DTC B2A0D: Airbag Signal

Diagnosis start condition: 

When ignition switch is ON.

DTC detecting condition: 

Either the regular signal or collision detection signal cannot be detected from the airbag control module for at least 30 seconds.

Trouble symptom: 

• ACN function does not operate.
• RED LED illuminates.

Wiring diagram: 

Telematics Ref. to WIRING SYSTEM>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 B2A0D displayed? (Current code)

   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. CHECK DTC  .

   Read the DTC of [Airbag] using the Subaru Select Monitor. Ref. to AIRBAG (DIAGNOSTICS)>DIAGNOSTIC TROUBLE CODE (DTC)

   Are any DTCs displayed? (Current code)

   Yes  : Perform the diagnosis for the displayed DTCs of airbag. Ref. to AIRBAG (DIAGNOSTICS)>DIAGNOSTIC TROUBLE CODE (DTC)>LIST

   No  : Go to  3.

3. CHECK HARNESS (OPEN CIRCUIT)  .
   1. Turn the ignition switch to OFF.
   2. Disconnect the airbag control module connector.
   3. Disconnect the DCM connector.
   4. Using a tester, measure the resistance between the DCM connector and airbag control module connector.
      CAUTION:

      To measure the voltage and resistance of airbag system component, be sure to use the specified test harness. Ref. to  AIRBAG (DIAGNOSTICS)>GENERAL DESCRIPTION 

      Connector & terminal 

      (i105) No. 18 - (2BF) No. 7:

   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)  .

   Using a tester, measure the resistance between DCM connector and chassis ground.

   Connector & terminal 

   (i105) No. 18 - 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. Using a tester, measure the voltage between DCM connector and chassis ground.

      Connector & terminal 

      (i105) No. 18 (+) - Chassis ground (-):

   Is the voltage less than 1 V?

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

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