DTC B2A0F: Backup Battery Degradation

Diagnosis start condition:

When ignition switch is ON.

DTC detecting condition:

The voltage does not reach 4.1 V after the backup battery is charged for 7 hours in total (not continuously).

Trouble symptom:

RED LED illuminates.

CAUTION:

After the Data Communication Module is replaced, registrations of COMM Check 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 .
Read the DTC of [Telematics] using the Subaru Select Monitor. Ref. to TELEMATICS SYSTEM (DIAGNOSTICS)>DIAGNOSTIC TROUBLE CODE (DTC) .

Is DTC B2A0F displayed? (Current malfunction)

Yes : Go to 2.

No : Even if DTC is displayed, the circuit has returned to a normal condition at this time. Reproduce the failure, and then perform the diagnosis again.

In this case, temporary poor contact of connector, temporary open or short circuit of harness may be the cause.
CHECK THE BACKUP BATTERY .
Check the backup battery unit. Ref. to ENTERTAINMENT & MONITORING>DATA COMMUNICATION MODULE .

Is the check result OK?

Yes : Replace the Data Communication Module. Ref. to ENTERTAINMENT & MONITORING>DATA COMMUNICATION MODULE .

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