GLA-321

EA. DTC 321

Condition






Diagnostic trouble code (DTC) GLA-321 is stored if the control module registers that the siren control module transmits a signal that battery voltage to the siren drops below 6.0 V, when the siren is powered up or when the alarm is activated or deactivated.

Substitute value
None.

Possible source
Battery voltage too low due to insufficient charge or poor battery
Open-circuit or short-circuit to ground in siren communication cable.
Open-circuit in siren power supply or ground lead.

Fault symptom(s)
Indicator LED flashes for 15 seconds when the ignition is switched on.
When the alarm is activated the internal battery takes over power supply and the siren sounds for 30 seconds.

Start fault-tracing with EB.


EB1. Erasing Diagnostic Trouble Codes (DTCs)





Ignition on.
Erase diagnostic trouble codes (DTCs).

EB2. Reading Off Diagnostic Trouble Codes (DTCs)

Ignition on.
Wait at least 1 minute.
Ignition off, remove the key from the ignition switch and close all doors, the hood, trunk lid or tailgate.
Lock the car with the remote control.
Wait for approximately 10 seconds.
Unlock the car with the remote control.
Ignition on.
Read off diagnostic trouble codes (DTCs).
Did diagnostic trouble code (DTC) GLA-321 recur?
Yes: Go to EB3.
No: Go to EB8.


EB3. Checking Connectors





Ignition off.
Expose VGLA control module according to Alarm Module
Remove siren according to Alarm Horn Service and Repair
Check siren and VGLA control module connectors for contact resistance and oxidation according to WWA5 WW. Checking Wiring and Connections
Ignition on.
Erase diagnostic trouble codes (DTCs).


EB4. Reading Off Diagnostic Trouble Codess (DTCs)






Ignition on.
Wait at least 1 minute.
Ignition off, remove the key from the ignition switch and close all doors, the hood, trunk lid or tailgate.
Lock the car with the remote control.
Wait for approximately 10 seconds.
Unlock the car with the remote control.
Ignition on.
Read off diagnostic trouble codes (DTCs).
Did diagnostic trouble code (DTC) GLA-321 recur?
Yes: Go to EB5.
No: Fault corrected


EB5. Checking Cables






Ignition off.
Check fuse 6.

Hint: If the fuse is blown, check the circuit after fuse 6 for an open-circuit according to WWA2 WW. Checking Wiring and Connections

Check cable between control module #B15 and siren #5 for a short-circuit to ground according to WWA3, and for an open-circuit according to WWA2. Check cable between fuse 6 and siren #4 for an open-circuit according to WWA2 WW. Checking Wiring and Connections

Other Information:
The voltage between siren #4 and ground should be battery voltage.
Remedy as necessary. Then continue with EB6


EB6. Erasing Diagnostic Trouble Codes (DTCs)






Ignition on.
Erase diagnostic trouble codes (DTCs).


EB7. Verification

Hint: After carrying out the repair, check that the fault has been remedied as follows:

Reconnect connectors, reinstall components.
Remove key from ignition switch.
Ensure that all doors, the hood, trunk lid/tailgate are closed.
Lock the car with the remote control.
Wait approximately 10 seconds.
Unlock the car with the remote control.
Ignition on.
Read off diagnostic trouble codes (DTCs).
Does diagnostic trouble code (DTC) GLA-321 recur?
Yes: Fault not found
No: Fault corrected


EB8 Intermittent fault

Check cable between control module #B15 and siren #5 for an intermittent short-circuit to ground according to WWB3 and an intermittent open-circuit according to WWB2. Check cable between fuse 6 and siren #4 for an intermittent open-circuit according to WWB2 WW. Checking Wiring and Connections Operation done