DTC B2A07: Backup Battery Charge System Performance

Diagnosis start condition :

When ignition switch is ON.

DTC detecting condition :

Backup battery is disconnected for at least 5 seconds when the ignition switch is turned ON. (Detached backup battery connection, etc.)

Trouble symptom :

ACN/SOS function cannot be used when the main battery is disconnected.
RED LED illuminates.

Failure detection pattern :

"Primary" (high-priority diagnosis)

Warning light/indicator light :

Both ON -
GREEN LED ON -
GREEN LED blinks -
RED LED ONO
RED LED blinks -
Both OFF -

CAUTION:

After the DCM is replaced, registrations of CommCheck and immobilizer system are required. Ref. to ENTERTAINMENT & MONITORING>TELEMATICS SYSTEM>OPERATION>REGISTRATION (COMM CHECK) .
Before performing diagnosis, refer to "CAUTION" in "General Description". Ref. to TELEMATICS SYSTEM (DIAGNOSTICS)>GENERAL DESCRIPTION>CAUTION .

CHECK DTC .
1. Charge the backup battery for 30 minutes to one hour with the ignition switch ON or during engine idling.
2. Read the DTC of [Telematics] using the Subaru Select Monitor. Ref. to TELEMATICS SYSTEM (DIAGNOSTICS)>DIAGNOSTIC TROUBLE CODE (DTC) .
Is DTC B2A07 displayed? (Current code)

Yes : GO TO 2.

No : Currently operating normally.

NOTE: In this case, natural discharging may be the cause of fault.
CHECK THE BACKUP BATTERY UNIT .
1. Turn the ignition switch to OFF.
2. Remove the DCM. Ref. to ENTERTAINMENT & MONITORING>DATA COMMUNICATION MODULE .
3. Remove the backup battery cover.
4. Disconnect the backup battery connector.
5. Measure the backup battery voltage.
Is the voltage 2.0 V or more?

Yes : Replace the DCM. Ref. to ENTERTAINMENT & MONITORING>DATA COMMUNICATION MODULE .

No : Replace the backup battery. Ref. to ENTERTAINMENT & MONITORING>DATA COMMUNICATION MODULE .

When the fault is not removed, replace the DCM. Ref. to ENTERTAINMENT & MONITORING>DATA COMMUNICATION MODULE .