DTC B1809: Short In Passenger's Airbag

Diagnosis start condition: 

When the ignition voltage is 10 - 16 V.

DTC detecting condition: 

Short circuit malfunction between passenger's airbag circuit and other circuit

Wiring diagram: 

Airbag system Ref. to WIRING SYSTEM>AIRBAG SYSTEM>WIRING DIAGRAM

Courtesy of SUBARU OF AMERICA, INC.

1. CHECK POOR CONTACT OF CONNECTORS  .

   Check for poor contact of the connectors between the airbag control module and the passenger's airbag module.

   Is there poor contact?

   Yes  : Replace the airbag main harness.

   No  : Go to  2.

2. CHECK AIRBAG MAIN HARNESS (PASSENGER'S AIRBAG HARNESS) (SHORTED BETWEEN LINES)  .
   1. Turn the ignition switch to OFF, and wait for 60 seconds or more after disconnecting the ground terminal from the battery sensor. Ref. to REPAIR CONTENTS>NOTE>BATTERY
   2. Disconnect the connector (AB46) from the roll connector.
   3. Disconnect the connector (AB86) from the driver's knee airbag module.
   4. Disconnect the connector (AB83) from the passenger's airbag module.
   5. Disconnect the connectors (AB41, AB42, AB43) from airbag control module.
   6. Connect the connector (1BF) in the test harness BF to the connectors (AB41, AB42, AB43).
   7. Measure the resistance between connector (AB83) of the passenger's side airbag module and all connector terminals in the test harness BF.
      CAUTION:

      Connect the test harness AT terminal to the connector (AB83) terminal and contact a tester to the test harness AT. 

      Connector & terminal 

      (AB83) No. 1 - All terminals in test harness BF (except for (3BF) No. 4):

      (AB83) No. 2 - All terminals in test harness BF (except for (9BF) No. 5):

   Is the resistance 1 MΩ or more?

   Yes  : Go to  3.

   No  : Replace the airbag main harness along with body harness.

3. CHECK AIRBAG CONTROL MODULE  .
   1. Disconnect the test harness BF from the connectors (AB41, AB42, AB43).
   2. Connect the connectors (AB41, AB42, AB43) to the airbag control module.
   3. Connect the connector (AB46) to the roll connector.
   4. Connect the connector (AB86) to the driver's knee airbag module.
   5. Using test harness AT, short the terminals No. 1 and No. 2 of connector (AB83).

      Connector & terminal 

      (AB83) No. 1 - (AB83) No. 2:

   6. Install the ground terminal to the battery sensor and turn the ignition switch to ON. Ref. to REPAIR CONTENTS>NOTE>BATTERY
   7. Execute the inspection mode. Ref. to AIRBAG (DIAGNOSTICS)>INSPECTION MODE 
   8. Read the DTC of [Airbag] using the Subaru Select Monitor. Ref. to AIRBAG (DIAGNOSTICS)>DIAGNOSTIC TROUBLE CODE (DTC) 

   Is DTC B1805 displayed? (Current code)

   Yes  : Replace the passenger's airbag module. Ref. to AIRBAG SYSTEM>PASSENGER'S AIRBAG MODULE>REMOVAL

   No  : Replace the airbag control module. Ref. to AIRBAG SYSTEM>AIRBAG CONTROL MODULE>REMOVAL