GLA-312

DA. DTC 312

Condition





Diagnostic trouble code (DTC) GLA-312 is stored after 2 seconds if the control module registers that the voltage in the internal siren battery is 2.5 V when the alarm system is powered up or when the alarm is activated or deactivated.

Substitute Value
None.

Possible Source
Defective internal battery.
Fault in 15 I-supply to the siren.
Defective siren.

Fault Symptom(s)
The indicator LED flashes for 15 seconds when the ignition is switched on.

DB1. Erasing Diagnostic Trouble Codes (DTCs)





Ignition for 30 seconds.
Erase diagnostic trouble codes (DTCs).

DB2. Reading Off Diagnostic Trouble Codes (DTCs)

Ignition on.
Wait for 30 seconds.
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 30 seconds.
Unlock the car with the remote control.
Ignition on.
Read off diagnostic trouble codes (DTCs).
Did diagnostic trouble code (DTC) GLA-312 recur?
Yes: Go to DB3.
No: Go to DB9.

DB3. Checking Cables





Expose VGLA control module according Alarm Module
Disconnect siren according to Alarm Horn Service and Repair
Disconnect siren connector.
Ignition on. Check fuse 29.

Check cable between 15-I rail #4 in the relay box and siren connector #1 for an open-circuit according to WWA2 and a short-circuit to ground according to WWA3. Check siren and control module connectors for contact resistance and oxidation according to WWA5. WW. Checking Wiring and Connections

Other Information:
The voltage between siren connector #1 and ground should be battery voltage when the ignition is on. Remedy as necessary. Was a fault detected?
Yes: Go to DB7.
No: Go to DB4.

DB4. Replacing Component





Ignition off.
Siren removed.
Try a new battery.
Ignition on.
Erase diagnostic trouble codes (DTCs).

DB5. 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-312 recur?
Yes: Go to DB6.
No: Fault corrected

DB6. Replacing Component

Try a new siren according to Replacing Siren in Alarm Horn.

DB7 Erasing Diagnostic Trouble Codes (DTCs)





Ignition on.
Erase diagnostic trouble codes (DTCs).

DB8 Verification





Hint: Afier repairs have been completed they must be verified as follows to ensure that the fault has been eliminated:

Ignition on.
Wait for approximately 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 approximately 10 seconds.
Unlock the car with the remote control.
Read off diagnostic trouble codes (DTCs).
Does diagnostic trouble code (DTC) GLA-321 recur?
Yes: Fault not found
No: Fault corrected

DB9 Intermittent Fault

Check siren and VGLA control module connectors for loose connections according to WWB5 and contact resistance and oxidation according to WWB6 WW. Checking Wiring and Connections Operation done