DTC B2A0B: Green Led Circuit

Diagnosis start condition: 

When ACC is ON.

DTC detecting condition: 

The following conditions occur for at least 50 ms.

• Current in GREEN LED is less than 1 MA. (Improper GREEN LED connection, etc.)
• Current in GREEN LED is more than 200 MA. (Short-circuited GREEN LED, etc.)

Trouble symptom: 

RED LED illuminates.

Wiring diagram: 

Telematics Ref. to WIRING SYSTEM (IMPREZA MODEL)>TELEMATICS SYSTEM>WIRING DIAGRAM . Ref. to WIRING SYSTEM (CROSSTREK MODEL (EXCEPT FOR HEV))>TELEMATICS SYSTEM>WIRING DIAGRAM . Ref. to WIRING SYSTEM (CROSSTREK MODEL (HEV))>TELEMATICS SYSTEM>WIRING DIAGRAM .

Courtesy of SUBARU OF AMERICA, INC.

1. CHECK DTC  .
   1. Turn the ignition switch to ON.
   2. Read the DTC of [Telematics] using the Subaru Select Monitor. Ref. to TELEMATICS SYSTEM (DIAGNOSTICS)>DIAGNOSTIC TROUBLE CODE (DTC) .

   Is DTC B2A0B 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.

   NOTE: In this case, temporary poor contact of connector, temporary open or short circuit of harness may be the cause.
2. PERFORM ACTIVE TEST  .

   Using the Subaru Select Monitor, check the following items in the [Active Test] of [Telematics]. Ref. to TELEMATICS SYSTEM (DIAGNOSTICS)>ACTIVE TEST .

   • GREEN LED Lighting

   Does the GREEN LED illuminate?

   Yes:  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.

   NOTE: In this case, temporary poor contact of connector, temporary open or short circuit of harness may be the cause.

   No:  Go to  3.

3. CHECK HARNESS (OPEN CIRCUIT)  .
   1. Turn the ignition switch to OFF.
   2. Disconnect the telematics button connector.
   3. Disconnect the DCM connector.
   4. Measure the resistance between telematics button connector and DCM connector.

      Connector and terminal 

      (i270) No. 3 - (R463) No. 4:

      (R463) No. 1 - Chassis ground:

   Is the resistance 1 Ω or less?

   Yes:  Go to  4.

   No:  Repair or replace the open circuit of harness.

4. CHECK HARNESS (GROUND SHORT CIRCUIT)  .

   Measure the resistance between DCM connector and chassis ground.

   Connector and terminal 

   (i270) No. 3 - Chassis ground:

   Is the resistance 1 MΩ or more?

   Yes:  Go to  5.

   No:  Repair or replace the short circuit of the harness.

5. CHECK THE CONNECTOR (SHORT CIRCUIT TO POWER SUPPLY)  .
   1. Turn the ignition switch to ON.
   2. Measure the voltage between DCM connector and chassis ground.

      Connector and terminal 

      (i270) No. 3 (+) - Chassis ground (-):

      (R463) No. 1 (+) - Chassis ground (-):

   Is the voltage less than 1 V?

   Yes:  Go to  6.

   No:  Repair or replace the short circuit of the harness. After the repair, Go to  7.

6. CHECK THE TELEMATICS BUTTON (GREEN LED) UNIT  .
   1. Turn the ignition switch to OFF.
   2. Check that the telematics button (GREEN LED) illuminates when battery voltage is applied to the telematics button (GREEN LED) unit.
   CAUTION: Never connect the battery voltage terminals in reverse polarity, because reversed connection damages the telematics button (LED).

   Terminals 

   No. 4 (+) - No. 1 (-):

   Does the telematics button (GREEN LED) illuminate?

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

   No:  Replace the telematics button. Ref. to ENTERTAINMENT & MONITORING>SWITCHES AND HARNESS .

7. CHECK THE TELEMATICS BUTTON (GREEN LED) UNIT  .
   1. Turn the ignition switch to OFF.
   2. Check that the telematics button (GREEN LED) illuminates when battery voltage is applied to the telematics button (GREEN LED) unit.
   CAUTION: Never connect the battery voltage terminals in reverse polarity, because reversed connection damages the telematics button (LED).

   Terminals 

   No. 4 (+) - No. 1 (-):

   Does the telematics button (GREEN LED) illuminate?

   Yes:  The telematics button (LED) is not malfunctioning. Finish the diagnosis.

   No:  Replace the telematics button. Ref. to ENTERTAINMENT & MONITORING>SWITCHES AND HARNESS .