 Check Status Panel Ground Lead

Ignition off.
Replace alarm control module (position 210/211).
The 10-pin connector should be installed on top of control module.
Connector to status panel should be installed.





Connect an ohmmeter between yellow 4-pin connector position 4 (ground) and ground. Ohmmeter should read approx. 0 ohm.





If reading is OK:
Check status panel supply NB8.

If reading is incorrect:
Check lead between 10-pin connector position K1 and yellow 4-pin connector position 4 for open-circuit as per WA3 See Other Fault-Tracing Test.


NB8 Check Status Panel Supply

Ignition off.
Connect a voltmeter to yellow 4-pin connector between position 3 and position 4 (ground). Voltmeter should read battery voltage.





If reading is OK:
Try another alarm control module after fault-tracing.

If reading is incorrect:
Check lead between 10-pin connector position K4 and yellow 4-pin connector position 3 for open-circuit as per WA3 and short-circuit to ground as per WA4 See Other Fault-Tracing Test.